Chondrichthyes: sharks, skates, rays and chimeras Craig Kasper, Ph. D. Zoology 1450 Chapter 12...
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Transcript of Chondrichthyes: sharks, skates, rays and chimeras Craig Kasper, Ph. D. Zoology 1450 Chapter 12...
Chondrichthyes: Chondrichthyes: sharks, skates, rays and chimeras sharks, skates, rays and chimeras
Craig Kasper, Ph. D. Craig Kasper, Ph. D. Zoology 1450 Zoology 1450
Chapter 12Chapter 12
What’s a chimera??
Sharks: the beginning…or the end??Sharks: the beginning…or the end??
Existence of elasmobranchs with little change is a Existence of elasmobranchs with little change is a testament to their evolutionary success and durabilitytestament to their evolutionary success and durability
Appear in fossil record in late Devonian, 500 mybp Appear in fossil record in late Devonian, 500 mybp (perhaps earlier)(perhaps earlier)
Last class of fishes to appear in fossil recordLast class of fishes to appear in fossil record
Elasmobranch… plate or strap gill
Classification of ChondrichthyesClassification of Chondrichthyes
Class Chondrichthyes (~850 spp.)Class Chondrichthyes (~850 spp.)
– Subclass Elasmobranchi (~820 spp.)Subclass Elasmobranchi (~820 spp.)• sharks, skates and rayssharks, skates and rays
– Subclass Holocephali (~30 spp.)Subclass Holocephali (~30 spp.)• chimaeras, ratfisheschimaeras, ratfishes
Distinguishing Elasmobranch TraitsDistinguishing Elasmobranch Traits
cartilaginous skeletoncartilaginous skeleton absence of swim bladderabsence of swim bladder heterocercal tailheterocercal tail placoid denticles - scales and teethplacoid denticles - scales and teeth spiracle present with 5-7 gill slits (no operculum)spiracle present with 5-7 gill slits (no operculum) urea retained for osmoregulationurea retained for osmoregulation spiral valve in intestinespiral valve in intestine males have clasper organs for internal fertilizationmales have clasper organs for internal fertilization embryonic development with physiological careembryonic development with physiological care
oviparous, ovoviviparous, viviparousoviparous, ovoviviparous, viviparous jaw hyostylic (single connection of upper jaw to neurocranium - adds jaw hyostylic (single connection of upper jaw to neurocranium - adds
protrusibility) or amphistylic (two connection points - anterior and protrusibility) or amphistylic (two connection points - anterior and posterior)posterior)
teeth in rows, areteeth in rows, are constantly replacedconstantly replaced eyes smalleyes small
Holocephali: traitsHolocephali: traits
jaw holostylic (= autostylic = fused to neurocranium)jaw holostylic (= autostylic = fused to neurocranium)spiracle absent; gills covered by single operculumspiracle absent; gills covered by single operculumall oviparousall oviparouscloaca lacking - separate urogenital porecloaca lacking - separate urogenital poreskin lacking scales; placoid spinesskin lacking scales; placoid spinesmales with head claspersmales with head claspers teeth are plate-liketeeth are plate-like, , non-deciduousnon-deciduouseyes largeeyes large
Chondrichthian success story?Chondrichthian success story? Buoyancy control: fatty liver, no swim bladder and no energy requiredBuoyancy control: fatty liver, no swim bladder and no energy required
Swimming adaptations: rigid fins instead of raysSwimming adaptations: rigid fins instead of rays
Body covering: placoid scales, reduce drag (see Helfman, fig. 12.3) Body covering: placoid scales, reduce drag (see Helfman, fig. 12.3)
Osmoregulation adaptationsOsmoregulation adaptations
Reproductive adaptations: self-sufficient youngReproductive adaptations: self-sufficient young
Feeding adaptationsFeeding adaptations
Sensory system: tapetum lucetum, ampullae of LorenziniSensory system: tapetum lucetum, ampullae of Lorenzini
Respiration effectivenessRespiration effectiveness
Hey, if it ain’t broke…
Elasmobranch classificationElasmobranch classificationSuperorder GaleomorphiSuperorder Galeomorphi
• large, pelagic predators, blade-like teethlarge, pelagic predators, blade-like teeth
– Heterodontiformes - horn sharksHeterodontiformes - horn sharks– Orectolobiformes - nurse sharks, whale sharksOrectolobiformes - nurse sharks, whale sharks– Lamniformes - mackerel, mako, white sharksLamniformes - mackerel, mako, white sharks– Carcharhiniformes - requiem sharks (blacktip, Carcharhiniformes - requiem sharks (blacktip,
whitetip, reef, bull), tiger sharks, basking whitetip, reef, bull), tiger sharks, basking sharkssharks
Heterodontiformes - horn sharks
Orectolobiformes - whale sharksOrectolobiformes - whale sharks
Rhincodon typusRhincodon typus
Orectolobiformes –Orectolobiformes –
nurse sharksnurse sharks
Ginglymostoma cirratumGinglymostoma cirratum
Lamniformes - mackerel, mako, white sharksLamniformes - mackerel, mako, white sharks
MakoMako Great White, Great White, Carcharodon carchariasCarcharodon carcharias
Mako Great WhiteGreat White
Isurus oxyrinchusIsurus oxyrinchus
Carcharhiniformes - Carcharhiniformes - requiem sharks (blacktip)requiem sharks (blacktip)
blacktip shark
Carcharhinus limbatusCarcharhinus limbatus
Carcharhiniformes - requiem sharks (whitetip)
Triaenodon obesus
Carchariniformes – bull sharksCarcharhinus leucasCarcharhinus leucas
copyright FLMNH
Carchariniformes – tiger sharksCarchariniformes – tiger sharksGaleocerdo cuvierGaleocerdo cuvier
© George Burgess
Carchariniformes – basking sharksCarchariniformes – basking sharks
Cetorhinus maximus Cetorhinus maximus
Superorder SquatinomorphiSuperorder Squatinomorphi– Squatiniformes-angel sharksSquatiniformes-angel sharks
• bottom-oriented, enlarged pelvic fins, bottom-oriented, enlarged pelvic fins, spike-like teethspike-like teeth
Atlantic Angel Shark, Atlantic Angel Shark, Squatina dumerilSquatina dumeril
Superorder SqualomorphiSuperorder Squalomorphi• smaller, pelagic and benthic sharks, feed on smaller smaller, pelagic and benthic sharks, feed on smaller
prey, some with pointed teeth, some with pavement prey, some with pointed teeth, some with pavement teethteeth
– Squaliformes - dogfish sharksSqualiformes - dogfish sharks– Hexanchiformes - six & seven-gill sharks (cow Hexanchiformes - six & seven-gill sharks (cow
sharks)sharks)– Pristiophoriformes - saw sharksPristiophoriformes - saw sharks
Squaliformes Squaliformes dogfish sharksdogfish sharks
Spiny dogfish-Squalus acanthus
Adipose spine
Hexanchiformes - six & seven-gill sharks (cow sharks)Hexanchiformes - six & seven-gill sharks (cow sharks)
Sevengill SharkSevengill Shark Heptranchias perloHeptranchias perlo
Pristiophoriformes - saw sharksPristiophoriformes - saw sharks
Superorder Batoidea (Rajimorphi)Superorder Batoidea (Rajimorphi)• benthic or pelagic; pectoral fins enlarged, fused with benthic or pelagic; pectoral fins enlarged, fused with
head; gill slits ventral; spiracle large; pavement head; gill slits ventral; spiracle large; pavement teethteeth
– Myliobatiformes - sting rays, eagle & manta Myliobatiformes - sting rays, eagle & manta rays, butterfly raysrays, butterfly rays
– Rajiformes - skatesRajiformes - skates– Pristiformes - sawfishesPristiformes - sawfishes– Torpediniformes - electric raysTorpediniformes - electric rays
Myliobatiformes - sting raysMyliobatiformes - sting rays
eagle & manta rayseagle & manta rays
butterfly raysbutterfly rays
Rajiformes - skatesRajiformes - skates
Skate or Ray...what’s the difference?Skate or Ray...what’s the difference?– Skates (order Rajiformes)Skates (order Rajiformes)
– pelvic fin divided into two lobes pelvic fin divided into two lobes
– stocky tail w/o stinging spine stocky tail w/o stinging spine
– enlarged, thorn-like scales ('bucklers') along the enlarged, thorn-like scales ('bucklers') along the midline of backmidline of back
– males have rows of enlarged scales near the eyes and males have rows of enlarged scales near the eyes and wingtipswingtips
– Rays (order Myliobatiformes):Rays (order Myliobatiformes):
– one-lobed pelvic fin one-lobed pelvic fin
– whip-like tail, usually with stinging spine whip-like tail, usually with stinging spine – no bucklers along back or tail no bucklers along back or tail
Pristiformes - sawfishesPristiformes - sawfishes
Torpediniformes - electric raysTorpediniformes - electric rays