AN ABNORMAL THORNBACK RAY RAJA CLAVATA WITH ADDITIONAL PECTORAL FINS

31 AN ABNORMAL THORNBACK RAY RAJA CLAVATA

Trans. Suffolk Nat. Soc. 41 (2005)

AN ABNORMAL THORNBACK RAY RAJA CLAVATA WITH ADDITIONAL PECTORAL FINS

J. R. ELLIS

An abnormal thornback ray Raja clavata Linnaeus, 1758 was caught by long line on 9 March 2005 near the Shipwash Bank (south-east of Orford, at approximately 52º 01’N, 01º 39’E). The specimen was an immature male of 54 cm total length (36·5 cm disc width and 27 cm disc length), and weighed approximately 850 g. Two additional fins were present on the dorsal surface, each originating from the mid-line and lying on the right hand side of the fish (Figure 1a). The anterior additional fin was relatively large, and the more posterior additional fin smaller.

The distance between the tip of the snout and the origin of the base of the anterior additional fin was 12 cm, and the origin of the base was 27 mm behind the spiracles. The maximum length and width of the anterior additional

Figure 1: Abnormal thornback ray Raja clavata showing (a) the dorsal surface with the anterior additional fin (A1), posterior additional fin (A2), and (b) x-ray of the specimen showing the upper jaw or palatoquadrate (Pal), lower jaw or Meckel’s cartilage (Mec), pectoral radials (p.r.), branchial arches (Bra), pectoral girdle (Pec), vertebral column (Ver), proterygium (Pro), mesopterygium (Mes) and metapterygium (Met), and with the approximate position of the additional fins marked.

Figure 1a Figure 1b


Suffolk Natural History, Vol. 41 32

Def

orm

ity

Sp

ecie

s L

ength

W

idth

S

ex

Dat

e L

oca

tion

Ref

eren

ce

Th

ree

add

itio

nal

fin

s (6

, 9 a

nd

13

cm

in

le

ng

th)

on

d

ors

al

surf

ace,

sli

gh

tly

to t

he

rig

ht

of

the

mid

-lin

e

Dip

turu

s b

ati

s 8

4 c

m

- M

-

Aber

dee

n

Ren

nie

(1906

)

Ad

dit

ion

al

pec

tora

l fi

n

(9

cm

lon

g)

on

mid

-lin

e, l

yin

g t

o t

he

rig

ht

Dip

turu

s b

ati

s -

- -

- A

ber

dee

n

Ren

nie

(1906

)

Ad

dit

ion

al

pa

ir

of

fin

s as

soci

ated

w

ith

th

e b

ran

chia

l

arch

es a

nd

pec

tora

l g

ird

le o

n t

he

ven

tral

su

rfac

e

Leu

cora

ja c

ircu

lari

s -

47·5

cm

M

-

Nort

h S

ea

Har

per

(1933

)

Ad

dit

ion

al

pa

ir

of

fin

s as

soci

ated

w

ith

th

e b

ran

chia

l

arch

es o

n t

he

ven

tral

su

rfac

e

Leu

cora

ja c

ircu

lari

s 7

5 c

m

46

cm

M

-

NE

Shet

lan

d

Isle

s D

u B

uit

(1978)

Ad

dit

ion

al

fin

on

th

e d

ors

al

surf

ace,

lyin

g t

o t

he

rig

ht

Leu

cora

ja n

aev

us

- -

- -

Cel

tic

Sea

D

u B

uit

(1978)

An

ad

dit

ion

al f

in (

11

cm

hig

h)

on

the

left

w

ing

, cl

ose

to

th

e

scap

ula

Ra

ja c

lava

ta

91 c

m

- F

1845

Norm

andy

Des

long

cham

ps

(1853)

Ad

dit

ion

al

fin

as

soci

ated

w

ith

the

scap

ula

an

d

lyin

g

on

th

e

rig

ht

han

d

sid

e o

f th

e d

ors

al

surf

ace

Ra

ja c

lava

ta

- -

- -

Cel

tic

Sea

D

u B

uit

(1978)

Ta

ble

1:

Det

ail

s of

ska

tes

(Ra

jid

ae)

rec

ord

ed i

n N

ort

h-w

est

Eu

rop

ean

sea

s w

ith

ad

dit

ion

al

fin

s p

rese

nt



Tab

le 1

. C

on

tin

ued

Def

orm

ity

Sp

ecie

s L

ength

W

idth

S

ex

Dat

e L

oca

tion

Ref

eren

ce

Ad

dit

ion

al fi

n ar

isin

g fr

om

th

e

mid

lin

e on

th

e dors

al

surf

ace,

as

soci

ated

wit

h t

he

scap

ula

, an

d

lyin

g t

o t

he

rig

ht

Ra

ja c

lava

ta

- -

- -

- S

chnak

enbec

k

(1942)

Ad

dit

ion

al

fin

(7·5

cm

h

igh

) ly

ing

to t

he

rig

ht

of

the

mid

lin

e R

aja

cla

vata

49 c

m

35 c

m

- -

Co K

erry

H

illi

s (1

966)

Ad

dit

ion

al

fin

on

th

e d

ors

al

mid

lin

e p

ost

erio

r to

th

e h

ead

an

d

lyin

g t

o t

he

left

Ra

ja c

lava

ta

- 4

2 c

m

F

- A

ngle

sey

Gro

ve

and R

ober

ts

(1982)

Ad

dit

ion

al f

in (

2·2

cm

hig

h)

on

th

e d

ors

al

surf

ace

lyin

g

to

the

left

Ra

ja c

lava

ta

16·5

cm

11·1

cm

F

A

pr

1994

Sw

anse

a E

llis

(u

npubli

shed

)

Ad

dit

ion

al f

ins

lyin

g t

o t

he

rig

ht

of

the

mid

-lin

e on

th

e d

ors

al

surf

ace

Ra

ja c

lava

ta

54 c

m

36·5

cm

M

M

ar 2

005

South

ern

Nort

h S

ea

This

stu

dy

Sm

all

(5–6

cm

) ad

dit

ion

al p

ec-

tora

l fi

n

pro

ject

ing

fr

om

th

e

rig

ht

sid

e of

the

pec

tora

l g

ird

le

on t

he

ven

tral

su

rfac

e

Ra

ja m

on

tag

ui

- 2

4 c

m

- Ja

n 1

917

Gre

at O

rme

Johnst

one

(1920)



Sp

ecie

s L

eng

th

Wid

th

Sex

D

ate

Loca

tion

Ref

eren

ce

Pec

tora

l fi

ns

not

fuse

d t

o h

ead

Am

bly

raja

ra

dia

ta

63

cm

-

M

Nov 1

958

New

foundla

nd

Tem

ple

man

(1965)

Leu

cora

ja s

pp.*

-

- M

S

ep 1

909

Aber

dee

n

Wil

liam

son

(1911)

Ra

ja a

steri

as

- -

F

Nov 1

886

- B

ure

au (

18

89)

Ra

ja b

rach

yura

1

2 c

m

8 c

m

- A

pr

1934

Conca

rnea

u

Leg

endre

(1935)

Ra

ja b

rach

yura

4

1·5

cm

-

M

1943

La

Roch

elle

L

etac

onnou

x (

1949)

Ra

ja c

lava

ta

- 1

1 c

m

- S

ep 1

905

Bla

ckp

ool

Johnst

one

(1906)

Ra

ja c

lava

ta

- 6

0 c

m

M

- -

Vai

llan

t (1

908)

Ra

ja c

lava

ta

- 4

7.5

cm

F

-

- W

illi

amso

n (

1911)

Ra

ja c

lava

ta

- 4

6 c

m

F

- -

Wil

liam

son

(1911)

Ra

ja c

lava

ta

- 5

1 c

m

M

Feb

1930

Off

Ply

mouth

F

ord

(1930

)

Ra

ja c

lava

ta

72·8

cm

5

1·4

cm

M

A

ug 1

963

Conca

rnea

u

Du B

uit

(1

964)

Ra

ja c

lava

ta

- -

- -

Conca

rnea

u

Du B

uit

(1

978)

Pec

tora

l fi

ns

not

fuse

d t

o h

ead

(ri

gh

t si

de o

nly

)

Ra

ja m

icro

ocell

ata

-

26

cm

F

Ja

n 1

928

Off

Ply

mouth

F

ord

(1930

) R

aja

ra

du

la

54

cm

3

7 c

m

M

Mar

1975

Gulf

of

Tunis

C

apap

é an

d

Pan

toust

ier

(197

5)

Ro

stro

raja

alb

a

26

cm

1

8·5

cm

-

- A

dri

atic

D

’Anco

na

(1933

)

Pec

tora

l fi

ns

not

fuse

d t

o h

ead

an

d f

lesh

y l

ob

es b

etw

een

an

teri

or

marg

ins

of

pec

tora

l fi

ns

an

d h

ead

* E

ith

er L

. n

aevu

s or

L. fu

llo

nic

a

Ta

ble

2:

Det

ail

s of

ab

norm

al sk

ate

s (R

aji

da

e) w

ith

oth

er d

eform

itie

s of

the

pec

tora

l fi

ns.



fin were 91 mm and 60 mm respectively, and the base of this fin was 28 mm. The posterior additional fin was approximately 10 mm behind the anterior fin. The maximum length and width of the posterior additional fin were 39 mm and 25 mm respectively, and the base of this fin was 17 mm.

Both additional fins were pigmented on both sides, but paler towards the margins, and the skin was spinulose, although smoother nearer the margins. The anterior additional fin had several associated thorns, including median thorns posterior and anterior to the base, a well-developed thorn on the innermost part of the fin, and three spines on the lower posterior margin. The smaller of the additional fins had a median thorn near the base.

Cartilaginous radial elements were present in both additional fins, and were well developed in the more anterior fin. The large size and structure of the anterior fin, including the presence of a well-developed thorn, suggest that this was an additional pectoral fin, and the x-ray of the specimen (Figure 1b) confirmed that this fin was associated with the pectoral girdle. The pectoral girdle on the specimen was not symmetrical, and the connection between the pectoral girdle and metapterygium on the right hand side of the fish was malformed.

There are occasional reports of additional fins in skates (Table 1), including common skate Dipturus batis (Linneus, 1758) (Rennie, 1906), sandy ray Leucoraja circularis (Couch, 1838) (Harper, 1933; Du Buit, 1978), cuckoo ray L. naevus (Müller & Henle, 1841) (Du Buit, 1978), spotted ray Raja montagui Fowler, 1910 (Johnstone, 1920) and R. clavata (Deslongchamps, 1853; Schnakenbeck, 1942; Hillis, 1966; Grove and Roberts, 1982). Interestingly, in the majority of these reports, the additional fin lies on the right hand side of the fish.

Several other forms of abnormal development have been reported in skates and rays, though most of these reported abnormalities relate to specimens where the pectoral fins are not fully fused to the head, and these deformities have been reported in a range of batoids, including skates (summarised in Table 2), and sting and eagle rays (e.g. Chhapgar, 1964; Bennet, 1964; Easwaran, 1967). Other types of abnormality that have been observed in batoids include two-headed embryos (Lazarus, 1985), specimens with “extra snouts” (McIntosh, 1886), specimens where the rostral cartilage has not extended anteriorly, thus resulting in a blunt-snouted condition (Templeman, 1965), spinal deformities, particularly with regards the tail (Ford, 1930, Templeman, 1965; Du Buit, 1978), albinism and partial albinism (Wilson, 1951; Capapé and Pantoustier, 1975), abnormal dentition (Gudger, 1933), spinulose skin (Du Buit, 1978) and intersexuality and hermpahroditism (Quignard and Negla, 1971; Quignard and Capapé, 1972).

Though there are occasional reports of additional fins in skates, reports of additional fins in teleost fishes tend to be rare (Dawson, 1964, 1966, 1971; Venkateswarlu, 1972; Singh and Reddy, 1989; Raadik, 1993), though this is not surprising given that malformed larval stages are likely to have high mortality. In contrast, skates are oviparous and the embryo develops over a period of several months prior to hatching, with recently hatched fish relatively well developed. This may result in malformed skates having a greater chance of surviving after hatching.



Acknowledgements Thanks to Pete Draper (SFI, Lowestoft) for passing on information regarding the specimen, Bernard Seret (Muséum National d’Histoire Naturelle, Paris) for providing information from early references, and Wangford Veterinary Clinic for providing the X-ray.

References Bennett, P. S. (1964). On an abnormal ray from Vizhingam. Journal of the

Marine Biological Association of India, 6(2): 316–317. Bureau, L. (1890). Sur une monstrosité de la Raie estrellée (Raja asterias

Rond.). Bulletin de la Société Zoologique de France, 14: 313–316. Capapé, C. and Pantoustier, G. (1975). Anomalies chex quelques Sélaciens des

côtes tunisiennes. Archives Institut Pasteur de Tunis, 52(3): 251–260. Chhapgar, B. F. (1964). A monster of the spotted duck-billed ray, Aetobatus

narinari. Copeia 1964(3): 587–589. D’Ancona, U. (1933). Alcuni esemplari anomali di batoidei adriatici.

Thalassia, I(3):1–13. Dawson, C. E. (1964). A bibliography of anomalies of fishes. Gulf Research

Reports 1(6): 308–399. Dawson, C. E. (1966). A bibliography of anomalies of fishes: Supplement 1.

Gulf Research Reports 2(2): 169–176. Dawson, C. E. (1971). A bibliography of anomalies of fishes: Supplement 2.

Gulf Research Reports 3(2): 215–239. Deslongchamps, J.-A. (1853). Mémoire sur une Raie bouclée monstruese.

Memoires Societe Linneenne de Normandie, 9: 138–144. Du Buit, M. H. (1964). Une raie anormale trouvé à Concarneau. Bulletin

Museum d’Histoire Naturelle, Serie 2, 36(2): 180–184. Du Buit, M. H. (1978). Quelques anomalies anatomiques chez les Raies.

Bulletin Office National du Pêche de Tunisie, 2(1–2): 89–96. Easwaran, C. R. (1967). On an abnormal ray from the Gulf of Kutch. Journal

of the Marine Biological Association of India, 9(1): 198–200. Ford, E. (1930). Some abnormal fishes received at the Plymouth Laboratory.

Journal of the Marine Biological Association of the United Kingdom, 17: 53–64.

Grove, D. J. and Roberts, L. B. (1982) A note on an abnormal fin in Raja clavata L. Journal of Fish Biology, 20(5): 607–609.

Gudger, E. W. (1933). Abnormal dentition in rays, Batoidei. Journal of the Elisha Mitchell Scientific Society, 49(1): 57–97.

Harper, W. F. (1933). Supernumerary pectoral fins in Raia circularis Loudon. Proceedings of the Royal Society of Edinburgh B, 53: 26–30.

Hillis, J. P. (1966). Abnormal thornback ray, Raia clavata, from Co. Kerry. Irish Naturalists Journal, 15(6): 182

Johnstone, J. (1906). Ichthyological notes. Report for 1905 on the Lancashire Sea-Fisheries Laboratory, 14: 186–191.

Johnstone, J. (1920). On certain parasites, diseased and abnormal conditions of fishes. Report for 1919 on the Lancashire Sea-Fisheries Laboratory, 28: 24–33.



Lazarus, S. (1985). A note on a two headed embryo of the Javanese cownose ray Rhinoptera javanica Müller and Henle. Journal of the Marine Biological Association of India, 27(1&2): 189–191.

Legendre, R. (1935). Une raie anormale (Raia brachyura Lafont). Bulletin de la Société Zoologique de France, 60: 379–383.

Letaconnoux, R. (1949). Quelques cas tératologiques chez les poissons. Journal du Conseil Permanent International pour l’Exploration de la Mer, 16: 50–58.

McIntosh (1886). Report of the St Andrews Marine Laboratory, No. III. 4th Annual Report of the Fishery Board for Scotland, Appendix, 201–218.

Quignard, J. P. and Capapé, C. (1972). Cas d’hermaphrodisme chex Raja miraletus L. 1758. Travaux du Laboratoire de Biologie Halieutique, Université de Rennes, 6: 133–140.

Quignard, J. P. and Negla, N. (1971). Anomalies au niveau du systeme genmital chez les selaciens Rajiformes. Travaux du Laboratoire de Biologie Halieutique, Université de Rennes, 5: 121–124.

Raadik, T. A. (1993). A specimen of Salmo trutta (Pisces: Salmonidae) possessing an additional dorsal fin. Journal of Fish Biology, 42(5): 811–812

Rennie, J. (1906). Accessory fins in Raia batis. Anatomischer Anzeiger, 28: 428–431.

Schnakenbeck, W. (1942). Eine akzessorische Rückenflosse beim Stachelrochen (Raja clavata). Zoologischer Anzeiger, 140: 88–90.

Singh, H. S; Reddy, T. V. (1989). An additional dorsal fin in Heteropneustes fossilis (Bloch). Journal of Fish Biology, 34(6): 963–964

Templeman, W. (1965). Some abnormalities in skates (Raja) of the Newfoundland area. Journal of the Fisheries Research Board of Canada, 22(1):237–238.

Vaillant, L. (1908). Sur un individu monstrueux myctéridoide du Raja clavata Linné. Bulletin Museum National d’Histoire Naturelle, 14: 112–113.

Venkateswarlu, T. (1972). A note on an abnormal pectoral fin in Puntius amphibia (Val.). Acta Ichthyol. Piscatoria, 2(2): 95–97.

Williamson, H. C. (1911). Notes on the eggs of the angler (Lophius piscatorius), halibut (Hippoglossus vulgaris), Conger vulgaris and tusk (Brosme brosme); a young Arnoglossus sp.; abnormalities in Lophius, Gadus, Raia; diseases in Gadus, Pleuronectes, Onus, Zoarces; occurrence of Himantolophus rheinhardti and Clupea pilchardus; the effectiveness of a seine-trawl in a small pond. 28th Annual Report of the Fishery Board for Scotland, Part III, 46–67.

Wilson, E. (1951). Colour deficiency in skate (Raiidae). Proceedings of the Zoological Society of London, 121, 557–559.

Jim Ellis CEFAS Lowestoft Laboratory Pakefield Road Lowestoft Suffolk NR33 0HT

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AN ABNORMAL THORNBACK RAY RAJA CLAVATA WITH ADDITIONAL PECTORAL FINS