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FACULTY OF SCIENCES
Department of Biology
Evolutionary Morphology of Vertebrates
Early development of Corydoras aeneus
(Siluriformes, Callichthyidae): a case study for
understanding the evolutionary basis of loricarioid
ontogenetic patterning
Part 2 – Figures
Frank Huysentruyt
Thesis submitted to obtain the degree of Doctor in Sciences (Biology) Proefschrift voorgedragen tot het bekomen van de graad Doctor in de Wetenschappen (Biologie)
Academiejaar 2007-2008
Rector: Prof. Dr. Paul van Cauwenberge Decaan: Prof. Dr. Herwig Dejonghe
Promotor: Prof. Dr. Dominique Adriaens
Early development of Corydoras aeneus
(Siluriformes, Callichthyidae): a case study
for understanding the evolutionary basis of
loricarioid ontogenetic patterning
Part 2 - Figures
Frank Huysentruyt
Thesis submitted to obtain the degree of Doctor in Sciences (Biology) Proefschrift voorgedragen tot het bekomen van de graad Doctor in de Wetenschappen (Biologie)
Academiejaar 2007-2008
Rector: Prof. Dr. Paul van Cauwenberge Decaan: Prof. Dr. Herwig Dejonghe
Promotor: Prof. Dr. Dominique Adriaens
TABLE OF CONTENTS
i
TABLE OF CONTENTS
1. General Introduction 1
2. Material and Methods 9
3. Adult Morphology 13
3.1. Adult Osteology 13
3.2. Adult Myology 29
4. Ontogeny 49
4.1. Egg 49
4.2. Early Development and growth 53
4.3. Cranium 65
4.4. Cranial Myology 91
4.5. Postcranial Skeleton 101
4.6. Miniaturization 113
5. General Discussion 137
1 GENERAL INTRODUCTION
1
A
B
C
Fig. 1.1: Different species of the family of Loricariidae. A. Rhineloricaria lima. B. Ancistrus triradiatus. C. Peckoltia vittata. (All pictures from Berra (2001)).
1 GENERAL INTRODUCTION
2
1 GENERAL INTRODUCTION
3
Fig. 1.2: Phylogenetic relationships of the Loricarioidea (De Pinna, 1998).
1 GENERAL INTRODUCTION
4
1 GENERAL INTRODUCTION
5
A
B
C
D
E
Fig. 1.3: Species of the different families of Loricarioidea (except Loricariidae). A. Nematogenyidae (Nematogenys inermis). B. Trichomycteridae (Trichomycterus chapmani). C. Callichthyidae (Corydoras aeneus). D. Scoloplacidae (Scoloplax dicra). E. Astroblepidae (Astroblepus pirrense). (All pictures from Berra (2001), except C from Nijssen (1970)).
1 GENERAL INTRODUCTION
6
1 GENERAL INTRODUCTION
7
A
B
C
Fig. 1.4: Species of the family Mochokidae. A. Chiloglanis normani (algae scraping species). B. Ventral view of the mouth of Chiloglanis normani. C. Synodontis comoensis (Non algae scraping species). (All pictures from Paugy & Roberts (1992)).
2 MATERIAL AND METHODS
8
2 MATERIAL AND METHODS
9
Fig. 2.1: Habitus of an adult Corydoras aeneus specimen (40 mm SL).
2 MATERIAL AND METHODS
10
2 MATERIAL AND METHODS
11
0
5
10
15
20
25
30
35
0 10 20 30 40 50 60 70 80 90 100
age (dph)
SL
(mm
)
Serial sections Double staining (AB+AR) Single staining (AR)
Fig. 2.2: Growth curve showing the different specimens used in this study and their respective treatment.
3 ADULT MORPHOLOGY – ADULT OSTEOLOGY
12
Figure 3.1 – Legend
af anterior fontanel ast asteriscus d-vnat ductus vesica nattatoria fr-II foramen nervus opticus fr-V-VII foramen nervus trigemino-facialis lap lapillus o-apal os autopalatinum o-cl os cleithrum o-fr os frontale o-io-II os infraorbitale II o-lac-ant os lacrymo-antorbitale o-let os lateroethmoideum o-met os mesethmoideum o-mx os maxillare o-nas os nasale o-oc-c os occipitale complex o-op os operculare o-osph os orbitosphenoideum o-par-soc os parieto-supraoccipitale o-pmx os premaxillare o-prot os prooticum o-psph os parasphenoideum o-ptsph os pterosphenoideum o-ptt-pto-scl os posttemporo-pterotico-supracleithrum o-pvm os prevomerale o-sph os sphenoticum pzyg-vert-c postzygapophysis of the vertebral complex rib rib sag sagitta uls upper lateral scute vert-c vertebral complex vc-VI vertebral centre VI
3 ADULT MORPHOLOGY – ADULT OSTEOLOGY
13
A ↑ rostral
B ↑ rostral
Fig. 3.1: A. Dorsal view of the skull in adult Corydoras aeneus. B. Ventral view of the neurocranium in adult Corydoras aeneus (dotted areas represent cartilage).
3 ADULT MORPHOLOGY – ADULT OSTEOLOGY
14
Figure 3.2 – Legend
lig-apal-mx ligamentum autopalatinum-maxillare lig-met-mx ligamentum mesethmoid-maxillare lig-met-pmx ligamentum mesethmoid-premaxillare np nuchal plate o-apal os autopalatinum o-art-c os articulare complex o-ch-a os ceratohyale anterior o-den-c os dentale complex o-fr os frontale o-io-II os infraorbitale II o-iop os interoperculare o-lac-ant os lacrymo-antorbitale o-let os lateroethmoideum o-met os mesethmoideum o-mpt os metapterygoideum o-mx os maxillare o-nas os nasale o-op os operculare o-osph os orbitosphenoideum o-par-soc os parieto-supraoccipitale o-pmx os premaxillare o-pop os preoperculare o-psph os parasphenoideum o-ptsph os pterosphenoideum o-ptt-pto-scl os posttemporo-pterotico-supracleithrum o-q os quadratum o-sph os sphenoticum o-spop os suprapreoperculare r-bs branchiostegal ray
3 ADULT MORPHOLOGY – ADULT OSTEOLOGY
15
A → rostral
B ↑ rostral
Fig. 3.2: A. Lateral view of the skull in adult Corydoras aeneus. B. Mesethmoid-palatine-maxillary mechanism in adult Corydoras aeneus; left: dorsal view; right: ventral view(dotted areas represent cartilage).
3 ADULT MORPHOLOGY – ADULT OSTEOLOGY
16
Figure 3.3 – Legend
rm-ep ramus epiphysealis rm-iob ramus infraorbitalis rm-ot ramus oticus rm-pop ramus preopercularis rm-pot ramus postoticus rm-pto ramus pteroticus rm-ptt ramus posttemporalis rm-sob ramus supraorbitalis
3 ADULT MORPHOLOGY – ADULT OSTEOLOGY
17
A ↑ rostral
B → rostral
Fig. 3.3: The cranial lateral line system in adult Corydoras aeneus. A. Dorsal view. B. Lateral view.
3 ADULT MORPHOLOGY – ADULT OSTEOLOGY
18
Figure 3.4 – Legend
c-Meck cartilago Meckeli lig-art-ch ligamentum articulo-ceratohyale lig-art-iop ligamentum articulo-interoperculare o-art-c os articulare complex o-den-c os dentale complex o-hym os hyomandibulare o-iop os interoperculare o-mpt os metapterygoideum o-op os operculare o-ptt-pto-scl os posttemporo-pterotico-supracleithrum o-q os quadratum o-sph os sphenoticum
3 ADULT MORPHOLOGY – ADULT OSTEOLOGY
19
A → rostral
B ← rostral
Fig. 3.4: A. Lateral view of the right suspensorium, operculum and lower jaw in adult Corydoras aeneus (dotted lines represent removed eye preoperculum and suprapreoperculum; dotted areas represent cartilage). B. Median view of the right lower jaw in adult Corydoras aeneus (dotted areas represent cartilage).
3 ADULT MORPHOLOGY – ADULT OSTEOLOGY
20
Figure 3.5 – Legend
c-p copula posterior lig-art-ch ligamentum articulo-ceratohyale lig-art-iop ligamentum articulo-interoperculare lptpl lower pharyngeal toothplate o-art-c os articulare complex o-bb os basibranchiale o-cb os ceratobranchiale o-ch-a os ceratohyale anterior o-ch-p os ceratohyale posterior o-cl os cleithrum o-den-c os dentale complex o-eb os epibranchiale o-hb os hypobranchiale o-hh-d os hypohyale dorsalis o-hh-v os hypohyale ventralis o-hym os hyomandibulare o-iop os interoperculare o-ipb os infrapharyngobranchiale o-op os operculare o-puh os parurohyale o-q os quadratum r-bs branchiostegal ray uptpl upper pharyngeal toothplate Roman numerals indicate arch number
3 ADULT MORPHOLOGY – ADULT OSTEOLOGY
21
A ↑ rostral
B ↑ rostral Fig. 3.5: A. Dorsal view of the hyoid arch and branchial basket in adult Corydoras aeneus. B. Ventral view of the mandibular arch, hyoid arch and branchial basket in adult Corydoras aeneus (dotted areas represent cartilage).
3 ADULT MORPHOLOGY – ADULT OSTEOLOGY
22
Figure 3.6 – Legend
a-h haemal arch epu epural hyp-I-II hypurals I-II hyp-III-V hypurals III-V np nuchal plate para parapophysis phyp parhypural pr-ph processus posthaemalis pr-pn processus postneuralis pr-prh processus prehaemalis pr-prn processus preneuralis pr-tr processus transversus pty pterygiophore pu-I preural vertebral centre I pu-II preural vertebral centre II pu-III preural vertebral centre III pu-IV preural vertebral centre IV r-dfin dorsal fin ray rib rib r-pri principal fin ray r-pro procurrent fin ray s-dfin-I dorsal fin spine I s-dfin-II dorsal fin spine II s-h haemal spine s-n neural spine us urostyl vc-IX vertebral centre IX
3 ADULT MORPHOLOGY – ADULT OSTEOLOGY
23
A → rostral
B → rostral Fig. 3.6: A. Lateral view of the dorsal fin skeleton in adult Corydoras aeneus. B. Lateral view of the caudal fin skeleton in adult Corydoras aeneus.
3 ADULT MORPHOLOGY – ADULT OSTEOLOGY
24
Figure 3.7 – Legend
s-pfin pectoral fin spine r-pfin pectoral fin ray pns-cor pons coracoideus o-cl os cleithrum rd-pro proximal radial o-sca-cor os scapulocoracoideum
3 ADULT MORPHOLOGY – ADULT OSTEOLOGY
25
↑ rostral
Fig. 3.7: Dorsal view of the pectoral girdle in adult Corydoras aeneus with the cleithrum removed on the left side (dotted areas represent cartilage).
3 ADULT MORPHOLOGY – ADULT OSTEOLOGY
26
Figure 3.8 – Legend
bp basipterygium pr-a-e processus anterior externus pr-a-i processus anterior internus pr-is-d processus ischiacus dorsalis pr-is-v processus ischiacus ventralis
3 ADULT MORPHOLOGY – ADULT OSTEOLOGY
27
A ↑ rostral
B ↑ rostral
C → rostral
Fig. 3.8: The pelvic girdle in adult Corydoras aeneus. A. Dorsal view. B. Ventral view of the left side. C. Median view of the left side (dotted areas represent cartilage).
3 ADULT MORPHOLOGY – ADULT MYOLOGY
28
Figure 3.9 – Legend
lig-art-iop ligamentum articulo-interoperculare lig-prim ligamentum primordium m-A1OST-A3’ musculus adductor mandibulae A1OST-A3’ m-A2 musculus adductor mandibulae A2 m-ad-ap musculus adductor arcus palatini m-ext-t musculus extensor tentaculi m-l-ap musculus levator arcus palatini m-pr-pec musculus protractor pectoralis m-ret-t musculus retractor tentaculi o-apal os autopalatinum o-cl os cleithrum o-den-c os dentale complex o-hym os hyomandibulare o-mx os maxillare o-op os operculare o-osph os orbitosphenoideum o-ptt-pto-scl os posttemporo-pterotico-supracleithrum o-q os quadratum o-sph os sphenoticum
3 ADULT MORPHOLOGY – ADULT MYOLOGY
29
← rostral
Fig. 3.9: Left lateral view of the cranial musculature in adult Corydoras aeneus (eye removed; striping indicates fiber direction).
3 ADULT MORPHOLOGY – ADULT MYOLOGY
30
Figure 3.10 – Legend
m-ad-hym musculus adductor hyomandibulae m-ad-op musculus adductor operculi m-dil-op musculus dilatotor operculi m-l-op musculus levator operculi m-pr-pec musculus protractor pectoralis o-hym os hyomandibulare o-op os operculare
3 ADULT MORPHOLOGY – ADULT MYOLOGY
31
C ← rostral Fig. 3.10: 3-D reconstruction of the left opercular musculature in adult Corydoras aeneus. A. Median view. B. Median view (m-pr-pec and m-lev-op not shown). C. Lateral view (skull roof bones not shown in any reconsruction; striping indicates fiber direction).
A → rostral
B → rostral
3 ADULT MORPHOLOGY – ADULT MYOLOGY
32
Figure 3.11 – Legend
lig-apal-mx ligamentum autopalatinum-maxillare lig-met-mx ligamentum mesethmoid-maxillare lig-met-pmx ligamentum mesethmoid-premaxillare lig-prim ligamentum primordium m-ext-t musculus extensor tentaculi m-ret-t musculus retractor tentaculi o-apal os autopalatinum o-met os mesethmoideum o-mx os maxillare o-pmx os premaxillare
3 ADULT MORPHOLOGY – ADULT MYOLOGY
33
← rostral Fig. 3.11: A. Rostral view of a 3-D reconstruction of the bones of the left autopalatinum-premaxillary-maxillary complex in adult Corydoras aeneus. B. Rostral view of a 3-D reconstruction of the bones and ligaments of the left autopalatinum-premaxillary-maxillary complex in adult Corydoras aeneus. C. Lateral view of a 3-D reconstruction of the bones, ligaments and muscles of the left autopalatinum-premaxillary-maxillary complex in adult Corydoras aeneus. (scale bar and orientation only applicable to C.; scale differs in perspective views A and B).
↓ rostral
3 ADULT MORPHOLOGY – ADULT MYOLOGY
34
Figure 3.12 – Legend
m-ab-pec-sf-v musculus abductor superficialis pectoralis m-hh-ab-a musculus hyohyoideus abductor anterior m-hh-ab-p musculus hyohyoideus abductor posterior m-hh-inf musculus hyohyoideus inferior m-intm-a musculus intermandibularis anterior m-intm-p-d musculus intermandibularis posterior dorsalis m-intm-p-v musculus intermandibularis posterior ventralis mm-hh-ad musculi hyohyoidei adductores m-sh musculus sternohyoideus o-ch-a os ceratohyale anterior o-cl os cleithrum o-den-c os dentale complex o-hh-v os hypohyale ventralis o-iop os interoperculare rr-bs branchiostegal rays
3 ADULT MORPHOLOGY – ADULT MYOLOGY
35
↑ rostral
Fig. 3.12: Ventral view of the cranial musculature in adult Corydoras aeneus (striping indicates fiber direction).
3 ADULT MORPHOLOGY – ADULT MYOLOGY
36
Figure 3.13 – Legend
c-p copula posterior m-l-e musculus levator externus m-l-i musculus levator internus m-obl-d musculus obliquus dorsalis m-obl-v musculus obliquus ventralis m-pcl-e musculus pharyngoclavicularis externus m-pcl-i musculus pharyngoclavicularis internus m-rec-com musculus rectus communis m-rec-v musculus rectus ventralis m-tr-d musculus transversus dorsalis m-tr-v musculus transversus ventralis o-bb os basibranchiale o-cb os ceratobranchiale o-ch-a os ceratohyale anterior o-eb os epibranchiale o-hh-d os hypohyale dorsalis o-hh-v os hypohyale ventralis o-ipb os infrapharyngobranchiale o-oc-c os occipitale complex o-prot os prooticum o-psph os parasphenoideum o-ptt-pto-scl os posttemporo-pterotico-supracleithrum o-puh os parurohyale uptpl upper pharyngeal toothplate Roman numerals indicate arch number
3 ADULT MORPHOLOGY – ADULT MYOLOGY
37
A ↑ rostral
B ↑ rostral
Fig. 3.13: A. Ventral view of the dorsal gill arch muscles in adult Corydoras aeneus. B. Ventral view of the ventral gill arch muscles in adult Corydoras aeneus (striping indicates fiber direction: dotted areas represent cartilage).
3 ADULT MORPHOLOGY – ADULT MYOLOGY
38
Figure 3.14 – Legend
m-ab-pec-sf-d musculus abductor pectoralis superficialis dorsalis m-ab-pec-sf-v musculus abductor pectoralis superficialis ventralis m-ad-pec-prof musculus adductor pectoralis profundus m-arr-pec-v musculus arrector pectoralis ventralis m-hh-ab-a musculus hyohyoideus abductor anterior m-hh-ab-p musculus hyohyoideus abductor posterior m-hh-ad musculus hyohyoideus adductor m-icar-a musculus infracarinalis anterior mm-hyp musculi hypaxiales m-obl-inf musculus obliquus inferior m-obl-sup musculus obliquus superior m-rec-e musculus rectus externus m-rec-i musculus rectus internus m-rec-inf musculus rectus inferior m-rec-sup musculus rectus superior m-sh musculus sternohyoideus n-II nervus opticus o-cl os cleithrum o-sca-cor os scapulocoracoideum r-bs branchiostegal ray r-pfin pectoral fin ray s-pfin pectoral fin spine
3 ADULT MORPHOLOGY – ADULT MYOLOGY
39
A ↑ rostral
B ↑ rostral
Fig. 3.14: A. Graphic reconstruction of a ventral view of the eye musculature in adult Corydoras aeneus. B. Ventral view of the musculature of the pectoral girdle in adult Corydoras aeneus (m-add-prof and m-abd-prof removed on left side; striping indicates fiber direction; dotted areas represent cartilage).
3 ADULT MORPHOLOGY – ADULT MYOLOGY
40
Figure 3.15 – Legend
m-ab-pec-d musculus abductor pectoralis dorsalis m-ab-pec-prof musculus abductor pectoralis profundus m-ad-pec-sf musculus adductor pectoralis superficialis m-arr-pec-d musculus arrector pectoralis dorsalis m-icar-a musculus infracarinalis anterior mm-hyp musculi hypaxiales o-cl os cleithrum o-sca-cor os scapulocoracoideum
3 ADULT MORPHOLOGY – ADULT MYOLOGY
41
Fig. 3.15: A. Medial view of the musculature of the right pectoral girdle in adult Corydoras aeneus. B. Dorsal view of the right pectoral girdle in adult Corydoras aeneus (infracarinalis and hypaxial muscles removed; striping indicates fiber direction).
A ← rostral
B ↑ rostral
3 ADULT MORPHOLOGY – ADULT MYOLOGY
42
Figure 3.16 – Legend
m-ab-pel-prof musculus abductor pelvicus profundus m-ab-pel-sf musculus abductor pelvicus superficialis m-ad-pel-prof musculus adductor pelvicus profundus m-ad-pel-sf musculus adductor pelvicus superficialis m-arr-pel-d musculus arrector pelvicus dorsalis m-arr-pel-v musculus arrector pelvicus ventralis m-icar-a musculus infracarinalis anterior m-icar-m musculus infracarinalis medius mm-hyp musculi hypaxiales pr-a-e processus anterior externus pr-a-i processus anterior internus pr-is-d processu ischiacus dorsalis r-pelfin pelvic fin ray
3 ADULT MORPHOLOGY – ADULT MYOLOGY
43
A ↑ rostral
B ↑ rostral
Fig. 3.16: A. Ventral view of the musculature of the pelvic girdle in adult Corydoras aeneus. B. Ventral view of the musculature of the pelvic girdle in adult Corydoras aeneus (arrector muscles, abductor muscles, hypaxials and infracarinalis muscle removed; striping indicates fiber direction).
3 ADULT MORPHOLOGY – ADULT MYOLOGY
44
Figure 3.17 – Legend
m-depr-d musculus depressor dorsalis m-erec-d musculus erector dorsalis m-erec-d-I musculus erector dorsalis I m-flex-d musculus flexor dorsalis m-flex-d-sup musculus flexor dorsalis superior m-flex-v musculus flexor ventralis m-flex-v-inf musculus flexor ventralis inferior m-hypochor-long musculus hypochordalis longitudinalis m-icar-p musculus infracarinalis posterior m-incl-d musculus inclinator dorsalis mm-intr musculi interradiales m-scar-a musculus supracarinalis anterior m-scar-p musculus supracarinalis posterior pty pterygiophore pu-III preural vertebral centre III r-dfin dorsal fin ray r-pri principal fin ray r-pro procurrent fin ray s-dfin-I dorsal fin spine I s-dfin-II dorsal fin spine II
3 ADULT MORPHOLOGY – ADULT MYOLOGY
45
A ← rostral
B ← rostral
Fig. 3.17: A. Left lateral view of the caudal fin musculature in adult Corydoras aeneus. B. Left lateral view of the dorsal fin musculature in adult Corydoras aeneus (erector muscles removed on last 4 fin rays) (striping indicates fiber direction).
3 ADULT MORPHOLOGY – ADULT MYOLOGY
46
Figure 3.18 – Legend
m-depr-an musculus depressor analis m-erec-an musculus erector analis m-icar-m musculus infracarinalis medius m-icar-p musculus infracarinalis posterior m-incl-an musculus inclinator analis pty pterygiophore r-afin anal fin ray
3 ADULT MORPHOLOGY – ADULT MYOLOGY
47
A ← rostral
B ← rostral
Fig. 3.18: A. Left lateral view of anal fin musculature in adult Corydoras aeneus. B. Left lateral view of anal fin musculature in adult Corydoras aeneus (inclinator muscles removed) (striping indicates fiber direction).
4 ONTOGENY – EGG
48
Figure 4.1 – Legend
ap animal pole mr micropylar region vp vegetal pole y yolk
4 ONTOGENY – EGG
49
A
B Fig. 4.1: Habitus of Corydoras aeneus eggs. A. Light microscopic view. B. S.E.M. view.
4 ONTOGENY – EGG
50
Figure 4.2 – Legend
mc micropylar canal mp micropylar pit mr micropylar region pc pore canal pl micropylar plug ptb protuberance ze zona radiata externa zi zona radiata interna zsi zona radiata subinterna
4 ONTOGENY – EGG
51
Fig. 4.2: S.E.M. view of Corydoras aeneus egg morphology. A. Section of zona radiata with protuberance. B. Attachment site between two separate eggs with lengthened and glued protuberances. C. Protuberance. D. Micrpolyar pit. E. Micropylar region. F. Micropylar canal.
4 ONTOGENY – EARLY DEVELOPMENT AND GROWTH
52
Figure 4.3 – Legend
ABL abdominal length EYE horizontal eye diameter HEAD head length NL notochord length PAL post-anal length PEC pectoral fin length SL standard length CAUDAL caudal fin length
4 ONTOGENY – EARLY DEVELOPMENT AND GROWTH
53
A
B
Fig. 4.3: A. Different measurements taken on Corydoras aeneus as exemplified in a juvenile specimen of 14 mm SL. B. Notochord length measurement in an embryonic specimen of 3.6 mm SL.
4 ONTOGENY – EARLY DEVELOPMENT AND GROWTH
54
4 ONTOGENY – EARLY DEVELOPMENT AND GROWTH
55
A B
C D
E F
Fig. 4.4: Different stages in the development of Corydoras aeneus. A. Eleutherembryonic phase (3.6 mm SL). B. Protopterygiolarval phase (5.3 mm SL). C. Pterygiolarval phase (6.4 mm SL). D. Pterygiolarval phase (8.6 mm SL). E. Pterygiolarval phase (10.7 mm SL). F. juvenile period (14.0 mm SL).
4 ONTOGENY – EARLY DEVELOPMENT AND GROWTH
56
Figure 4.5 – Legend
k̂ estimated slope
4 ONTOGENY – EARLY DEVELOPMENT AND GROWTH
57
Fig. 4.5: Inflexion points in the overall growth curve of Corydoras aeneus.
4 ONTOGENY – EARLY DEVELOPMENT AND GROWTH
58
Figure 4.6 – Legend
k̂ estimated slope
4 ONTOGENY – EARLY DEVELOPMENT AND GROWTH
59
A B
C D
Fig. 4.6: Growth allometries of the different body segments in Corydoras aeneus. A. Growth allometry of the head. B. Growth allometry of the abdomen. C. Growth allometry of the postanal region. D. Growth allometry of the caudal fin.
4 ONTOGENY – EARLY DEVELOPMENT AND GROWTH
60
Figure 4.7 – Legend
k̂ estimated slope
4 ONTOGENY – EARLY DEVELOPMENT AND GROWTH
61
A B
Fig. 4.7: Growth allometries of several body parts in Corydoras aeneus. A. Growth allometry of the eye. B. Growth allometry of the pectoral fin.
4 ONTOGENY – EARLY DEVELOPMENT AND GROWTH
62
4 ONTOGENY – EARLY DEVELOPMENT AND GROWTH
63
Fig. 4.8: Growth profiles during development of Corydoras aeneus. A. 6.3 mm SL (0.8 log SL). B. 10 mm SL (1.0 log SL). C. 15.8 mm SL (1.2 log SL). (Drawings are included for reference to developmental phase, SL can differ slightly from the graph presented; error bars indicate standard error).
A
B
C
4 ONTOGENY – CRANIUM
64
Figure 4.9 – Legend
c-ac cartilago acrochordalis ch ceratohyale cm-bc-a commissura basicapsularis anterior c-ot otic capsule c-pc cartilago parachordalis c-pol cartilago polaris fs-hyp fissura hypophysea fs-met fissura metotica hh hypohyale hs hyosymplecticum hs-ptq hyosymplectic-pterygoquadrate plate lm-bot lamina basiotica not notochord q quadratum tr-cr trabecula cranii
4 ONTOGENY – CRANIUM
65
A ↑ rostral
B ↑ rostral
Fig. 4.9: Dorsal view of a 3D reconstruction of the chondrocranium of Corydoras aeneus. A. 3.3 mm SL. B. 4.0 mm SL.
4 ONTOGENY – CRANIUM
66
Figure 4.10 – Legend
apal autopalatine c-ac cartilago acrochordalis c-eth cartilago ethmoideum ch ceratohyale cm-bc-a commissura basicapsularis anterior cm-bc-p commissura basicapsularis posterior c-Meck cartilago Meckeli cm-lat commissura lateralis c-ot otic capsule c-pc cartilago parachordalis c-pol cartilago polaris fn-bc fenestra basicapsularis fn-hyp fenestra hypophysea fn-sph-p fenestra sphenoidea posterior fr-A foramen “A” fr-X foramen nervus vagus hh hypohyale hs hyosymplecticum ih interhyale not notochord pns-ep pons epiphysealis q quadratum sol-n solum nasi t-m taenia marginalis tr-cr trabecula cranii tt-p tectum posterius
4 ONTOGENY – CRANIUM
67
Fig. 4.10: 3D reconstruction of the chondrocranium of Corydoras aeneus (4.4 mm SL). A. Dorsal view. B. Ventral view of the neurocranium. C. Right lateral view.
↑ rostral
↑ rostral
→ rostral
4 ONTOGENY – CRANIUM
68
Figure 4.11 – Legend apal autopalatine c-ac cartilago acrochordalis c-eth cartilago ethmoideum ch ceratohyale cm-bc-a commissura basicapsularis anterior cm-bc-p commissura basicapsularis posterior cm-bv commissura basivestibularis c-Meck cartilago Meckeli cm-lat commissura lateralis cm-spheth commissura sphenoethmoidalis cm-sphsep commissura sphenoseptalis c-ot otic capsule c-pc cartilago parachordalis fn-bc-a fenestra basicapsularis anterior fn-hyp fenestra hypophysea fr-A foramen “A” fr-IX foramen nervus glossopharyngeus (fenestra basicapsularis
posterior) fr-X foramen nervus vagus hh hypohyale hs hyosymplecticum ih interhyale lm-on lamina orbitonasalis not notochord pns-ep pons epiphysealis pr-pt processus pterygoideus q quadratum sol-n solum nasi t-m-a taenia marginalis anterior t-m-p taenia marginalis posterior tr-cr trabecula cranii tt-p tectum posterius
4 ONTOGENY – CRANIUM
69
Fig. 4.11: 3D reconstruction of the chondrocranium of Corydoras aeneus (4.9 mm SL). A. Dorsal view. B. Ventral view of the neurocranium. C. Right lateral view.
↑ rostral
↑ rostral
→ rostral
4 ONTOGENY – CRANIUM
70
Figure 4.12 – Legend apal autopalatine b-pob preorbital base c-eth cartilago ethmoideum ch ceratohyale cm-bc-a commissura basicapsularis anterior cm-bc-p commissura basicapsularis posterior cm-bv commissura basivestibularis c-Meck cartilago Meckeli cm-lat commissura lateralis cm-spheth commissura sphenoethmoidalis cm-sphsep commissura sphenoseptalis c-ot otic capsule fn-bc-a fenestra basicapsularis anterior fn-hyp fenestra hypophysea fn-sph fenestra sphenoidea fr-car-i foramen arteria carotis interna fr-f-olf foramen fila olfactoria fr-on foramen orbitonasalis fr-IX foramen nervus glossopharyngeus (fenestra basicapsularis
posterior) fr-X foramen nervus vagus hh hypohyale hs hyosymplecticum ih interhyale lm-on lamina orbitonasalis lm-prc lamina precerebralis not notochord pns-ep pons epiphysealis q quadratum pr-pt processus pterygoideus sol-n solum nasi t-m taenia marginalis tr-cr trabecula cranii tt-p tectum posterius
4 ONTOGENY – CRANIUM
71
Fig. 4.12: 3D reconstruction of the chondrocranium of Corydoras aeneus (5.3 mm SL). A. Dorsal view. B. Ventral view of the neurocranium. C. Right lateral view.
↑ rostral
↑ rostral
→ rostral
4 ONTOGENY – CRANIUM
72
Figure 4.13 – Legend
c-a copula anterior cb ceratobranchial c-p copula posterior eb epibranchial hb hypobranchial ipb infrapharyngobranchial ipb-a infrapharyngobranchial anterior ipb-p infrapharyngobranchial posterior Roman numerals indicate arch number /-symbol indicates fusion of elements
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73
↓ rostral
Fig. 4.13: 3D reconstruction of right halve of the branchial basket of Corydoras aeneus. A. Stage 2. Dorsal view. B. Stage 2. Ventral view. C. Stage 3. Dorsal view. D. Stage 4. Dorsal view. E. Stage 5. Dorsal view. F. Stage 6. Dorsal view.
4 ONTOGENY – CRANIUM
74
Figure 4.14 – Legend
apal autopalatine c-bmax maxillary barbel cartilage cb-V ceratobranchiale V c-eth cartilago ethmoideum c-Meck cartilago Meckeli c-smax cartilago submaxillaris eb-IV epibranchiale IV ipb-p infrapharyngobranchiale posterior lptp lower pharyngeal toothplate nc neurocranium o-dent os dentale o-mx os maxillare o-pmx os premaxillare tp tooth primordium uptp upper pharyngeal toothplate
4 ONTOGENY – CRANIUM
75
Fig. 4.14: Histological sections through details of the osteocranium in 4.4 (A-B), 4.9 (C-D) and 5.3 (E-F) mm SL Corydoras aeneus. A. Lower jaw with tooth primordia, bone absent. B. Primordia of dorsal pharyngeal teeth, bone absent. C. Lower jaw with tooth primordia, dentary bone present. D. Palatine-maxillary articulation maxillary and premaxillary bone and submaxillary cartilage. E. Primordia of ventral pharyngeal teeth with ossified tooth plate. F. Primordia of dorsal pharyngeal teeth with ossified tooth plate.
4 ONTOGENY – CRANIUM
76
Figure 4.15 – Legend
fn-sph fenestra sphenoidea fr-f-olf foramen fila olfactoria fr-on foramen orbitonasalis o-apal os autopalatinum o-art os articulare o-ch-a os ceratohyale anterior o-ch-p os ceratohyale posterior o-den-c os dentale complex o-dent os dentale o-dsph os dermosphenoticum o-fr os frontale o-hh-v os hypohyale ventralis o-hym os hyomandibulare o-iop os interoperculare o-met os mesethmoideum o-mMeck os mentomeckelium o-mpt os metapterygoideum o-mx os maxillare o-op os operculare o-osph os orbitosphenoideum o-par-soc os parieto-supraoccipitale o-pmx os premaxillare o-pop os preoperculare o-psph os parasphenoideum o-ptt-pto-scl os posttemporo-pterotico-supracleithrum o-puh os parurohyale o-pvm os prevomerale o-q os quadratum o-rart os retroarticulare o-set os supraethmoideum o-spop os suprapreoperculare pal-spl palatal splint r-bs branchiostegal ray t-vnat tunica vesica nattatoria
4 ONTOGENY – CRANIUM
77
A → rostral
B → rostral Fig. 4.15: Lateral view of the skull of Corydoras aeneus. A. 8.2 mm SL. B. 9.7 mm SL.
4 ONTOGENY – CRANIUM
78
Figure 4.16 – Legend
fn-sph fenestra sphenoidea fr-f-olf foramen fila olfactoria ll-os lateral line ossicle o-apal os autopalatinum o-art-c os articulare complex o-ch-a os ceratohyale anterior o-ch-p os ceratohyale posterior o-den-c os dentale complex o-fr os frontale o-hh-v os hypohyale ventralis o-hym os hyomandibulare o-ih os interhyale o-iop os interoperculare o-let os lateroethmoideum o-met os mesethmoideum o-mpt os metapterygoideum o-mx os maxillare o-op os operculare o-osph os orbitosphenoideum o-par-soc os parieto-supraoccipitale o-pet os parethmoideum o-pfr os prefrontale o-pmx os premaxillare o-pop os preoperculare o-psph os parasphenoideum o-ptsph os pterosphenoideum o-ptt-pto-scl os posttemporo-pterotico-supracleithrum o-puh os parurohyale o-pvm os prevomerale o-q os quadratum o-sph os sphenoticum o-spop os suprapreoperculare pal-spl palatal splint r-bs branchiostegal ray
4 ONTOGENY – CRANIUM
79
A → rostral
B → rostral
Fig. 4.16: Lateral view of the skull of Corydoras aeneus. A. 11.2 mm SL. B. 13.9 mm SL.
4 ONTOGENY – CRANIUM
80
Figure 4.17 – Legend
fn-sph fenestra sphenoidea o-apal os autopalatinum o-ch-a os ceratohyale anterior o-ch-p os ceratohyale posterior o-den-c os dentale complex o-fr os frontale o-hh-v os hypohyale ventralis o-hym os hyomandibulare o-ih os interhyale o-io-I os infraorbitale I o-io-II os infraorbitale II o-iop os interoperculare o-let os lateroethmoideum o-met os mesethmoideum o-mpt os metapterygoideum o-mx os maxillare o-nas os nasale o-op os operculare o-osph os orbitosphenoideum o-par-soc os parieto-supraoccipitale o-pmx os premaxillare o-pop os preoperculare o-psph os parasphenoideum o-ptsph os pterosphenoideum o-ptt-pto-scl os posttemporo-pterotico-supracleithrum o-pvm os prevomerale o-q os quadratum o-sph os sphenoticum o-spop os suprapreoperculare pal-spl palatal splint r-bs branchiostegal ray
4 ONTOGENY – CRANIUM
81
A → rostral
B → rostral Fig. 4.17: Lateral view of the skull of Corydoras aeneus. A. 16 mm SL. B. 18 mm SL.
4 ONTOGENY – CRANIUM
82
Figure 4.18 – Legend
fn-hyp fenestra hypophysea fn-sph fenestra sphenoidea o-boc os basioccipitale o-eoc os exoccipitale o-fr os frontale o-let os lateroethmoideum o-met os mesethmoideum o-osph os orbitosphenoideum o-prot os prooticum o-psph os parasphenoideum o-ptsph os pterosphenoideum o-ptt-pto-scl os posttemporo-pterotico-supracleithrum o-pvm os prevomerale o-sph os sphenoticum pal-spl palatal splint
4 ONTOGENY – CRANIUM
83
A → rostral
B → rostral Fig. 4.18: Ventral view of the neurocranium of Corydoras aeneus. A. 9.7 mm SL. B. 13.9 mm SL.
4 ONTOGENY – CRANIUM
84
Figure 4.19 – Legend
fn-sph fenestra sphenoidea o-fr os frontale o-let os lateroethmoideum o-met os mesethmoideum o-oc-c os occipitale complex o-osph os orbitosphenoideum o-prot os prooticum o-psph os parasphenoideum o-ptsph os pterosphenoideum o-ptt-pto-scl os posttemporo-pterotico-supracleithrum o-pvm os prevomerale o-sph os sphenoticum
4 ONTOGENY – CRANIUM
85
→ rostral Fig. 4.19: Ventral view of the neurocranium of an 18 mm SL Corydoras aeneus.
4 ONTOGENY – CRANIUM
86
Figure 4.20 – Legend
o-ch-a os ceratohyale anterior o-ch-p os ceratohyale posterior o-hh-d os hypohyale dorsalis o-hh-v os hypohyale ventralis o-puh os parurohyale
4 ONTOGENY – CRANIUM
87
↑ rostral Fig. 4.20: Ventral view of the hyoid of Corydoras aeneus: A. 8.2 mm SL. B. 9.7 mm SL. C. 11.2 mm SL. D. 13.9 mm SL.
4 ONTOGENY – CRANIUM
88
Figure 4.21 – Legend
bb basibranchial c-a copula anterior cb ceratobranchial c-p copula posterior eb epibranchial hb hypobranchial ipb-a infrapharyngobranchial anterior ipb-p infrapharyngobranchial posterior lptp lower pharyngeal toothplate uptp upper pharyngeal toothplate Roman numerals indicate arch number. /-symbol indicates fusion of elements.
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89
↓ rostral Fig. 4.21: Branchial basket of Corydoras aeneus. A. 8.2 mm SL. B. 9.7 mm SL. C. 11.2 mm SL. D. 13.9 mm SL.
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90
Figure 4.22 – Legend
c-ot otic capsule c-pc cartilago parachordalis c-pol cartilago polaris hs-ptq hyosymplectic-pterygoquadrate plate lm-bot lamina basiotica mmp mandibular muscle plate
4 ONTOGENY – CRANIAL MYOLOGY
91
→ rostral Fig. 4.22: Right lateral view of a 3D reconstruction of the chondrocranium and associated muscles of Corydoras aeneus (3.3 mm SL).
4 ONTOGENY – CRANIAL MYOLOGY
92
Figure 4.23 – Legend
ch ceratohyale c-ot otic capsule c-pc cartilago parachordalis hh hypohyale hmp-cd constrictor dorsalis of the hyoid muscle plate hs hyosymplecticum m-dil-op musculus dilatator operculi m-inth-p musculus interhyoideus posterior m-l-ap musculus levator arcus palatini mmp-cv constrictor ventralis of the mandibular muscle plate m-pr-pec musculus protractor pectoralis q quadratum tr-cr trabecula cranii
4 ONTOGENY – CRANIAL MYOLOGY
93
A → rostral
B → rostral
Fig. 4.23: 3D reconstruction of the chondrocranium and associated muscles of Corydoras aeneus (4.0 mm SL). A. Right lateral view. B. Ventral view.
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94
Figure 4.24 – Legend
apal autopalatinum c-eth cartilago ethmoideum ch ceratohyale c-Meck cartilago Meckeli hh hypohyale hmp-cd constrictor dorsalis of the hyoid muscle plate hs hyosymplecticum ih interhyale m-ad-ap musculus adductor arcus palatini m-ad-hym musculus adductor hyomandibulae m-ad-m musculus adductor mandibulae m-dil-op musculus dilatator operculi m-ext-t musculus extensor tentaculi m-inth-p musculus interhyoideus posterior m-intm-a musculus intermandibularis anterior m-intm-p musculus intermandibularis posterior m-l-ap musculus levator arcus palatini m-pr-pec musculus protractor pectoralis m-ret-t musculus retractor tentaculi m-sh musculus sternohyoideus o-op os operculare pns-ep pons epiphysealis q quadratum t-m taenia marginalis tt-p tectum posterius
4 ONTOGENY – CRANIAL MYOLOGY
95
A → rostral
B → rostral Fig. 4.24: 3D reconstruction of the chondrocranium and associated muscles of Corydoras aeneus (4.4 mm SL). A. Right lateral view. B. Ventral view (opercle, hyoid and associated muscles, lower jaw and associated muscles removed on left side).
4 ONTOGENY – CRANIAL MYOLOGY
96
Figure 4.25 – Legend
apal autopalatinum c-eth cartilago ethmoideum ch ceratohyale c-Meck cartilago Meckeli hh hypohyale hs hyosymplecticum ih interhyale m-ad-ap musculus adductor arcus palatini m-ad-hym musculus adductor hyomandibulae m-ad-m musculus adductor mandibulae m-ad-op musculus adductor operculi m-dil-op musculus dilatator operculi m-ext-t musculus extensor tentaculi m-inth-p musculus interhyoideus posterior m-intm-a musculus intermandibularis anterior m-intm-p musculus intermandibularis posterior m-l-ap musculus levator arcus palatini m-l-op musculus levator operculi m-pr-pec musculus protractor pectoralis m-ret-t musculus retractor tentaculi m-sh musculus sternohyoideus o-op os operculare q quadratum sol-n solum nasi t-m taenia marginalis tt-p tectum posterius
4 ONTOGENY – CRANIAL MYOLOGY
97
A → rostral
B → rostral Fig. 4.25: 3D reconstruction of the chondrocranium and associated muscles of Corydoras aeneus (4.9 mm SL). A. Right lateral view. B. Ventral view (opercle, hyoid and associated muscles, lower jaw and associated muscles removed on left side).
4 ONTOGENY – CRANIAL MYOLOGY
98
Figure 4.26 – Legend
cb-V ceratobranchiale V c-Meck cartilago Meckeli m-A1OST-A3’ musculus adductor mandibulae A1OST-A3’ m-A2 musculus adductor mandibulae A2 m-ad-m musculus adductor mandibulae m-ext-t musculus extensor tentaculi m-hh-ab musculus hyohyoideus abductor mm-hh-ad musculi hyohyoidei adductores m-ret-t musculus retractor tentaculi q quadratum
4 ONTOGENY – CRANIAL MYOLOGY
99
Fig. 4.26: Histological sections showing aspects of detailed muscular ontogeny in Corydoras aeneus. A. Section through lower jaw-suspensorium articulation showing an undifferentiated adductor mandibulae (4.9 mm SL). B. Section through lower jaw-suspensorium articulation showing further differentiation in the adductor mandibulae (5.3 mm SL). C. Section through anterior part of last branchial arch showing differentiation in hyohyoidei muscles (5.3 mm SL).
4 ONTOGENY – POSTCRANIAL SKELETON
100
Figure 4.27 – Legend
fr fin ray fs-I first fin spine fs-II second fin spine hsp haemal spine nc notochord nsp neural spine pr proximal radial pr-tr processus transversus pty pterygiophore pty-I pterygiophore of first fin spine pty-II pterygiophore of second fin spine vc vertebral centre
4 ONTOGENY – POSTCRANIAL SKELETON
101
A ← rostral
B ← rostral
C ← rostral
Fig. 4.27: Overview of the postcranial ontogeny of Corydoras aeneus. A. 6.2 mm SL. B. 7.8 mm SL. C. 8.2 mm SL.
4 ONTOGENY – POSTCRANIAL SKELETON
102
Figure 4.28 – Legend
epu epural hsp pu-II haemal spine of the second preural centre hyp-d dorsal hypural plate hyp-v ventral hypural plate nc notochord nsp pu-II neural spine of the second preural centre phyp parhypural pu-I first preural centre pu-II second preural centre us urostyl
4 ONTOGENY – POSTCRANIAL SKELETON
103
← rostral Fig. 4.28: Ontogeny of the caudal skeleton in Corydoras aeneus. A. 4.8 mm SL. B. 5.2 mm SL. C. 5.4 mm SL. D. 5.7 mm SL. E. 6.2 mm SL. F. 7.2 mm SL. G. 7.7 mm SL. H. 8.2 mm SL. I. 9.7 mm SL. J. 35 mm SL.
4 ONTOGENY – POSTCRANIAL SKELETON
104
Figure 4.29 – Legend
dr distal radial fr fin ray fs-I first fin spine fs-II second fin spine np nuchal plate pr-tr processus transversus pr proximal radial pty-I pterygiophore of first fin spine pty-II pterygiophore of second fin spine
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105
A B
C D ← rostral Fig. 4.29: Ontogeny of the dorsal fin skeleton in Corydoras aeneus. A. 9.1 mm SL. B. 11.7 mm SL. C. 12.5 mm SL. D. 15.0 mm SL.
4 ONTOGENY – POSTCRANIAL SKELETON
106
Figure 4.30 – Legend
dr distal radial fr fin ray fs fin spine pr proximal radial
4 ONTOGENY – POSTCRANIAL SKELETON
107
A B ← rostral
Fig. 4.30: Ontogeny of the anal fin skeleton in Corydoras aeneus. A. 11.7 mm SL. B. 15.0 mm SL.
4 ONTOGENY – POSTCRANIAL SKELETON
108
Figure 4.31 – Legend
o-cl os cleithrum dr distal radial ed endoskeletal disc fr fin ray fs fin spine mdz zone of matrix decomposition pr proximal radial pr-cor processus coracoideus pr-sca processus scapularis sca-cor scapulocoracoideum o-sca-cor os scapulocoracoideum
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109
← rostral
Fig. 4.31: Ontogeny of the pectoral girdle in Corydoras aeneus. A. 6.2 mm SL. B. 6.6 mm SL. C. 8.0 mm SL. D. 9.7 mm SL. E. 12.5 mm SL.
4 ONTOGENY – POSTCRANIAL SKELETON
110
Figure 4.32 – Legend
aep anterior external process aip anterior internal process bp basipterygium dip dorsal ischiac projection fr fin ray lp lateral process vip ventral ischiac projection + symbol indicates fusion
4 ONTOGENY – POSTCRANIAL SKELETON
111
↑ rostral Fig. 4.32: Ontogeny of the pelvic girdle in Corydoras aeneus. A. 8.2 mm SL. B. 9.7 mm SL. C. 11.7 mm SL. D. 16 mm SL.
4 ONTOGENY – MINIATURIZATION
112
Figure 4.33 – Legend
k̂ estimated slope
4 ONTOGENY – MINIATURIZATION
113
A
B
Fig. 4.33: A. Inflexion point in the overall growth curve of Corydoras pygmaeus. B. Comparison of inflexion points in the overall growth curves of Corydoras aeneus and Corydoras pygmaeus.
4 ONTOGENY – MINIATURIZATION
114
4 ONTOGENY – MINIATURIZATION
115
Fig. 4.34: Different stages in the development of Corydoras pygmaeus. A. Eleutherembryonic phase (4.2 mm SL). B. Protopterygiolarval phase (4.8 mm SL). C. Pterygiolarval phase (6.2 mm SL). D. Juvenile period (8.9 mm SL).
4 ONTOGENY – MINIATURIZATION
116
Figure 4.35 – Legend
apal autopalatine c-eth cartilago ethmoideum cm-bc-a commissura basicapsularis anterior c-Meck cartilago Meckeli cm-lat commissura lateralis c-ot otic cartilage fn-bc-a fenestra basicapsularis anterior fn-hyp fenestra hypophysea fn-met fenestra metotica fr-A foramen “A” fr-X foramen X hh hypohyale hs-ptq hyosymplectic-pterygoquadrate plate o-dent os dentale o-pmx os premaxillare pns-ep pons epiphysealis t tooth t-m-p taenia marginalis posterior tr-cr trabecula cranii tt-p tectum posterius
4 ONTOGENY – MINIATURIZATION
117
Fig. 4.35: Ontogeny of the skull in Corydoras pygmaeus. A. Dorsal view (3.7 mm SL). B. Ventral view of lower and upper jaw (3.7 mm SL). C. Dorsal view (4.3 mm SL).
→ rostral
↑ rostral
→ rostral
4 ONTOGENY – MINIATURIZATION
118
Figure 4.36 – Legend
brb branchial basket ch ceratohyale c-Meck cartilago Meckeli cm-spheth commissura sphenoethmoidalis cm-sphsep commissura sphenoseptalis c-ot otic cartilage hh hypohyale hs hyosymplecticum ih interhyale q quadratum sol-n solum nasi t-m-p taenia marginalis posterior tt-p tectum posterius
4 ONTOGENY – MINIATURIZATION
119
Fig. 4.36: Skull in a 4.8 mm SL specimen of Corydoras pygmaeus. A. Dorsal view. B. Ventral view. C. Left lateral view.
→ rostral
→ rostral
← rostral
4 ONTOGENY – MINIATURIZATION
120
Figure 4.37 – Legend
c-eth cartilago ethmoideum c-ot otic cartilage o-puh os parurohyale pr-op processus opercularis pr-pt processus pterygoideus sol-n solum nasi tt-p tectum posterius
4 ONTOGENY – MINIATURIZATION
121
Fig. 4.37: Skull in a 6.6 mm SL specimen of Corydoras pygmaeus. A. Dorsal view. B. Ventral view. C. Right lateral view.
→ rostral
→ rostral
→ rostral
4 ONTOGENY – MINIATURIZATION
122
Figure 4.38 – Legend
o-apal os autopalatinum o-art-c os articulare complex o-ch-a os ceratohyale anterior o-ch-p os ceratohyale posterior o-den-c os dentale complex o-sph os sphenoticum o-fr os frontale o-hym os hyomandibulare o-ih os interhyale o-iop os interoperculare o-met os mesethmoideum o-mpt os metapterygoideum o-mx os maxillare o-op os operculare o-par-soc os parieto-supraoccipitale o-pmx os premaxillare o-pop os preoperculare o-psph os parasphenoideum o-ptt-pto-scl os posttemporo-pterotico-supracleithrum o-puh os parurohyale o-pvm os prevomerale o-q os quadratum r-bs branchiostegal ray
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123
Fig. 4.38: Ontogeny of the skull in Corydoras pygmaeus. A. Detail of right lateral view (7.9 mm SL). B. Left lateral view (9.1 mm SL).
→ rostral
← rostral
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124
Figure 4.39 – Legend
o-io-I os infraorbitale I o-io-II os infraorbitale II o-let os lateroethmoideum o-osph os orbitosphenoideum o-ptsph os pterosphenoideum
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125
Fig. 4.39: Ontogeny of the skull in Corydoras pygmaeus. A. Detail of left lateral view (10.0 mm SL). B. Left lateral view (16 mm SL).
← rostral
← rostral
4 ONTOGENY – MINIATURIZATION
126
Figure 4.40 – Legend
epu epural hsp pu-II haemal spine of the second preural centre hy-d dorsal hypural plate hy-v ventral hypural plate nc notochord nsp pu-II neural spine of the second preural centre pu-I first preural centre pu-II second preural centre us urostyl
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127
A B
C D
E F G ← rostral Fig. 4.40: Ontogeny of the caudal skeleton in Corydoras pygmaeus. A. 3.7 mm SL. B. 5.6 mm SL. C. 6.6 mm SL. D. 7.5 mm SL. E. 8.5 mm SL. F. 9.1 mm SL. G. 10.0 mm SL.
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128
Figure 4.41 – Legend
dr distal radial fr fin ray fs-I first fin spine fs-II second fin spine np nuchal plate pr proximal radial pr-tr processus transversus pty-I pterygiophore of first fin spine pty-II pterygiophore of second fin spine
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129
Fig. 4.41: Ontogeny of the dorsal fin skeleton in Corydoras pygmaeus. A. 7.5 mm SL. B. 9.1 mm SL. C. 10.8 mm SL.
← rostral
← rostral
← rostral
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130
Figure 4.42 – Legend
o-cl os cleithrum dr distal radial fr fin ray fs fin spine mdz zone of matrix decomposition pr proximal radial pr-cor processus coracoideus pr-sca processus scapularis o-sca-cor os scapulocoracoideum
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131
Fig. 4.42: Ontogeny of the pectoral fin skeleton in Corydoras pygmaeus. A. 6.6 mm SL. B. 9.4 mm SL. C. 10.8 mm SL.
← rostral
← rostral
← rostral
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132
Figure 4.43 – Legend
4 ONTOGENY – MINIATURIZATION
133
A
B
Fig. 4.43: Comparison of ontogenies of Corydoras aeneus and Corydoras pygmaeus. A. Comparison based on SL (mm). B. Comparison based on age (dpf).
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134
4 ONTOGENY – MINIATURIZATION
135
Ontogene tic indexes (ha tching, yo lk dep le tion, onse t o f finfo ld d iffe rentia tion)
0.0 20.0 40.0 60.0 80.0 100.0
C. pygmaeus C. aeneus
Fig. 4.44: Comparison of ontogenetic indexes for hatching, yolk depletion and finfold differentiation of Corydoras aeneus and Corydoras pygmaeus.
5 GENERAL DISCUSSION
136
Figure 4.45 – Legend
5 GENERAL DISCUSSION
137
A
B
C
Fig. 4.45: Comparison based on SL of ontogenies of Corydoras aeneus, Corydoras pygmaeus and Ancistrus cf. triradiatus