Upload
others
View
4
Download
0
Embed Size (px)
Citation preview
This article was downloaded by: [193.191.134.1]On: 16 January 2012, At: 23:52Publisher: Taylor & FrancisInforma Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House,37-41 Mortimer Street, London W1T 3JH, UK
European Journal of PhycologyPublication details, including instructions for authors and subscription information:http://www.tandfonline.com/loi/tejp20
Six new Actinella (Bacillariophyta) species from PapuaNew Guinea, Australia and New Zealand: furtherevidence for widespread diatom endemism in theAustralasian regionKoen Sabbe a , Koenraad Vanhoutte a , Rex L. Lowe b , Elizabeth A. Bergey c , Barry J.F. Biggsc , Steve Francoeur d , Dominic Hodgson e & Wim Vyverman aa Department of Biology, Laboratory of Protistology & Aquatic Ecology, University of Gent, K.L. Ledeganckstraat 35, 9000 Gent, Belgiumb Department of Biological Sciences, Bowling Green State University, Bowling Green, OH43403, USAc National Institute of Water & Atmospheric Research Ltd, Kyle Street, Riccarton,Christchurch, PO Box 8602, New Zealandd Biological Sciences Department, University of Alabama, Box 870206, A-122 Bevill,Tuscaloosa, AL 35487-0206, USAe British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 OET, UK
Available online: 03 Jun 2010
To cite this article: Koen Sabbe, Koenraad Vanhoutte, Rex L. Lowe, Elizabeth A. Bergey, Barry J.F. Biggs, Steve Francoeur,Dominic Hodgson & Wim Vyverman (2001): Six new Actinella (Bacillariophyta) species from Papua New Guinea, Australia andNew Zealand: further evidence for widespread diatom endemism in the Australasian region, European Journal of Phycology,36:4, 321-340
To link to this article: http://dx.doi.org/10.1080/09670260110001735478
PLEASE SCROLL DOWN FOR ARTICLE
Full terms and conditions of use: http://www.tandfonline.com/page/terms-and-conditions
This article may be used for research, teaching, and private study purposes. Any substantial or systematicreproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form toanyone is expressly forbidden.
The publisher does not give any warranty express or implied or make any representation that the contentswill be complete or accurate or up to date. The accuracy of any instructions, formulae, and drug doses shouldbe independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims,proceedings, demand, or costs or damages whatsoever or howsoever caused arising directly or indirectly inconnection with or arising out of the use of this material.
http://www.tandfonline.com/loi/tejp20http://dx.doi.org/10.1080/09670260110001735478http://www.tandfonline.com/page/terms-and-conditions
Eur. J. Phycol. (2001), 36 : 321–340. Printed in the United Kingdom 321
Six new Actinella (Bacillariophyta) species from Papua New
Guinea, Australia and New Zealand: further evidence for
widespread diatom endemism in the Australasian region
KOEN SABBE1, KOENRAAD VANHOUTTE1, REX L. LOWE2,
ELIZABETH A. BERGEY3, BARRY J. F. BIGGS3, STEVE FRANCOEUR4,
DOMINIC HODGSON5 AND WIM VYVERMAN1
"Department of Biology, Laboratory of Protistology & Aquatic Ecology, University of Gent, K. L. Ledeganckstraat 35,
9000 Gent, Belgium
#Department of Biological Sciences, Bowling Green State University, Bowling Green, OH 43403, USA
$National Institute of Water & Atmospheric Research Ltd, Kyle Street, Riccarton, Christchurch, PO Box 8602, New Zealand
%Biological Sciences Department, University of Alabama, Box 870206, A-122 Bevill, Tuscaloosa, AL 35487-0206, USA
&British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 OET, UK
(Received 6 August 2000; accepted 20 March 2001)
Examination of sediment samples from oligo-and dystrophic ponds, lakes and streams in Papua New Guinea, Australia and
New Zealand revealed a hitherto unknown diversity of the diatom genus Actinella Lewis. Six new species are proposed, viz.
Actinella aotearoaia sp. nov., A. giluwensis sp. nov., A indistincta sp. nov., A. muylaertii sp. nov., A. parva sp. nov. and A.
pulchella sp. nov. All species are heteropolar, both in girdle and valve view. Novel information on the genus Actinella
includes the observations of two ribbon-shaped, valve-appressed plastids in A. aotearoaia and A. pulchella, and the presence
of long mucilage stalks in A. aotearoaia. It is argued that, despite recent proposals to reduce the genera Actinella and
Desmogonium Ehrenberg to the rank of subgenera of Eunotia, they should be kept separate until the taxonomic significance
of their distinctive morphological features (such as heteropolarity) is fully assessed. The new species appear to be endemic
to Australasia and have distinct biogeographies within this region. Except for A. aotearoaia, all species are present in
Tasmania; A. indistincta and A. pulchella have also been found in New Zealand (Stewart Island). A. aotearoaia is common
in several localities in New Zealand but was also found near Sydney on the Australian mainland. Actinella giluwensis has
only been observed in material from Papua New Guinea. The record of A. punctata for the latter country constitutes the
first confirmed record for this species outside North America and Europe. The discovery of the new Actinella species again
confirms the importance of the Australasian region as a major centre of microalgal biodiversity and endemism.
Key words : Actinella, Australia, Bacillariophyta, biogeography, endemism, morphology, New Zealand, Papua New Guinea,
taxonomy
Introduction
The subclass Eunotiophycidae, belonging to the
raphid pennate diatoms (Bacillariophyceae), is
characterized by the structure of the raphe, which is
simple and not fully integrated in the valve pattern
centre, and the presence of rimoportulae in most
genera (Round et al., 1990; Vyverman et al., 1998).
It currently comprises six genera: Desmogonium
Ehrenberg, Eunophora Vyverman, Sabbe & Mann,
Eunotia Ehrenberg, Peronia de Bre!bisson & Arnottex Kitton and Semiorbis Patrick. Actinella differs
Correspondence to: Koen Sabbe. Tel. 32 (0) 92645069. Fax:32 (0) 92645334. e-mail : Koen.Sabbe!rug.ac.be
from Desmogonium, Eunophora, Eunotia and
Semiorbis in being asymmetrical about the median
transapical plane, and from Peronia in the marginal,
not subcentral, position of the raphe.
The genusActinellawas describedbyLewis (1863)
from a shallow, spring-fed pond in New Hampshire
(USA). Twenty-nine species have hitherto been
described (Table 1), most of which are found in acid
waters (Round et al., 1990). The main centres of
diversity are tropical South America (12 species)
and Africa (11 species), while from the Northern
Hemisphere (North America and Europe) only four
species are known. To date, only two species have
been reported from Australasia, viz. A. tasmaniensis
from Tasmania (Hustedt, 1952) and A. modesta
from New Caledonia (Moser et al., 1998).
Dow
nloa
ded
by [
193.
191.
134.
1] a
t 23:
52 1
6 Ja
nuar
y 20
12
322
New
Actin
ellasp
p.fro
mA
ustra
lasia
Table 1. Actinella species list. Under Biogeography only recently confirmed or properly illustrated records are listed. The reference list is not exhaustive
Taxon Biogeography References
Type locality Europe
A. fontellii Woodhead & Tweed Europe (Sweden) Fontell (1917), Woodhead & Tweed (1957)
A. karelica Mo$ lder Europe (Scandinavia) Mo$ lder (1951)A. pliocenica He! ribaud & M. Peragallo Europe (France) He! ribaud (1902)
Type locality North America
A. punctata Lewis North America, Europe (Scandinavia), Papua New Guinea Kociolek et al. (1997), Lewis (1863), this study
Type locality South America
A. brasiliensis Grunow in Van Heurck South America (e.g. Brazil, Guyana, Ecuador, Surinam), Japan Metzeltin & Lange-Bertalot (1998), Okuno (1964), Van Heurck (1881)a
A. mirabilis (Eulenstein?) Grunow in Van Heurck South America (e.g., Brazil, Ecuador) De Oliveira & Steinitz-Kannan (1992), Uherkovich (1986), Van Heurck (1881)
A. guinanensis Grunow in Van Heurck South America (e.g., Brazil, Guyana, Ecuador) Metzeltin & Lange-Bertalot (1998), Van Heurck (1881)
A. scala Brun South America (Barbados) Brun (1896)
A. peronioides Hustedt South America (Brazil, Venezuela) Hustedt (1952), Metzeltin & Lange-Bertalot (1998)
A. eunotioides Hustedt South America (Venezuela) Hustedt (1952), Metzeltin & Lange-Bertalot (1998)
A. robusta Hustedt South America (Brazil, Ecuador) Hustedt (1952), Metzeltin & Lange-Bertalot (1998)
A. gessneri Hustedt South America (Brazil) Hustedt (1965)
A. siolii Hustedt South America (Brazil, Venezuela) Hustedt (1965), Metzeltin & Lange-Bertalot (1998)
A. leontopithecus-rosalia da Costa South America (Brazil) da Costa (1995)
A. pararobusta Metzeltin & Lange-Bertalot South America (Brazil) Metzeltin & Lange-Bertalot (1998)
A. pseudohantzschia Metzeltin & Lange-Bertalot South America (Brazil, Guyana) Metzeltin & Lange-Bertalot (1998)
Type locality Africa
A. cholnokii Woodhead & Tweed Africa (South Africa) Cholnoky (1954a), Woodhead & Tweed (1957)
A. raytonensis (Cholnoky) Woodhead & Tweed Africa (South Africa) Cholnoky (1955), Woodhead & Tweed (1957)
A. theronii (Cholnoky) Woodhead & Tweed Africa (South Africa) Cholnoky (1954b), Woodhead & Tweed (1957)
A. africana Woodhead & Tweed Africa (Sierra Leone) Woodhead & Tweed (1957)
A. spathulifera Woodhead & Tweed Africa (Sierra Leone) Woodhead & Tweed (1957)
A. australis (Manguin) Kociolek, Rhode & Williams Africa (Madagascar) Kociolek et al. (1997)
A. manguinii Kociolek, Rhode & Williams Africa (Madagascar) Kociolek et al. (1997)
A. candelabrum (Manguin) Kociolek & Rhode Africa (Madagascar) Bourelly & Manguin (1949), Kociolek & Rhode (1998)
A. madagascariensis (Manguin) Kociolek & Rhode Africa (Madagascar) Bourelly & Manguin (1949), Kociolek & Rhode (1998)
A. bourrellyi (Manguin) Kociolek & Rhode Africa (Madagascar) Bourelly & Manguin (1949), Kociolek & Rhode (1998)
A. reviersii (Manguin) Kociolek & Rhode Africa (Madagascar) Bourelly & Manguin (1949), Kociolek & Rhode (1998)
Type locality Australasia
A. tasmaniensis Hustedt Australia (Tasmania) Hustedt (1952), Vyverman et al. (1995), this study
A. modesta Moser, Lange-Bertalot & Metzeltin New Caledonia Moser et al. (1998)
A. aotearoaia Lowe, Biggs & Francoeur New Zealand This study
A. giluwensis Sabbe & Vyverman Papua New Guinea This study
A. indistincta Vyverman & Bergey Australia (Tasmania), New Zealand This study
A. muylaertii Sabbe & Vyverman Australia (Tasmania) This study
A. parva Vanhoutte & Sabbe Australia (Tasmania), New Zealand This study
A. pulchella Sabbe & Hodgson Australia (Tasmania), New Zealand This study
A. comperei Sabbe, Vanhoutte & Vyverman Australia (Tasmania) Sabbe et al. (2000)
a See text for further references and remarks on this species.
Dow
nloa
ded
by [
193.
191.
134.
1] a
t 23:
52 1
6 Ja
nuar
y 20
12
K. Sabbe et al. 323
The present study forms part of a taxonomic and
biogeographic investigation of the diatom floras of
three Australasian countries (Papua New Guinea,
Australia and New Zealand) which has already led
to the discovery of several endemic diatom taxa,
including the genus Eunophora and five new fresh-
water Biremis species (Vyverman, 1988; Vyverman
et al., 1997, 1998). An investigation of the benthic
diatom communities of predominantly dystrophic
subalpine lakes, tarns and streams in the above-
mentioned countries revealed the presence of six
new species belonging to the genus Actinella ; a
seventh new species is described elsewhere (Sabbe
et al., 2000). Below, we present a detailed morpho-
logical description of each species based on light
and scanning electron microscopy. The taxonomic
status of Actinella and other genera belonging to the
Eunotiophycidae as well as the biogeography and
ecology of the new Actinella species are described
and discussed.
Materials and methods
Samples were scraped from diverse littoral substrata(surface sediments, rocks and submerged macroalgae andmacrophytes) of dystrophic and (ultra-)oligotrophiclakes, ponds and streams in Papua New Guinea,Australia (New South Wales, Tasmania) and NewZealand. Detailed information on sampling sites anddates is given in Table 2. In the Tasmanian highlands,where most studied materials come from, two limno-logical regions are recognized, namely a western and aneastern province. Lakes in these two provinces differ inoptical and chemical properties (caused by edaphic,climatic, geological and vegetational differences). West-ern lakes are strongly humic, moderately to highlydystrophic and have low pH and alkalinity, while easternlakes are less acidic, (ultra-)oligotrophic and have higheralkalinity. In between these two regions lies a corridorzone where intermediate-type lakes can be found (hence-forth called corridor lakes ; Tyler, 1992; Vyverman et al.,1996). The distribution of each Actinella species found inTasmania is described in relation to this limnologicalgradient. More information on the limnological featuresof the lakes listed can be found in Vyverman et al. (1995,1996, 1997).
Samples were fixed with 3–4% formaldehyde.Specimens of Actinella brasiliensis were investigated onAWH (Van Heurck Collection, Antwerp, Belgium) slidesVIII 37 B 6 (Weissflog collection 553, Surinam) and (IX61 A 4 (Donkin 2523, Iganape, Surinam). When possible,observations were made on live material (Figs 1, 2) inorder to study plastid structure and life form.
Subsamples were digested with concentrated acids(H
#SO
%or a H
#SO
%}HNO
$mixture: Patrick & Reimer,
1966) and washed several times with distilled water. Forlight microscopy (LM), part of the samples were driedonto glass coverslips, mounted in Naphrax and studiedusing a Zeiss Axioplan 2 equipped with differentialinterference contrast optics (DIC), a Leitz Ortholux(DIC) or an Olympus BH2 (bright field optics). Some T
able
2.L
istofsa
mpling
site
sand
date
s,habitatty
pe
and
refe
rence
tost
udie
spro
vid
ing
det
ailed
info
rmation
on
morp
hom
etric
and
wate
rch
emistr
ydata
.N
ote
thatfo
rth
eA
ust
ralian
main
land
and
the
New
Zea
land
loca
lities
no
such
data
are
available
Loca
lity
Habitatty
pe
Date
Wate
rch
emistr
y
Aust
ralia
Tasm
ania
Dyst
rophic
tooligotr
ophic
,hum
ichig
hla
nd
lakes
and
tarn
sbet
wee
n490
and
1202
maltitude
Feb
.–D
ec.1994,F
eb.1995
Vyver
man
etal.
(1996)
RoyalN
ationalPark
,Sydney
,N
ewSouth
Wale
sA
cidic
cree
k(K
angaro
oC
reek
)dra
inin
gSydney
sandst
one
at³
50
maltitude
July
1997
–
New
Zea
land
Ariel
sT
arn
,H
arm
an
Pass
,A
rthur’s
Range
National
Park
,South
Isla
nd
Tw
oalp
ine
aci
d-w
ate
rta
rns
at1320
maltitude
Marc
h1997
–
Outlet
ofsm
all
tarn
close
totw
ota
rns
(cf.
above)
Dec
.1998
–
O’C
onner
Cre
ek(a
tN
XH
iway
6),
Om
oer
aSaddle
,
Wes
tland,South
Isla
nd
‘Bla
ckw
ate
r’st
ream
at400
maltitude
Jan.1992,Ja
n.1997
pH
¯5,co
nduct
ivity¯
10
µS
cm−"
Table
Hill,
Ste
wart
Isla
nd
Aci
dic
tarn
sand
stre
am
sin
the
pen
alp
ine
zone
ofnative
gra
sses
at380
maltitude
Oct
.1997
pH
!7
Papua
New
Guin
eaM
ountG
iluw
e,South
ern
Hig
hla
nds
Pro
vin
ceSm
all
alp
ine
aci
dic
lake
at3540
maltitude
Aug.–
Oct
.1987
pH
¯6±2
,co
nduct
ivity¯
15
µS
cm−"
Vyver
man
(1991)
Dow
nloa
ded
by [
193.
191.
134.
1] a
t 23:
52 1
6 Ja
nuar
y 20
12
324New Actinella spp. from Australasia
coverslips were attached to aluminium specimen stubswith double-sided tape and silver paint and sputter-coated with an Au}Pd alloy for examination withscanning electron microscopy (SEM). Sample materialwas also directly air-dried onto specimen stubs andsputter-coated. SEM was performed with a Jeol JSM-840operated at 15 kV or a Hitachi S-2700. In order toobserve soft parts of diatoms (stalks and pads), portionsof some samples were mounted on SEM stubs prior toacid digestion. Formaldehyde was removed over 3 daysemploying a series of distilled water rinses. Samples werethen fixed with glutaraldehyde (25% final concentration)overnight, then post-fixed with OsO
%(0±2% final con-
centration) for 2 h. Excess fixative was removed using aseries of distilled water rinses. Samples were thendehydrated with an ascending series of ethanol rinses(25%, 40%, 60%, 80%, 95%, 100% ¬3), then im-mersed in hexamethyldisilazane for 5 min (Nation, 1983).Following immersion, specimens were mounted, coatedand observed as above.
Frustule dimensions (length (L), width (W) and striadensity (S)) were determined on 20 valves of each species,unless stated otherwise. For each dimension theminimumand maximum values are given, whilst the average valueand the standard deviation are given in parentheses.Terminology used in the description of the structures ofthe siliceous cell wall is based on Hendey (1964: valveoutlines and structural types), Anonymous (1975), Rosset al. (1979), Cox & Ross (1980) and Round et al. (1990:cingulum and raphe structures).
Results
Actinella aotearoaia R. L. Lowe, B. J. F. Biggs &
F. Francoeur, sp. nov.
Figs 2–20
Cellulae clavatae aspectu cincturae, 9±0–31±2(20±1³6±3) µm longae, substrato affixae per pen-dunculum mucilaginum longum. Chromatophora
elongata 2 ad valvas appressa. Valvae valde clavatae
et leviter semi-arcuatae, 2±5–3±5 (2±5³0±4) µm lataein media parte ; specimina grandia distincte solei-
formia. Capitus-polus 3±3–6±2 (4±5³0±7) µm latus,rotundatus, valde tumescens in latere ventrali et
dorsali, valde asymmetricus quoad axem apicalem.
Basis 1±0–2±2 (1±4³0±3) µm lata, non tumescens.Striae 16–20 (18±3³1±4) in 10 µm, parallelae, capito-polo versus valde radiatae. Areolae circulares volis
occlusae. Spinulae marginales nullae. Sternum
indistinctum. Raphe brevis magnopere in limbo
valvarum sita ; apices distales earum in facie val-
varum flexi. Helictoglossae parvae, sed plerumque
in latere ventrali valvae positae semper manifestae.
Rimoportula una, ad laterem ventralem basis vel
capiti-poli posita, in transitione faciei valvarum
limbo; in frustulo completo rimoportulae valvarum
semper ad polos opposites positae. Cingulum ex 4
copulis apertis curvatis porosis constans.
Cells clavate in girdle view, 9±0–31±2(20±1³6±3) µm long, attached to the substratum via
Figs 1, 2. Light microscopy of living Actinella species. Fig.
1. A. pulchella. Arrowheads show small round structures
(possibly pyrenoids). Fig. 2. A. aotearoaia. Scale bar
represents 10 µm.
a long mucilaginous stalk. Two elongate, valve-
appressed plastids. Valves strongly clavate and
slightly semi-arcuate, 2±5–3±5 (2±5³0.4) µm wide atmidpoint ; larger specimens distinctly sole-shaped.
Headpole 3±3–6±2 (4±5³0±7) µm wide, rounded,strongly bulged on the dorsal and ventral side, and
strongly asymmetrical about the apical plane. Foot-
pole 1±0–2±2 (1±4³0±3) µm wide, not tumescent.Striae 16–20 (18±3³1±4) in 10 µm, parallel to radiateat the headpole. Areolae round, occluded by volate
vela. No marginal spines. Sternum indistinct. Raphe
short, largely situated on the valve mantle ; distal
ends bent onto the valve face. Helictoglossae small,
but usually clearly visible on the ventral side of the
valve. Rimoportula one per valve, lying on the
ventral side of the foot- or headpole on the valve
face}mantle transition; in a complete frustule, therimoportulae of the two valves always lie at opposite
poles. Cingulum composed of 4 open, strongly
curved, porous copulae.
E : This species is named for Aotearoa,
the Maori name for New Zealand, meaning ‘land of
the long white cloud’.
H : BM slide 100921, The Natural History
Museum, Department of Botany, London.
I : BRM slide Zu5}35 Friedrich Hustedt-
Dow
nloa
ded
by [
193.
191.
134.
1] a
t 23:
52 1
6 Ja
nuar
y 20
12
K. Sabbe et al. 325
Figs 3–20. Light (Figs 10–14, 16–20) and SEM (Figs 3–9, 15) micrographs of Actinella aotearoaia from different localities :
Figs 3, 8, 12, 14, 16–17, 20, Ariels Tarn, New Zealand (holotype population) ; Figs 4–7, 9, O’Conner Creek, New Zealand;
Figs 10, 11, Kangaroo Creek, Australia ; Figs 13, 15, unnamed tarn, Stewart Island, New Zealand. Fig. 3. External valve
view showing external rimoportula opening (arrow). Fig. 4. External girdle view of two cells on a bifurcating stalk. Fig. 5.
Oblique external view. Note the two raphe branches (R) and the opening of the rimoportula (L). Fig. 6. Internal view of the
headpole showing the helictoglossa (H) and the rimoportula (L). Fig. 7. External view of the footpole with areolar
occlusions (P). Fig. 8. External oblique view showing curved, open copulae. Fig. 9. Rimoportula (L) in internal footpole
view. Fig. 10. Possible initial valve. Figs 11–14, 16, 17. Valve views. Arrowheads in Figs 14 and 17 indicate striae that are
out of phase and hence the position of the sternum. Fig. 15. External valve view. Figs 18–20. Girdle views. Note the distinct
raphe branches and the copulae with scattered areolae. Scale bars represent 10 µm (Figs 3, 4, 10–14, 16–20), 5 µm (Fig. 5)
and 1 µm (Figs 6–9, 15) ; scale bar for Figs 14, 16 and 17 is shown in Fig. 12.
Arbeitsplatz fu$ r Diatomeenkunde, Bremerhaven;CAS slide 220053, California Academy of Sciences,
San Francisco; slide KS0101, the Herbarium, Uni-
versity of Gent (GENT).
T : Ariels Tarn (171°25«0§E, 42°56«26§S),Harman Pass (Arthur’s Range National Park,
South Island, New Zealand), surface sediment
samples.
Five different populations of this species have been
studied.Morphometric analyses revealed significant
differences in headpole width and stria density
between some of these populations (unpublished
data, but compare e.g. Fig. 13, which depicts a
narrow, more finely striated valve from Stewart
Island, with the valves from Ariels Tarn in Figs 12,
14, 16 and 17). As the taxonomic significance of this
phenomenon is not yet clear (i.e. whether this
variability has a genetic basis or whether it merely
reflects differing environmental conditions or
different stages in the cell size reduction cycle), we
have based the protologue (and the description
below) of A. aotearoaia on the populations from
Ariels tarn.
Living cells of A. aotearoaia have two ribbon-like,
sometimes curled plastics, one under each valve
(Fig. 2). A small droplet is present just above the
Dow
nloa
ded
by [
193.
191.
134.
1] a
t 23:
52 1
6 Ja
nuar
y 20
12
326New Actinella spp. from Australasia
centre of the cell. The cells were observed at the ends
of relatively long mucilage stalks that may bifurcate
following cell division (Figs 2, 4). Cells are strongly
clavate in girdle view (Figs 18–20) ; in valve view,
they are often distinctly sole-shaped. However, in
valves from Stewart Island (Figs 13, 15) and
Kangaroo Creek (Figs 10, 11) this was much less
pronounced. A large valve from Kangaroo Creek
(Fig. 10; 41±5 µm long) which has a slight centralinflation probably represents an initial valve. A.
aotearoaia is the only species described in this paper
which had intact areolar occlusions. Externally, the
volate vela only partially occlude the areolae, which
results in curved openings (Fig. 7). Internally, the
areolae appear as simple pores (Fig. 9). The sternum
is very narrow and usually only visible when some
striae are out of phase (Figs 14, 17). The short raphe
branches are largely situated on the mantle and thus
only visible in girdle view (Figs 18–20) ; they are
often irregularly curved (Figs 3, 5). There are two
sessile rimoportulae per frustule, lying at diagonally
opposite poles. The cingulum is composed of 4
open, curved copulae. Apart from one longitudinal
row of puncta on the advalvar side of each copula
(Figs 5, 8), numerous large puncta lie randomly
scattered on the copulae, which gives this species a
distinctive appearance in girdle view (Figs 18–20).
D : Actinella aotearoaia is present, and
often dominant (e.g. up to 35% in the epiphyton of
O’Conner Creek, Westland) in several epiphytic (on
Batrachospermum Roth, Stigonema Agardh and
mosses) and sediment samples from the South
Island of New Zealand and Stewart Island. It is also
present in samples from Kangaroo Creek (Royal
National Park, Sydney) on the Australian main-
land. The specimen illustrated as Actinella
brasiliensis in Foged (1979, pl. XII, fig. 12) from the
North Island of New Zealand probably also belongs
to A. aotearoaia. To date, it has not been observed
in the Tasmanian material.
Actinella giluwensis K. Sabbe & W. Vyverman, sp.
nov.
Figs 21–30
Cellulae leviter clavatae aspectu cincturae, 141±2–176±7 (150±8³11±8) µm longae (n¯ 6). Structurachromatophororum incognita. Valvae clavatae,
leviter semi-arcuatae, margine ventrali concava et
margine dorsali convexa, 8±6–11±2 (9±8³0±8) µmlatae in media parte. Capitus-polus 16±8–20±0(18±3³1±4) µm latus, tumescens in latere ventrali etdorsali, sub-rostratus. Projectura apicalis posita in
centro capiti-poli. Basis 10±0–11±9 (10±7³0±8) µmlata, leviter tumescens, rotundata. Striae punctatae,
12–16 (14±2³1±2) in 10 µm, ad centrum parallelae,apices versus leviter radiatae. Areolae parvae,
circulares ; structura velorum incognita (possibiliter
erosa). Margo valvae spinulis simplicibus praedita.
Sternum angustum et indistinctum. Raphe brevis
magnopere in limbo valvarum sita ; apices distales
earum in facie valvarum flexi. Helictoglossae
distinctae, in latere ventrali valvae positae semper
manifestae. Rimoportulae duae, in limbo ad laterem
ventralembasis et in parte apicali capiti-poli positae.
Cingulum ex 4 copulis apertis ligulatis, seriebus
aliquot per copulam.
Cells slightly clavate in girdle view, 141±2–176±7(150±8³11±8) µm long (n¯ 6). Plastid structureunknown. Valves clavate, slightly semi-arcuate,
with ventral margin concave and dorsal margin
convex, 8±6–11±2 (9±8³0±8) µm wide at midpoint.Headpole 16±8–20±0 (18±3³1±4) µm wide, bulged onthe dorsal and ventral side, sub-rostrate. Footpole
10±0–11±9 (10±7³0±8) µm wide, slightly tumescent,rounded. Apical projection in the centre of the
headpole. Striae punctate, 12–16 (14±2³1±2) in10 µm, parallel in the centre to slightly radiate at the
poles. Areolae small, round; velum structure un-
known (possibly eroded). Small, simple spines are
present along the valve margin. Sternum narrow
and indistinct. Raphe short, largely situated on the
valve mantle ; distal ends bent onto the valve face.
Helictoglossae distinct, clearly visible on the ventral
side of the valve. Rimoportulae two per valve, on
the mantle on the ventral side of the footpole and in
the apical part of the headpole. Cingulum composed
of 4 open, ligulate copulae, with several rows of
poroids per copula.
E : This species is named for Mount
Giluwe, situated in the Southern Highlands Prov-
ince of Papua New Guinea.
H : BM slide 100922, The Natural History
Museum, Department of Botany, London.
I : BRM slide Zu5}36 Friedrich Hustedt-Arbeitsplatz fu$ r Diatomeenkunde, Bremerhaven;CAS slide 220054, California Academy of Sciences.
San Francisco; slide KS0102, The Herbarium,
University of Gent (GENT).
T : Outlet of unnamed lake (143°55«40§E, 06°03«08§S), Mount Giluwe (SouthernHighlands Province, Papua New Guinea, altitude
3540 m).
Only a few valves and complete frustules of this
species were observed. The areolae are pore-like ; no
occlusions could be observed (Figs 21, 22). The
raphe is largely situated on the valve mantle (Figs
21, 22, 26) although the terminal fissures can be seen
to extend onto the valve face in Figs 23, 24 and 30.
Spines are present along the whole valve face margin
(Figs 22–24, 27–30). The sternum is very narrow
Dow
nloa
ded
by [
193.
191.
134.
1] a
t 23:
52 1
6 Ja
nuar
y 20
12
K. Sabbe et al. 327
Figs 21–30. Light (Figs 23–25, 27–30) and SEM (Figs 21, 22, 26) micrographs of Actinella giluwensis from an unnamed
lake, Mount Giluwe, Papua New Guinea (holotype population). Fig. 21. Internal view of the headpole showing the
helictoglossa and rimoportula ; the sternum is arrowed. Fig. 22. Oblique view of footpole. Note the rimoportula
(arrowhead). Figs 23, 24. Valve views of headpole and complete valve. Note the distinct helictoglossae and the sternum
(arrowhead) in Fig. 23. Fig. 25. Girdle view. Fig. 26. Internal view of the headpole of the same valve as in Fig. 22. The
small rimoportula in the valve apex is arrowed. Fig. 27. Girdle view of headpole showing the marginal spines and the
puncta on the copulae. Figs 28, 29. Girdle view of the same footpole at different foci. In Fig. 28 the two rimoportulae,
situated between the valve apex and the relatively large helictoglossae, are arrowed. Fig. 30. Valve view of headpole. Scale
bars represent : 10 µm (Figs 23–25, 27–30) and 1 µm (Figs 21, 22, 26). Scale bar for Fig. 29 is shown in Fig. 28.
and can mainly be seen because striae are out of
phase on either side of it (Figs 21, 23). The
rimoportulae are sessile and can only be observed in
LM when the cells are viewed in girdle view (Fig. 28)
as they are relatively small and largely situated on
the valve mantle (Figs 21, 22, 26). The distinct
helictoglossae (Figs 21, 22, 26) are conspicuous in
both valve (Fig. 24) and girdle view (Fig. 28). The
copulae are only slightly curved near the apices. As
in A. aotearoaia there is one advalvar longitudinal
row of puncta on each copula (not shown); on the
rest of the copulae a few irregular rows of puncta are
present (Fig. 27).
This large species is reminiscent of Actinella
guinanensis (cf. Metzeltin & Lange-Bertalot, 1998)
from which it mainly differs in the medial (and not
dorsal) position of the apical point, and valve shape
(less bent, footpole only slightly tumescent).
Dow
nloa
ded
by [
193.
191.
134.
1] a
t 23:
52 1
6 Ja
nuar
y 20
12
328New Actinella spp. from Australasia
Figs 31–44. SEM (Figs 31–35, 44) and light (Figs 36–43) micrographs of Actinella indistincta from Oberon Tarn (Tasmania,
holotype population). Fig. 31. External girdle view of complete frustule. Note the advalvar rows of puncta on the copulae
(arrowheads) and the additional row of puncta in the middle of the copulae. Fig. 32. Detail of headpole of the same
frustule as in Fig. 31 showing the curved copulae. Arrowhead shows the external rimoportula opening. Fig. 33. External
view of footpole. Note the external rimoportula opening (arrowhead). Fig. 34. Detail of the footpole of the same frustule as
in Fig. 31. The rimoportula opening is arrowed. Fig. 35. Headpole of frustule shown in Fig. 44. The small rimoportula is
arrowed. Figs 36–41. Valve views. Figs 42–43. Girdle views. Fig. 44. Internal valve view. Arrowhead indicates the
rimoportula in the headpole. Scale bars represent : 10 µm (Figs 31, 36–44), 5 µm (Figs 33, 34) and 1 µm (Figs 32, 35). Scale
bar for Figs 37–43 is shown in Fig. 36.
Actinella giluwensis was previously illustrated as
Actinella punctata (partim) in Vyverman (1991, p1.
9, figs 2–5, 7, p1. 169, fig. D, p1. 170, fig. A).
D : This species was rare in the
epiphyton of oligotrophic highland tarns at con-
ductivities of 11–66 µS cm−" and pH 6–7, where it
was found together with Actinella punctata (see
below).
Actinella indistincta W. Vyverman & E. Bergey, sp.
nov.
Figs 31–44
Cellulae leviter clavatae aspectu cincturae, 15±0–36±4
Dow
nloa
ded
by [
193.
191.
134.
1] a
t 23:
52 1
6 Ja
nuar
y 20
12
K. Sabbe et al. 329
(23±8³5±8) µm longae (n¯ 12). Structura chro-matophororum incognita. Valvae leviter semi-
arcuatae et heteropolares, margine ventrali plus
minusve concave et margine dorsali convexa,
1±2–2±2 (1±6³0±3) µm latae in media parte. Capitus-polus 1±0–1±5 (1±2³0±1) µm latus, non tumescens.Basis 0±9–1±2 (1±1³0±1) µm lata, non tumescens.Striae per microscopium usitatum non facile de-
tectae, 26–30 (27±2³1±1) in 10 µm, ad centrumparallelae, apices versus leviter radiatae. Areolae
parvae, circulares ; structura velorum incognita
(possibiliter erosa). Sternum angustum et indis-
tinctum. Raphe brevis magnopere in limbo val-
varum sita ; apices distales earum in facie valvarum
flexi. Helictoglossae distinctae, in latere ventrali
valvae positae semper manifestae. Rimoportula
una, ad laterem ventralem basis vel capiti-poli
posita, in transitione faciei valvarum limbo; in
frustulo completo rimoportulae valvarum semper
ad polos oppositos positae. Cingulum probabiliter
ex 4 copulis apertis ligulatis porosis constans.
Cells slightly clavate in girdle view, 15–36±4(23±8³5±8) µm long (n¯ 12). Plastid structure un-known. Valves slightly semi-arcuate and hetero-
polar, with ventral margin more or less concave and
dorsal margin convex, 1±2–2±2 (1±6³0±3) µm wide atmidpoint. Headpole 1±0–1±5 (1±2³0±1) µm wide, nottumescent. Footpole 0±9–1±2 (1±1³0±1) µm wide,not tumescent. Striae often difficult to resolve with
the light microscope, 26–30 (27±2³1±1) in 10 µm,parallel in the centre to slightly radiate at the poles.
Velum structure unknown (possibly eroded). Ster-
num narrow and indistinct. Raphe short, largely
situated on the valve mantle ; distal ends bent onto
the valve face. Helictoglossae distinct, clearly visible
on the ventral side of the valve. Rimoportula one
per valve, lying on the ventral side of the foot- or
headpole on the valve face}mantle transition; in acomplete frustule, the rimoportulae of the two
valves always lie at opposite poles. Cingulum
probably composed of 4 open, ligulate, porous
copulae.
H : BM slide 100923, The Natural History
Museum, Department of Botany, London.
I : BRM slide Zu5}37 Friedrich Hustedt-Arbeitsplatz fu$ r Diatomeenkunde, Bremerhaven;CAS slide 220055, California Academy of Sciences,
San Francisco; slide KS0103, The Herbarium,
University of Gent (GENT).
T : Oberon Tarn, Tasmania, Australia.
Actinella indistincta is only slightly heteropolar,
both in valve (Figs 36–41) and girdle view (Figs
42–43). It can only be confused with A. parva (cf.
below), which has a similar size range but a
significantly lower stria density. The sternum is only
just visible in SEM (Fig. 32). The areolae are pore-
like ; no occlusions could be observed. The rimo-
portulae are small and sessile. There is only one
rimoportula per valve; within a frustule, they are
diagonally opposed (compare Figs 31, 32, 34). Each
copula has one advalvar row of puncta, and an
additional row in the middle of the valve (Figs 31,
32, 34).
D : Actinella indistincta was found in
one western (Oberon Tarn) and one corridor lake
(Twisted L.) in Tasmania , and in an unnamed tarn
on Stewart Island (New Zealand).
Actinella muylaertii K. Sabbe & W. Vyverman, sp.
nov.
Figs 45–61
Cellulae clavatae aspectu cincturae, 11±0–28±0(20±7³3±5) µm longae. Structura chromato-phororum incognita. Valvae valde clavatae, 1±5–2±5(2±2³0±3) µm latae in media parte, leviter semi-arcuatae, asymmetricae quoad axem apicalem.
Capitus-polus 5±0–7±0 (6±3³0±5) µm latus, valdetumescens in latere ventrali et dorsali, rostratus ad
capitatus. Basis 0±9–1±7 (1±2³0±2) µm lata, nontumescens. Striae 16–21 (18±9³1±2) in 10 µm,parallelae, capito-polo versus valde radiatae.
Areolae parvae, circulares ; structura velorum
incognita (possibiliter erosa). Spinulae marginales
nullae, sed margo valvae nonnumquam crista
angusta praedita. Sternum angustum. Raphe brevis
magnopere in limbo valvarum sita ; apices distales
earum in facie valvarum flexi. Helictoglossae
parvae, sed plerumque in latere ventrali valvae
positae semper manifestae. Rimoportula una, ad
laterem ventralem basis posita, in transitione faciei
valvarum limbo. Cingulum ex 4 copulis apertis
curvatis porosis constans.
Cells clavate in girdle view, 11±0–28±0(20±7³3±5) µm long. Plastid structure unknown.Valves strongly clavate, 1±5–2±5 (2±2³0±3) µm wideat midpoint, slightly semi-arcuate, asymmetrical
about the apical plane. Headpole 5±0–7±0(6±3³0±5) µm wide, strongly bulged on the dorsaland ventral side, rostrate to capitate. Footpole
0±9–1±7 (1±2³0±2) µm wide, not tumescent. Striae16–21 (18±9³1±2) in 10 µm, parallel to stronglyradiate at the headpole. Velum structure unknown
(possibly eroded). No marginal spines, but in some
specimens a narrow ridge is present along the valve
margin. Sternum narrow. Raphe short, largely
situated on the valve mantle ; distal ends bent onto
the valve face. Helictoglossae small, but usually
clearly visible on the ventral side of the valve.
Rimoportula one per valve, lying on the ventral side
Dow
nloa
ded
by [
193.
191.
134.
1] a
t 23:
52 1
6 Ja
nuar
y 20
12
330New Actinella spp. from Australasia
Figs 45–61. SEM (Figs 45–54) and light (Figs 55–61) micrographs of Actinella muylaertii from Lonely Tarn (Tasmania,
holotype population, Figs 45–47, 49, 51–61) and Reservoir 2 (Tasmania, Figs 48, 50). Fig. 45. External valvar view of the
headpole. Fig. 46. External valvar view of the footpole. The rimoportula opening is arrowed. Fig. 47. External ventral view
of a complete frustule. The opposed rimoportula openings are arrowed. Fig. 48. Internal valvar view showing the
rimoportula at the footpole (arrowhead). Figs 49, 50. Internal views of the headpole. Note the short raphe branch in Fig.
49. Fig. 51. External dorsal view of a complete frustule. Fig. 52. Girdle view of the headpoles and cingulum of a complete
frustule. Note the strongly curved, porous copulae and the siliceous marginal ridge. Fig. 53. External ventral view of a
complete frustule. Note the marginal ridge. Fig. 54. External valvar view of a headpole. Fig. 55. Girdle view of recently
divided cells. Fig. 56. Girdle view of a complete frustule. Note that the apex at the headpole is shown at a different focus.
Figs 57–61. Valve views showing range in size and shape. Scale bars represent : 10 µm (Figs 55–61) and 1 µm (Figs 45–54).
Scale bar for Figs 57–60 is shown in Fig. 61.
of the footpole on the valve face}mantle transition.Cingulum composed of 4 open, curved, porous
copulae.
E : This species is dedicated to our col-
league Koenraad Muylaert who provided us with
some of the material examined.
H : BM slide 100924, The Natural History
Museum, Department of Botany, London.
Dow
nloa
ded
by [
193.
191.
134.
1] a
t 23:
52 1
6 Ja
nuar
y 20
12
K. Sabbe et al. 331
I : BRM slide Zu5}38 Friedrich Hustedt-Arbeitsplatz fu$ r Diatomeenkunde, Bremerhaven;CAS slide 220056, California Academy of Sciences,
San Francisco; slide KS0104, The Herbarium,
University of Gent (GENT).
T : Lonely Tarn, Tasmania, Australia.
A. muylaertii can easily be recognized in LM by its
pronounced clavate valve shape with medial apical
point. The valve is strongly asymmetrical about the
apical plane not only because of its semi-arcuate
shape, but also because the ventral bulge of the
headpole is more distally placed than the dorsal
bulge. Strongly heteropolar Actinella species were
also reported (as A. brasiliensis) by Carter & Denny
(1987, p1. 1, fig. 5) from Sierra Leone but their
illustration shows a specimen with a dorsal and
ventral apex. The true identity of their specimens
needs to be investigated. The sternum is narrow but
rather distinct (even in LM, Figs 57–61) in com-
parison with the other newly described Actinella
species. Spines were not observed but a siliceous
ridge was present in some specimens (Figs 52–54).
The helictoglossae are relatively small (again in
comparison with the other species described; Figs
48–50) ; the raphe is sometimes very short (Fig. 49).
Small, sessile rimoportulae were hitherto only
observed in the footpole (Figs 46–48) ; within a
frustule, the rimoportulae of the two valves thus lie
at the same pole (Fig. 47). The copulae are strongly
curved near the headpole. They have, in addition to
one distinct advalvar row of puncta, several other
rows of puncta (Figs 47, 51–53).
Actinella muylaertii was previously illustrated as
Actinella sp. 1 (partim) in Vyverman et al. (1995, pl.
21, fig. 12).
D : Actinella muylaertii was found in
four Tasmanian lakes (the corridor lakes Reservoir
1 and 2, and the western lakes L. Picone and Lonely
Tarn).
Actinella parva K. Vanhoutte & K. Sabbe, sp. nov.
Figs 62–78
Cellulae leviter clavatae aspectu cincturae, 11±0–30±6(17±5³4±6) µm longae. Structura chromato-phororum incognita. Valvae leviter semi-arcuatae
et heteropolares, margine ventrali plus minusve
concave et margine dorsali convexa, 1±5–2±3(2±0³0±2) µm latae in media parte. Capitus-polus1±0–1±6 (1±3³0±2) µm latus, non tumescens. Basis0±9–1±2 (1.0³0±1) µm lata, non tumescens. Striae19–22 (20±4³0±8) in 10 µm, ad centrum parallelae,apices versus radiatae. Areolae parvae, circulares ;
structura velorum incognita (possibiliter erosa).
Sternum angustum et indistinctum. Raphe brevis
magnopere in limbo valvarum sita ; apices distales
earum in facie valvarum flexi. Helictoglossae
distinctae, in latere ventrali valvae positae semper
manifestae. Rimoportula una, ad laterem ventralem
basis vel capiti-poli posita, in transitione faciei
valvarum limbo; in frustulo completo rimoportulae
valvarum semper ad polos oppositos positae.
Cingulum probabiliter ex 4 copulis apertis porosis
constans.
Cells slightly clavate in girdle view, 11±0–30±6(17±5³4±6) µm long. Plastid structure unknown.Valves slightly semi-arcuate and heteropolar, with
ventral margin concave and dorsal margin convex,
1±5–2±3 (2±0³0±2) µm wide at midpoint. Headpole1±0–1±6 (1±3³0±2) µm wide, not tumescent. Footpole0±9–1±2 (1±0³0±1) µm wide, not tumescent. Striae19–22 (20±4³0±8) in 10 µm, parallel in the centre toradiate at the poles. Areolae small, circular ; velum
structure unknown (possibly eroded). Sternum nar-
row and indistinct. Raphe short, largely situated on
the valve mantle ; distal ends bent onto the valve
face. Helictoglossae distinct, clearly visible on the
ventral side of the valve. Rimoportula one per
valve, lying on the ventral side of the foot- or
headpole on the valve face}mantle transition; in acomplete frustule, the rimoportulae of the two
valves always lie at opposite poles. Cingulum
probably composed of 4 open, porous copulae.
H : BM slide 100925, The Natural History
Museum, Department of Botany, London.
I : BRM slide Zu5139 Friedrich Hustedt-
Arbeitsplatz fu$ r Diatomeenkunde, Bremerhaven;CAS slide 220057, California Academy of Sciences,
San Francisco; slide KS0105, The Herbarium,
University of Gent (GENT).
T : Clarence Lagoon, Tasmania,
Australia.
This small Actinella species is rather reminiscent of
Actinella indistincta (cf. above) but has a signifi-
cantly lower stria density. A. parva is only slightly
heteropolar, both in girdle and valve view (Figs
69–78). No distinct sternum can be distinguished
(cf. Fig. 63). The sessile rimoportulae are situated
on the valve face}mantle transition (Figs 64, 67, 68).The copulae are open and slightly curved near the
apices (Figs 62, 64, 65) ; apart from one advalvar
longitudinal row of puncta, a single additional row
is present in the middle of the copula (Figs 62, 64).
Actinella parva was previously illustrated as
Actinella sp. 1 (partim) in Vyverman et al. (1995, p1.
5, figs 6, 8).
D : Actinella parva is common and
widely distributed in the western and corridor lakes
in the Tasmanian highlands but is absent from the
eastern lakes. It has not been found outside
Tasmania.
Dow
nloa
ded
by [
193.
191.
134.
1] a
t 23:
52 1
6 Ja
nuar
y 20
12
332New Actinella spp. from Australasia
Figs 62–78. SEM (Figs 62–68, 78) and light (Figs 69–77) micrographs of Actinella parva from Clarence Lagoon (Tasmania,
holotype population, Figs 62, 64–68, 72–76), Lake Vera (Tasmania, Fig. 63), Lonely Tarn (Tasmania, Fig. 69) and Lake
Rolleston (Tasmania, Figs 70, 71). Fig 62. External girdle view showing cingulum structure and diagonally opposed
rimoportula openings (arrowed). Fig. 63. External, oblique valve view. The rimoportula opening at the headpole is
arrowed. Fig. 64. External girdle and internal valve view, showing the rimoportula at the footpole. Note the rows of puncta
on the valvocopula. Fig. 65. External valve and girdle view. Arrowhead indicates the rimoportula opening at the headpole.
Figs 66–68. Internal valve view (Fig. 68) and details of head- and footpole (Figs 66 and 67 respectively) showing the
rimoportula at the foot pole (arrowheads in Figs 67 and 68). Fig. 69. Girdle view. Figs 70–78. Valve views showing the
range in size and shape. Scale bars represent : 10 µm (Figs 65, 69–77) and 1 µm (Figs 62–64, 66–68, 78). Scale bar for Figs
70–77 is shown in Fig. 69.
Actinella pulchella K. Sabbe & D. Hodgson, sp.
nov.
Figs 1, 79–100
Cellulae clavatae aspectu cincturae, 22±5–70±0(48±9³11±7) µm longae (n¯ 42). Chromatophoraduo, elongata, ad valvas appressa. Valvae clavatae,
semi-arcuatae, margine ventrali concava et margine
dorsali convexa, 1±5–3±5 (2±6³0±4) µm latae in me-dia parte. Capitus-polus 2±1–5±6 (3±4³0±8) µm latus,leviter tumescens in latere ventrali, sub-rostratus ad
rostratum. Basis 1±0–2±2 (1±6³0±3) µm lata, nontumescens, rotundata. Striae punctatae, 18–23
(20±1³1±2) in 10 µm, ad centrum parallelae, apices
Dow
nloa
ded
by [
193.
191.
134.
1] a
t 23:
52 1
6 Ja
nuar
y 20
12
K. Sabbe et al. 333
Figs 79–100. SEM (Figs 79–86) and light (Figs 87–100) micrographs of Actinella pulchella from different localities. Figs
80–82, 85, 86, 87–91, 94, 96, 97, Lake Crater, Tasmania (holotype population) ; Figs 79, 83, 84, 98, 99, Lake Spicer,
Tasmania; Fig. 93, Lake Rhona, Tasmania; Figs 95, 100, Reservoir 2, Tasmania; Fig. 99, Lake Rolleston, Tasmania; Fig.
92, Stewart Island, New Zealand. Fig. 79. External dorsal view of girdle and headpole. Note the longitudinal rows of
puncta on the copulae and the distinct subapical spines on the headpole. Fig. 80. External valve view showing rimoportula
opening at the footpole (arrowhead). Fig. 81. External view of the headpole. Note the small marginal spines along the
dorsal valve margin. Fig. 82. External girdle view of the headpole. Fig. 83. Internal footpole view showing the helictoglossa
and the rimoportula (arrowhead). Fig. 84. Internal valve view. Fig. 85. Internal headpole view with helictoglossa and small
rimoportula (arrowed). Fig. 86. External foot pole view showing the rimoportula opening (arrow). Figs 87–95. Valve views
showing variation in shape and size. Fig. 96. Valve and girdle view of headpole of a single frustule. Fig. 97. Footpole of the
same frustule as in Fig. 96, at different focus. Fig. 98. Girdle view of head pole showing valve with and without subapical
spine. Fig. 99. Girdle view. Fig. 100. Girdle view of recently divided cell. Scale bars represent : 10 µm (Figs 84, 87–100) and
1 µm (Figs 79–83, 85, 86). Scale bar for Figs 88–97, 99–100 is shown in Fig. 87.
versus leviter radiatae. Areolae parvae, circulares ;
structura velorum incognita (possibiliter erosa).
Spina distincta subapicalis ad capito-polo saepe
praesens. Margo valvae spinulis plerumque
praedita. Sternum nullum vel angustum et indis-
tinctum. Raphe brevis magnopere in limbo
Dow
nloa
ded
by [
193.
191.
134.
1] a
t 23:
52 1
6 Ja
nuar
y 20
12
334New Actinella spp. from Australasia
Figs 101–114. SEM and light micrographs of Actinella spp. Figs 101–105. SEM (Figs 101, 102) and light (Figs 103–105)
micrographs of Actinella tasmaniensis from Lake Spicer (Tasmania). Figs 106–113. Light micrographs of Actinella
brasiliensis from Iganape (Donkin 2523, Surinam). Fig. 114. SEM micrograph of Actinella punctata from an unnamed lake
on Mount Giluwe (Papua New Guinea), showing the rimoportula (arrowhead) at the headpole. Figs 101, 102. Internal view
of the headpole and footpole of a single valve. The rimoportulae are arrowed. Fig. 103. Valve view. Note the position of
the raphe on the valve face margin. Figs 104, 105. Details of headpole and footpole of a single valve. The rimoportulae
have been arrowed. Figs 106, 108. Valve views. Figs 107, 109. Girdle views. Detail of footpole in Fig. 109 shows the two
helictoglossae and the rimoportula in the valve on the right (arrowhead). Figs 110, 111. Details of headpole at two different
foci showing the stria pattern and the rimoportula (arrowhead in Fig. 111). Figs 112, 113. Details of footpole of the same
valve as in Figs 110 and 111 at two different foci showing the raphe fissure and the stria pattern (Fig. 113). Fig. 114.
Internal view of the headpole showing the position of the raphe and helictoglossa, and the rimoportula (arrowhead).
valvarum sita ; apices distales earum in facie
valvarum flexi. Helictoglossae distinctae, in latere
ventrali valvae positae semper manifestae. Rimo-
portula probabiliter una, ad laterem ventralem basis
posita, sed nonnumquam quoque in parte apicali
capiti-poli. Cingulum ex 4 copulis apertis ligulatis
porosis constans.
Cells clavate in girdle view, 22±5–70±0(48±9³11±7) µm long (n¯ 42). Plastids two,elongate, valve-appressed. Valves clavate, semi-
Dow
nloa
ded
by [
193.
191.
134.
1] a
t 23:
52 1
6 Ja
nuar
y 20
12
K. Sabbe et al. 335
arcuate, with ventral margin concave and dorsal
margin convex, 1±5–3±5 (2±6³0±4) µm wide at mid-point. Headpole 2±1–5±6 (3±4³0±8) µm wide, slightlybulged on the ventral side, sub-rostrate to rostrate.
Footpole 1±0–2±2 (1±6³0±3) µm wide, not tumescent,rounded. Striae punctate, 18–23 (20±1³1±2) in10 µm, parallel in the centre to slightly radiate at the
poles. Velum structure unknown (possibly eroded).
A distinct, subapical spine is often present on the
headpole. Small spines are usually present along the
valve margin. Sternum absent or narrow and
indistinct. Raphe short, largely situated on the valve
mantle ; distal ends bent onto the valve face.
Helictoglossae distinct, clearly visible on the ventral
side of the valve. Rimoportula probably one per
valve, lying on the ventral side of the footpole, but
sometimes also in the apical part of the headpole.
Cingulum composed of 4 open, ligulate, porous
copulae.
H : BM slide 100926, The Natural History
Museum, Department of Botany, London.
I : BRM slide Zu5}40 Friedrich Hustedt-Arbeitsplatz fu$ r Diatomeenkunde, Bremerhaven;CAS slide 22058, California Academy of Sciences,
San Francisco; slide KS0106, The Herbarium,
University of Gent (GENT).
T : Crater Lake, Tasmania, Australia.
A. pulchella was previously illustrated as Actinella
sp. 1 (partim) in Vyverman et al. (1995, pl. 4, figs
9–10, pl. 5, figs 1–5, 7, pl. 21, figs 4–9). It has two
elongate, often curled, plastids which lie below the
valves (Fig. 1) and which are characterized by two
small round structures (pyrenoids?) near the centre
of the cell. Typically, the valves are slightly tu-
mescent on the ventral side of the headpole (Figs
87–91, 93–96), although the dorsal side can be
tumescent as well (Fig. 88) ; the valves from New
Zealand have a more pronounced tumescence at the
headpole (Fig. 92). The significance of this ob-
servation needs to be assessed (cf. also A.
aotearoaia). Many valves belonging to A. pulchella
are characterized by a distinct subapical spine (Figs
79–82, 96, 98–100) which can best be observed in
girdle view. Some valves lacked this spine, even
when the other valve within the frustule did possess
one (Fig. 98). Small marginal spines are present
along the valve face margin, though not in all
specimens (compare Figs 79, 81 and 82 with Fig.
80). The round areolae are occluded by vela but
their exact nature is unknown (Fig. 82). The sternum
is indistinguishable, even in SEM. Most rimo-
portulae were observed in the footpole (Figs 80, 83,
86) but occasionally also in the apex of the headpole
(Fig. 85). The areolae on the footpole are randomly
scattered and thus almost resemble an apical pore
field (Fig. 86). The cingulum is composed of 4 open,
curved copulae which have several longitudinal
rows of puncta each (Figs 79, 81, 82, 100).
Actinella pulchella is quite reminiscent of A.
brasiliensis (De Oliveira & Steinitz-Kannan, 1992;
de Souza & Moreira-Filho, 1999; Metzeltin &
Lange-Bertalot, 1998; Van Heurck, 1881). A.
brasiliensis specimens from Surinam (AWH slides
VIII 37 B 6 and IX 61 A 4, figs 106–113) correspond
well to the original description of this species in Van
Heurck (1881) and the illustrations in Schmidt’s
Atlas (Schmidt et al., 1874–1959). In the original
description, Actinella brasiliensis is 39–113 µm long,
7±3–9±2 µm wide at the headpole and 2±5–3±3 µm atthe footpole, and has 14–16 striae in 10 µm.
Specimens illustrated in Schmidt’s Atlas and the
ones from Surinam (Figs 106–113) correspond fully
to this size range except for stria density which can
be higher (up to 19 striae in 10 µm). The apical point
is dorsal (Figs 106, 108, 110, 111), rarely medial (in
the smaller specimens; cf. Van Heurck 1881, pl.
XXXV, fig. 19). A rimoportula is present at the
head or footpole (Figs 109 and 111 respectively) ;
note that a footpole rimoportula is only present in
one valve of the frustule shown in Fig. 109. A.
pulchella has a significantly narrower headpole and
higher stria density than A. brasiliensis. A large
subapical spine was never observed in A. brasiliensis
(cf. also Metzeltin & Lange-Bertalot, 1998).
D : Actinella pulchella is the most com-
mon and widespread Actinella species in Tasmania,
but like the other Tasmanian species it is absent
from the eastern lakes. Valves belonging to this
species were also observed in samples from Stewart
Island (New Zealand, Fig. 92).
Actinella punctata Lewis
Fig. 114
D : See Kociolek et al. (1997).
D : A. punctata has hitherto only been
reported from North America and Scandinavia
(Kociolek et al., 1997). In the present study, a few,
usually broken valves belonging to this species were
found in the same oligotrophic highland tarns of
Mount Giluwe (Papua New Guinea) as A.
giluwensis. This constitutes the first confirmed re-
cord of this species for the Southern Hemisphere
and outside North America and Europe.
Actinella tasmaniensis Hustedt
Figs 101–105
D : See Hustedt (1952).
Dow
nloa
ded
by [
193.
191.
134.
1] a
t 23:
52 1
6 Ja
nuar
y 20
12
336New Actinella spp. from Australasia
This species had hitherto only been observed in LM
(Simonsen, 1987; Vyverman et al., 1995). SEM
observations (Figs 101, 102) confirm the presence of
two rimoportulae per valve, one just below the
footpole helictoglossa and one in the apex of the
headpole. These rimoportulae are also visible in LM
(Figs 104, 105). Note the position of the raphe,
which runs alongside the valve face}mantle marginand which is clearly visible in valve view (Fig. 103).
Observations on live material revealed that A.
tasmaniensis, like A. punctata (Lewis 1863), forms
small stellate colonies on diverse submerged sub-
strata.
Discussion
All the above-described species are more or less
heteropolar, both in valve and in girdle view, have a
simple raphe structure and possess rimoportulae.
They have therefore been assigned to the genus
Actinella (Round et al., 1990). To our knowledge,
plastid structure has not been documented before in
this genus. Our observations on live A. aotearoaia
and A. pulchella show that the organization and
structure of the plastids is similar to that of Eunotia,
i.e. there are two elongate, valve-appressed plastids
per valve.
The validity of the genera Actinella and Desmo-
gonium with respect to Eunotia has been under
dispute for a long time (Hustedt, 1949; Cholnoky,
1954; Patrick & Reimer, 1966; Metzeltin & Lange-
Bertalot, 1998). Both Eunotia and Desmogonium
were described by Ehrenberg (1837 and 1848 re-
spectively) and neither of the (concise) type
descriptions contains direct reference to the features
which are nowadays considered to be characteristic
for these genera (such as the simple raphe structure
or the presence of rimoportulae; cf. above and
Round et al., 1990). The main distinction between
these two genera in the protologues concerns the
type of colony formation in Desmogonium (‘Lorica
(…) bacillaris (nec cuneata nec lanceolata)
fasciculatim in series ramosas dichotomas evoluta,
arbusculam referens’ – Frustule (…) rod-shaped
(not cuneate nor lanceolate) fasciculately developed
in dichotomously branched series, reminiscent of a
small tree ’ ; Ehrenberg, 1848). All other distin-
guishing characteristics have been added a
posteriori. According to the generic circumscription
of Patrick & Reimer (1966), Desmogonium thus
differs from Eunotia in the possession of spines
along both the ventral and dorsal valve margins and
its colony growth form, which they describe as
‘zigzag’. They also point out that usually two
rimoportulae (‘ jelly pores ’) are visible at both ends
of the valve in Desmogonium (in Eunotia there is
mostly one rimoportula per valve; Vyverman et al.,
1998). Metzeltin & Lange-Bertalot (1998) argue
that the main discriminating morphological features
of Desmogonium and Eunotia are insufficient for
separation at the genus level and formally propose a
rank alteration for Desmogonium to become a
subgenus of Eunotia. However, we believe that,
given the fact that no thorough studies have yet
been made of their types (D. guinanense Ehrenberg
and E. arcus Ehrenberg), the two genera should be
kept separate.
Metzeltin & Lange-Bertalot (1998) hold the
opinion that Actinella should also be reduced to the
rank of subgenus (of Eunotia) because hetero-
polarity would exist in Eunotia and isopolarity in
Actinella (cf. also Cholnoky, 1954). However, they
do not propose a formal recombination as, ac-
cording to the authors, this would involve the
creation of a large number of synonyms (actually
only 36; cf. Table 1). Little is known about the
taxonomic value of heteropolarity versus iso-
polarity in diatoms. Asymmetry about the trans-
apical and pervalvar axes is predominantly found in
taxa that are attached to a substratumvia amucilage
stalk and especially when the cells grow close
together in stellate or fan-shaped colonies.
Examples include the araphid genera Licmophora
Agardh, Meridion Agardh and Distrionella
Williams but also raphid genera such as
Rhoicosphenia Grunow, Gomphonema Ehrenberg
and Didymosphenia Schmidt (cf. Williams, 1990;
Round et al., 1990). The fact that a common life
form is found in phylogenetically distant groups
(both araphid and raphid lineages) suggests that it
has arisen on several occasions. This is in accord-
ance with the results of cladistic analyses based on
morphological and cytoplasmic features which have
shown that heteropolarity is a convergent feature,
within both the araphid (Williams, 1990) and the
raphid groups (Kociolek & Stoermer, 1986, 1988)
investigated. Moreover, heteropolarity is con-
sidered to be an autapomorphic feature at the genus
level in the above-mentioned raphid and araphid
taxa (the single isopolar Meridion species (Williams,
1985) should be placed in a separate genus according
to Williams (1997)). By analogy with heteropolarity,
Mann & Stickle (1997) concluded that dorsi-
ventrality (i.e. amphoroid symmetry) has sporadi-
cally evolved in different raphid, benthic diatom
groups in taxa living on sandy and rocky substrata.
Both features therefore appear to be an adaptation
to a specific life form.
In Actinella, heteropolarity is also obligatory for
membership of the genus. A. punctata, the type of
the genus, is characterized by heteropolar valves,
both in valve and girdle view (Lewis, 1863; Kociolek
et al., 1997). Heteropolarity in girdle view appears
to be the case for most Actinella species (e.g. this
study; Moser et al., 1998), although it is unfortu-
nately often not illustrated (e.g. Van Heurck, 1881;
Dow
nloa
ded
by [
193.
191.
134.
1] a
t 23:
52 1
6 Ja
nuar
y 20
12
K. Sabbe et al. 337
Hustedt, 1952), even in recent papers (da Costa
1995; Moser et al., 1998; Metzeltin & Lange-
Bertalot, 1998). Eunotia species are always rec-
tangular or trapezial (e.g. Krammer & Lange-
Bertalot, 1991, t. 164, figs 10, 11) in girdle view (the
latter shape can also be observed in Eunophora ;
Vyverman et al., 1998). To date, group membership
of Eunotia and Actinella has been exclusively based
on cell polarity, except when the author considered
them congeneric. For example, the strongly hetero-
polar diatom Eunotia actinelloides Cholnoky (prob-
ably synonymous with Eunotia asymmetrica
Cholnoky (Cholnoky, 1954)) was explicitly
described as a Eunotia species because Cholnoky
held the opinion that the two genera would be
merged sooner or later (note that E. actinelloides
was later transferred to Actinella (A. cholnokii),
although nothing is as yet known about the sym-
metry of the frustule in girdle view). The remainder
of heteropolar Eunotia species (e.g. E. cuneiformis
Manguin, E. raytonensis Cholnoky, E. fallax var.
aequalis Hustedt, E. tenella var. capensis Cholnoky)
all belong to the species cluster around Eunotia
rhomboidea Hustedt and might even be conspecific
with it (cf. Coste & Ricard, 1982; Krammer &
Lange-Bertalot, 1991). E. rhomboidea valves can be
both iso- or heteropolar ; in girdle view, however,
they are rectangular or rhombic. The morphology
and exact taxonomic position of this species (or
species group) requires further investigation. On the
whole, valve heteropolarity in Eunotia cells is the
exception rather than the rule (cf. the Eunotia plates
in e.g. Krammer & Lange-Bertalot, 1991 and
Metzeltin & Lange-Bertalot, 1998: not a single
heteropolar valve). At present, we believe that the
distinction between Eunotia and Actinella on the
basis of cell symmetry (both in girdle and valve
view) can be maintained. In addition, rimoportula
number and position appears to be more variable
within Actinella than in Eunotia (see below). Further
studies, incorporating reproductive and molecular
information, are necessary to resolve phylogenetic
relationships within the Eunotiophycidae.
Cultria Metzeltin & Lange-Bertalot, the newly
described heteropolar subgenus of the genus
Eunotia, differs from Actinella only in the presence
of a ‘basal plateau’ at the footpole (Metzeltin &
Lange-Bertalot, 1998). Whether or not Cultria, like
Actinella, is also heteropolar in girdle view is not
mentioned in the protologue of Cultria and cannot
be seen in the illustrations provided. The absence of
spines in Cultria is not a good diagnostic feature as
this seems to be variable within Actinella (e.g. spines
are facultative in A. pulchella ; Figs 79–82). We
therefore see no reason to distinguish between
Actinella and Cultria on the basis of a single feature,
viz. the basal plateau, as repeatedly advocated by
the authors themselves (e.g. Lange-Bertalot, 1997).
Species distinction within the genus Actinella is
mainly based on cell dimensions, shape, stria den-
sity, presence and position of rimoportulae, and
growth form. In the two largest species, A.
tasmaniensis (cf. also Hustedt, 1952) and A.
giluwensis (Figs 22, 26), there are two rimoportulae
per valve, as in the type species A. punctata (Round
et al., 1990). In A. brasiliensis, some valves have two
rimoportulae, but most valves have only one rimo-
portula. In A. aotearoaia, A. indistincta and A. parva
there is one rimoportula per valve, either at the
head- or footpole; within a frustule, they are
diagonally opposite. This was also observed in A.
guinanensis (Metzeltin & Lange-Bertalot, 1998) and
is also the case in most Eunotia species (Vyverman et
al., 1998). Finally, in Actinella muylaertii, rimo-
portulae may be present at both footpoles within a
frustule (Fig. 47). It thus appears that rimoportula
number and position is rather variable in Actinella,
as in Eunophora (Vyverman et al., 1998), but unlike
in Eunotia, Peronia and Desmogonium, where this is
a more constant generic feature (Round et al.,
1990).
All newly described Actinella species were found
in dystrophic to (ultra-)oligotrophic waters, where
they can be a dominant component of the litoral
diatom assemblages (e.g. A. parva up to 41% in
Lake Spicer, Tasmania; Vyverman et al., 1996).
With the exception of A. tasmaniensis, all species in
Tasmania are predominantly confined to the humic
western lakes, characterized by low pH (! 5) andan ion composition close to that of seawater (Tyler,
1992; Vyverman et al., 1996). In the anthro-
pogenically acidified Owen Tarn (Tasmania), A.
pulchella is the dominant species (up to 40% relative
abundance) in the top layers of the sediments
(inferred pH in these layers is approximately 4±2;Hodgson et al., 2000), suggesting a high tolerance
of acidity. A. tasmaniensis is largely confined to
oligotrophic lakes but also occurs in more humic
conditions. Scattered observations on live material
of some species (A. aotearoaia, A. tasmaniensis and
A. pulchella) revealed that they live attached to
various types of substrata, ranging from flocculent
detrital matter, and mucous biofilms on submerged
rocks to mosses and macroalgae.
The geographical distribution patterns of the
species within the genus Actinella raise some
interesting biogeographical questions, as there ap-
pear to be large differences in geographic range
amongst species (Table 1). Only two species, A.
brasiliensis and A. punctata, have a worldwide
distribution. A. brasiliensis is common and wide-
spread in the Amazon basin (South America; e.g.
Van Heurck, 1881; De Oliveira & Steinitz-Kannan,
1992; Metzeltin & Lange-Bertalot, 1998) but has
also been reported from Japan (e.g. Okuno, 1964).
The West African reports by Carter & Denny (1982)
Dow
nloa
ded
by [
193.
191.
134.
1] a
t 23:
52 1
6 Ja
nuar
y 20
12
338New Actinella spp. from Australasia
and numerous other records, mainly from Asia
(Russia, e.g. Skortzow, 1929) but also from
Australia (Foged, 1979), need to be verified. A.
punctata is known from North America and
Scandinavia (Kociolek et al., 1997) and Papua New
Guinea (this study). All other Actinella species have
more limited distributions. It is striking that the
Southern Hemisphere regions are strongholds for
species diversity in this genus (which disproves the
statement in Round et al. (1990) that the genus is
mainly tropical in distribution) and that each major
biogeographical region has its own endemic species.
At least 9 Actinella species are endemic to
Australasia (Table 1). Even at smaller spatial scales
within this region, there are marked differences in
geographic range: some species occur over a wide
range (e.g. A. aotearoaia : New Zealand, Tasmania
and the Australian mainland), others have more
limited ranges (e.g. A. indistincta and A. pulchella :
Tasmania and New Zealand), while still others are
known from a few lakes only (A. giluwensis and A.
muylaertii). These findings are in accordance with
recent studies which indicate that endemism in
diatoms (but also in other microalgal groups such as
Chlorophyta and Chrysophyta) might be more
widespread than previously thought (cf. Mann &
Droop, 1996; Tyler, 1996; Williams, 1996; Passy et
al., 1997; Spaulding & Kociolek, 1998; Spaulding et
al., 1999). This is especially true for the Australasian
region (Vyverman, 1988; Vyverman et al., 1997;
1998; Moser et al., 1998; Moser, 1999; Sabbe et al.,
2000). However, studies on groups such as ciliates
(Esteban et al., 2000), heterotrophic chrysophytes
(Finlay & Clarke, 1999) and heterotrophic
flagellates (Patterson, 1999) emphasize that protists
in general are ubiquitous and that community
composition is predominantly determined by habi-
tat type. In the opinion of these authors, extrinsic
factors such as undersampling of rare habitats but
also of rare taxa or resting stages lead to erroneous
claims of endemism. This would mean that the
dilute, humic lakes in the alpine regions of Tasmania
and the south Island of New Zealand, which are
a major stronghold of endemic diatoms (cf.
Vyverman et al., 1997, 1998; this study), constitute
unique environments on a worldwide scale, and that
the so-called endemics are simply rare (i.e. restricted
to a rare habitat) but not truly endemic. However,
lakes with similar limnological characteristics exist
in other, better-studied parts of the world (e.g.
Henriksen et al., 1998), and, as many of the endemic
diatoms have very distinct morphological features,
it is unlikely that they would have been overlooked.
We therefore believe that they are true endemics,
and that factors other than habitat rarity have
played a role in creating restricted distributions.
The case of the genus Actinella, with large inter-
specific differences in geographic ranges, shows that
this hypothesis does not have to contradict the
findings from other, possibly truly ubiquitous
protist groups. It does, however, indicate that
caution is called for when extrapolating results from
one taxonomic group (or even taxon) to the other.
Finally, how and to what degree climatic, geo-
logical, biological and ecological processes influence
there biogeographical patterns is still largely un-
known. Studies on the possible impact of such
diverse phenomena as plate tectonics (Coleman,
1996), dispersal capacities and evolutionary age
(Coleman et al., 1994; Theriot, 1992) and human
activities (such as introductions, cf. Harper, 1994;
Edlund et al., 2000; or extinctions, cf. Julius et al.,
1998) on microalgal distributions indicate, however,
that there is probably more to protist biogeography
than a simple ‘everything is everywhere ’.
Acknowledgements
K.S. is a Senior Research Fellow with the Fund for
Scientific Research (FWO, Belgium). Financial
support for W.V. and K.S. was provided by FKFO
project no. G.0024.96. We gratefully acknowledge
the support of the National Science Foundation
(grant g INT-9417225 and INT-9908522) forR.L.L. and a Graduate Fellowship for S.N.F. The
New Zealand Foundation for Research Science and
Technology provided funding for E. Bergey (con-
tract 1820, Biodiversity of Freshwater Organisms)
and B. Biggs (contract 1519, Environmental Hy-
drology and Habitat Hydraulics). Dr G. Van
Steenbergen of the Royal Society of Zoology
(Antwerp) is thanked for the loan of the Van Heurck
collection slides. We are greatly indebted to Dr
Hallegraeff and colleagues (Botany Department,
University of Tasmania) for the use of their micro-
scopical facilities and Dr Kociolek for advice on
parts of the manuscript. Drs P. Compe' re (NationalBotanic Garden, Brussels), R. Jahn (Botanisches
Garten und Botanisches Museum, Berlin) and D.
Lazarus (Museum fu$ r Naturkunde, Humboldt Uni-versity, Berlin) are thanked for help with the
translation and understanding of the Ehrenberg
manuscripts. Many thanks are also due to Dr Cathy
Kilroy and Dr John Ferris for the collection of
diatom samples from remote sites in New Zealand
and Australia. Dr P. Tyler (Deakin University) is
thanked for logistical support and inspiring dis-
cussions on Tasmanian freshwater algae.
References
A (1975). Proposals for a standardization of diatom
terminology and diagnoses. Nova Hedwigia, Beih., 53 : 323–354.
B, P. & M, E. (1949). Contribution a' l’e! tude de laflore algale d’eau douce de Madagascar : le Lac Tsimbazaza.
MeUm. l ’Inst. Sci. Madagascar, SeU r. B., 2 : 161–190.B, J. (1896). Diatome! es mioce' nes: espe' ces nouvelles. Le
Diatomiste, 2 : 229–247.
Dow
nloa
ded
by [
193.
191.
134.
1] a
t 23:
52 1
6 Ja
nuar
y 20
12
K. Sabbe et al. 339
C, J.R. & D, P. (1982). Freshwater algae of Sierra Leone.
III. Bacillariophyceae. Nova Hedwigia, Beih., 73 : 281–331.
C, J.R. & D, P. (1987). Freshwater algae of Sierra Leone.
IV. Bacillariophyceae. Part (ii) : Diatoms from the coastal region
of the southern province. Nova Hedwigia, 44 : 229–275.
C, B.J. (1954a). Diatomeen und einige andere Algen aus
dem ‘deHoek’-reservat in Nord-Transvaal. Bot.Not., 3 : 269–296.
C, B.J. (1954b). Ein Beitrag zur Kenntnis der Algenflora
des Mogol-Flusses in Nord-Ost Transvaal. Or st. Bot. Zeitschr.,101 : 118–139.
C, B.J. (1955). Hydrobiologische Untersuchungen in
Transvaal. I. Vergleichung der herbstlichen Algengemeinschaften
in Rayton-vlei und Leeufontein. Hydrobiologia, 7 : 137–209.
C, A.W. (1996). The Indian connection, crucial to re-
construction of the historical biogeography of freshwater algae:
examples among Volvoceae (Chlorophyta). NovaHedwigia, Beih.,
112 : 477–482.
C, A.W., S, A. & G, L.J. (1994). Molecular
delineation of species and syngens in Volvocacean green algae
(Chlorophyta). J. Phycol., 30 : 80–90.
C, M. & R, M. (1982). Contribution a' l’e! tude desdiatome! es d’eau douce des Seychelles et de L’Ile Maurice.Cryptogamie, Algol., 3 : 279–131.
C, E.J. & R, R. (1980). The striae of pennate diatoms. In
Proceedings of the Sixth Symposium on Recent and Fossil Diatoms
(Ross, R., editor), 267–278. Otto Koeltz, Koenigstein.
D C, J.C.F. (1995). Diatoma! ceas (Bacillariophyceae) daReserva Biolo! gica de poc: o das Antas, municı!pio de Silva Jardim,Rio de Janeiro, Brasil. Iheringia, Ser. Bot., 46 : 57–143.
D O, P.E. & S-K, M. (1992). The diatom
flora (Bacillariophyceae) of the Cuyabeno Faunistic Reserve,
Ecuadorian Amazonia. Nova Hedwigia, 54 : 515–552.
D S, M.G.M. & M-F, H. (1999). Diatoms
(Bacillariophyceae) from two aquatic macrophyte banks from
Lagoa Bonita, Distrito Federal, Brazil. I. Thalassiosiraceae and
Eunotiaceae. Bull. Natl. Plant. Belg., 67 : 259–278.
E, M.B., T, C.M., S, C.L. & S, E.F.
(2000). Thalassiosira baltica (Grunow) Ostenfeld (Bacillario-
phyta), a new exotic species in the Great Lakes. Can. J. Fish.
Aquat. Sci., 57 : 610–615.
E, C.G. (1837). U> ber ein aus fossilen Infusorienbestehendes, 1832 zu Brod verbacknes Bergmehl von den Grenzen
Lapplands in Schweden. Bericht uX ber die zur Bekanntmachunggeeigneten Verhandlunger der KoX nigl. preuss. Akademie derWissenschaften zu Berlin : 43–45.
E, C.G. (1848). Die Mikroskopischen Lebensformen. In
Reisen in Britisch-Guiana in den Jahren 1840–1844, Part 3
(Schomburgk, R., editor), 537–544. J.J. Weber, Leipzig.
E, G.F., F, B.J., O, J.L. & T, P.A. (2000).
Ciliated protozoa from a volcanic crater-lake in Victoria,
Australia. J. Nat. Hist., 34 : 159–189.
F, B.J. & C, K.J. (1999). Ubiquitous dispersal of
microbial species. Nature, 400 : 828.
F, C.W. (1917). Su$ ss wasserdiatomeen Ober-Ja$ mtland inSchweden. Ark. Bot., 14 (21) : 1–68.
F, N. (1978). Diatoms in Eastern Australia. Bibl. Phycol., 41 :
1–242.
F, N. (1979). Diatoms in New Zealand, the North Island. Bibl.
Phycol., 47 : 1–224.
H, B.T. & MK, I.D. (1986). Chemical limnology in
Australia. In Limnology in Australia (De Deckker, P. & Williams,
W.D., editors), 3–31. Junk Publishers, Dordrecht.
H, M.A. (1994). Did Europeans introduce Asterionella
formosa Hassall to New Zealand?. In Proceedings of the 11th
International Diatom Symposium (Kociolek, J.P., editor),
479–484. The California Academy of Sciences, San Francisco.
H, I. (1964). An Introductory Account of the Smaller Algae of
British Coastal Waters, part V, Bacillariophyceae (Diatoms).
Her Majesty’s Stationery Office, London.
H, A., S, B.L., M, J., W, A.,
H, R., C, C., J, J.P., F, E. & M,
T. (1998). Northern European Lake Survey, 1995. Finland,
Norway, Sweden, Denmark, Russian Kola, Russian Karela,
Scotland and Wales. Ambio, 27 : 80–91.
H!, F.J. (1902). Les DiatomeU es d ’Auvergne. PremierMeUmoire. Librairie des Sciences naturelles, Paris.
H, D., V, W., C-L, A & T, P.A.
(2000). From rainforest to wasteland in 100 years : the limno-
logical legacy of the Queenstown mines, Western Tasmania.
Arch. Hydrobiol., 149 : 153–176.
H, F. (1949). Su$ sswasser-Diatomeen aus dem Albert-Nationalpark in Belgisch Kongo. Expl. Parc Natl. Albert. Mission
Damas (1935–1936), 8 : 1–199.
H, F. (1952). Neue und wenig bekannte Diatomeen. III.
Phylogenetische Variationen bei den rhaphidioiden Diatomeen.
Ber. Dtsch. Bot. Ges., 65 : 133–144.
H, F. (1965). Neue und wenig bekannte Diatomeen. IX.
Su$ sswasser-Diatomeen aus Brasilien, insbesondere desAmazonasgebietes. Int. Rev. Ges. Hydrobiol., 50 : 391–410.
K, J.P. & R, K. (1998). Raphe vestiges in ‘Asterionella ’
species from Madagascar : evidence for a polyphyletic origin of
the araphid diatoms? Cryptogamie, Algol., 19 : 57–74.
K, J.P. & S, E.F. (1986). Phylogenetic relationships
and classification of monoraphid diatoms based on phenetic and
cladistic methodologies. Phycologia, 25 : 297–303.
K, J.P. & S, E.F. (1988). A preliminary investi-
gation of the phylogenetic relationships among the freshwater,
apical pore field-bearing cymbelloid and gomphonemoid diatoms
(Bacillariophyceae). J. Phycol., 24 : 377–385.
K, J.P., R, K. & W, D.M. (1997). Taxonomy,
ultrastructure and biogeography of the Actinella punctata species
complex (Bacillariophyta: Eunotiaceae). Nova Hedwigia, 65 :
177–193.
K, K. & L-B, H. (1991). Bacillariophyceae.
Part 3. Centrales, Fragilariaceae, Eunotiaceae. In SuX sswasserfloravonMitteleuropa (Ettl,H.,Gerloff, F.,Heynig,H. &Mollenhauer,
D., editors). G. Fisher, Stuttgart.
L-B, H. (1997). As a practical diatomist, how does one
deal with the flood of new names? Diatom, 13 : 9–12.
L, F.W. (1863). On some new and singular intermediate forms
of diatomaceae. Proc. Acad. Nat. Sci. Philad., 15 : 336–346.
M, D.G. & D, S.J.M. (1996). Biodiversity, biogeography
and conservation of diatoms. Hydrobiologia, 336 : 19–32.
M, D.G. & S, A.J. (1997). Sporadic evolution of
dorsiventrality in raphid diatoms, with special reference to Lyrella
amphoroides sp. nov. Nova Hedwigia, 65 : 59–77.
M, D. & L-B, H. (1998). Tropical diatoms of
South America: I. Icon. Diatomol., 5 : 3–695.
M$ , K. (1951). Beitra$ ge zur Kenntnis der rezentenDiatomeenflora Ostkareliens. Ann. Soc. Zool. Bot. Fen. Vanamo,
25 : 1–35.
M, G. (1999). Die Diatomeenflora von Neukaledonien.
Systematik, Geobotanik, O> kologie, ein Fazit. Bibl. Diatomol., 43 :1–205.
M, G., L-B, H. & M, D. (1998). Insel der
Endemiten. Geobotanisches Pha$ nomen Neukaledonien. Bibl.Diatomol., 38 : 1–464.
N, J.L. (1983). A new method using hexamethyldisilazane for
preparation of soft insect tissues for scanning electron
microscopy. Stain Tech., 58 : 347–351.
O, H. (1964). Part V: Fossil diatoms. In Diatomeenschalen im
elektronenmikroskopischen Bild (Helmcke, J.-G. & Krieger, W.,
editors). J. Cramer, Weinheim.
P, S.I., K, J.P. & L, R.L. (1997). Five new
Gomphonema species (Bacillariophyceae) from rivers in South
Africa and Swaziland. J. Phycol., 33 : 455–474.
P, R. & R, C.W. (1966). The diatoms of the United
States, exclusive of Alaska and Hawaii. Vol. 1. Fragilariaceae,
Eunotiaceae, Achnanthaceae, Naviculaceae. Monogr. Acad. Nat.
Sci. Philad., 13 : 1–688.
R, R., C, E.J., K, N.I., M, D.G., P,
T.B.B., S, R. & S, P.A. (1979). An amended ter-
Dow
nloa
ded
by [
193.
191.
134.
1] a
t 23:
52 1
6 Ja
nuar
y 20
12
340New Actinella spp. from Australasia
minology for the siliceous components of the diatom cell. Nova
Hedwigia, Beih., 64 : 513–533.
R, F.E., C, R.M. & M, D.G. (1990). The
Diatoms: Biology and Morphology of the Genera. Cambridge
University Press, Cambridge.
S, K., V, K. &