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Elasmobranchs Rajidae (SRX) Bathyraja spp. (BHY) Soft nosed rays Raja spp. (RAJ) Hardnosed Rays Somniosus microcephalus (GSK) Anal fin present Lateral.

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Presentation on theme: "Elasmobranchs Rajidae (SRX) Bathyraja spp. (BHY) Soft nosed rays Raja spp. (RAJ) Hardnosed Rays Somniosus microcephalus (GSK) Anal fin present Lateral."— Presentation transcript:

1 Elasmobranchs Rajidae (SRX) Bathyraja spp. (BHY) Soft nosed rays Raja spp. (RAJ) Hardnosed Rays Somniosus microcephalus (GSK) Anal fin present Lateral keel Elasmobranch 1 Usually large (> 1 m) Etmopterus lucifer (ETF) Dark colour Usually small (<40cm) No anal fin Spines on both dorsal fins Eye very smallNo spines on dorsal fins No anal fin Elephant fish Callorhinchidae (CAH) see sheet ‘Rajid 1’ Shortnose chimaeras or ratfishes Hydrolagus spp. (HYD) Longnose chimaeras Rhinochimaera spp. (RHC) Chimaeras All have two dorsal fins, the first erectile with a short base and preceded by an erectile spine. Note snout and tail configuration. Wide teeth with saw- like edges Narrow teeth with long points Lamna nasus (POR) Extremities of pectoral fin rays Rostral process delicate and flexible Rostral process stout Extremities of pectoral fin rays

2 R. georgiana (SRR) R. georgoana variant (SR2) R. taaf (RFA) 16-28 thorns median row 15-20 thorns median row Raja (Hard nosed Rays) Rajid 1 Bathyraja (Soft nosed Rays) Underside pale 9 - 15 thorns midline of tail only 12 - 26 thorns midline from nape to tail B. maccaini (BAM) B. murrayi (BMU) B. eatonii (BEA) No pre or post orbital thorns 8 - 18 thorns midline of tail only S S R R Underside pigmented U R 9 - 23 thorns on midline of tail B. irrasa (BYR) 37 - 39 thorns in continuous median row No pre or post orbital thorns B. meridionalis (BYE) NOTES R = rough, S = smooth, UR = uniformly rough (unshaven feel) Arrows indicate non median thorns or groups of thorns Dorsal views to show distribution of thorns, Ventral views (smaller) to show pigmentation Upper surface of pelvic fins under disc often pale R dark underside White patches (variable size)

3 Histiobranchus bathybius (HIB) Muraenolepis spp. (MRL) see sheet ‘Teleost 5’ Macrourus spp. (GRV) see sheet ‘Teleost 2’ Dorsal, ventral and tail fins appear combined One dorsal fin First dorsal a ‘filament’ Two dorsal fins Obvious tail Prominent snout Mouth inferior, mental barbel Anal fin in two parts Antimora rostrata (ANT) Halargyreus johnsonii (MHJ) Nototheniidae (NOX) see sheet ‘Teleost 3’ Bathydraconidae Channichthyidae (ICX) see sheet ‘Teleost 4’ White gills Two dorsal fins One dorsal fin Red gills No Obvious tail Swimbladder present - stomach usually everted through mouth when brought up from depth No Swimbladder No pelvic fins Barbel Pelvic fins ‘filaments’ Head ‘flat’ No scales Teleost 1 Mouth terminal, no mental barbel Always scaled Sometimes scaled No scales Scales present but skin feels smooth Obvious scales Opahs: Lampris immaculatus (LAI). Unmistakable, body coloured blue-grey and looks ‘powerful’, fins bright orange Slickheads: Alepocephalus spp. (ALH). Dorsal and Ventral fin bases opposite, no swimbladder.

4 Macrouridae (Grenadiers) Large fang-like teeth, mouth terminal Black all over Cynomacrurus piriei (MNI) Leading edge of First Dorsal smooth Caelorinchus spp. Leading edge of first dorsal serrated C. marinii (CEH) C. fasciatus (CQF) Ridge from snout to pre-opercle ends in sharp point posteriorly, eyes large (NB species are difficult to distinguish) Macrourus spp. (GRV) Infra-orbital ridge, if present, never ending in spine, eyes small, row of teeth in lower jaw Coryphaenoides spp. (CVY) C. filicauda C. ferrieri C. armatus (CKH) C. lecointei M. carinatus (MCC) M. holotrachys (MCH) M. whitsoni (WGR) Barbel thin and short, scales thin, fine and deciduous Scales fairly firm and coarsely spinulated Snout broad and blunt No distinct terminal tubercle Body scales deciduous covered with small fine spinules in parallel rows Snout narrow and pointed with distinct terminal spiny tubercle No scales on underside of head (NB there may be 1 -3 above corner of mouth) Less than 27 scales in diagonal line More than 27 scales in diagonal line Teleost 2 Naked Scaled Scales Position of Ventral fossa relative to Anus

5 Dissostichus mawsoni (TOA) Dissostichus eleginoides (TOP) Middle lateral line Margins of fins often white Margins of fins never white Narrow inter-orbital “Bumphead” Ctenoid (rough) scales Notothenia rossii (NOR) Lepidonotothen squamifrons (NOS) Nototheniidae Red blood, two dorsal fins, scales on body Dark grey transverse band on upper part of eye Small villiform teeth, ctenoid scales over body and head, inter-orbital width narrow (< 12% head length) Cycloid (smooth) scales over body, few scales on head, inter-orbital width wide (~30% head length) Notothenia coriiceps (NOC) Gvozdarus svetovidovi (GZV) No scales on head except for small patch posterior to eye Otolith Scales on head extensive Teleost 3 Large canine-like teeth No obvious middle lateral line Lepidonotothen kempi (NOK) Pectoral fins 21-24 rays Pectoral fins 17-19 rays Gobionotothen gibberifrons (NOG)

6 Notes A=Anal fin; P=Pelvic fin; LL=Lateral Line; RS=Rostral Spine; SP=Spine Chaenocephalus aceratus (SSI) Channichthys rhinoceratus (LIC) Pseudochaenichthys georgianus (SGI) Channichthyidae (ICX) White blood and gills, two dorsal fins, no scales, opercular spines Middle pelvic fin rays longest Leading pelvic fin rays longest, no spine on subopercle or interopercle RS 3 LL RS No RS Head depth=Snout C. gunnari; Head depth < Snout C. esox P 25-28; A 35-40 = C. gunnari; P22-24; A 31-35= C. esox Spines on subopercle and interopercle, 3 LL 2 LL 2 LL with bony plates Teleost 4 2LL Chionodraco myersi (MIC) Chionodraco hamatus (TIC) Chionodraco rastrospinosus (KIF) RS blunt, reduced to Tubercle RS points backwards Five pelvic fin rays, gill rakers dentigerous SP RS reduced to small knob or absent 3 LL Chionobathyscus dewitti (CHW) P Long (reaches A) P Short (just reaches A) 3 LL Cryodraco spp. RS present, points forward Chaenodraco wilsoni (WIC) Four pelvic fin rays 3 LL Five pelvic fin rays Champsocephalus gunnari (ANI) Resembles Chaenocephalus but has 3 LL Five pelvic fin rays, gill rakers vestigial

7 Bothidae (Lefteye or Armless Flounders) No pectoral fins Free pre-opercular margin Achiropsetta tricholepis (HHJ) Eye Dorsal fin Snout with pronounced hump Anus on ‘blind’ side of body Anus on midline Mancopsetta maculata (MMM) Mancopsetta milfordi (PAZ) Pseudomancopsetta andriashevi (UMA) (NB Small, shallow water) Eye and Dorsal fin Scales feel ‘rough’ Scales ‘rough’ only when stroked forwards Muraenolepis spp. (MRL) Snout rounded Snout straight Teleost 5 Mental barbel < eye diameter Mental barbel  eye diameter Distinct lateral line reaching to middle of D2 Indistinct short lateral line, normally no more than 2 pore D1 eye diameter D1 > 4 x eye diameter Mental barbel  eye diameter M. microcephalus (MWS) M. microps (MOY) M. orangiensis (MUO) M. marmoratus (MVC)

8 Lithodidae (Stone crabs, KCX) Abdomen with membraneous region containing calcareous nodules Lithodes spp. (KCZ) 1. Carapace pear-shaped, covered by spinous tubercles: P. aculeata (KCU) ------------------------------------ 2. Carapace rounded, more or less covered with numerous granules: P. anamerae (KDD) ------------------------------------- 3. Entire dorsal surface of carapace covered with numerous spines: P. spinosissima (KCV) --------------------------------- 4. Carapace more or less pentagonal, as long as wide surface covered with small granules and a FEW spines: P. formosa (KCF) --------------------------------- 5. Carapace more or less pentagonal pentagonal with many large spines, walking legs long: Neolithodes diomedeae (NDW) Rostrum Dorsal + Lateral views Abdomen without membraneous areas, the calcareous plates being continuous Paralomis spp. (PAI) or Neolithodes Male Female Rostrum Crab 1 Carapace and legs with unequal spines (sharp) and tubercles L. murrayi (KCM)

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