Lab - Shark Classification Flashcards
subclasses..
elasmobranchii, holocephali
elasmobranchii contains superorders..
batoidea and selachimorpha
holocephalian traits
like sharks: fatty liver, cartilaginous, internal fertilization, ceratotrichia, but also have holostylic jaws, no scales, single gill covering, and the tentaculum
tentaculum
weird anterior head protrusion on holocephalians that might be used for holding onto during copulation
torpediniformes
order in batoidea of electric rays. muscular, short tail with caudal fin. no thorns or denticles.
rhinopristiformes
order in batoidea with sawfish/carpenter sharks, guitarfish (they are RAYS). use rostrum to dig in substrate and sense surroundings. uniform saw teeth, no barbels, gills are ventral
rajiformes
order in batoidea containing rays, skates, guitarfish. not venomous (no barb). no caudal fins, very reduced.
myliobatiformes
order in batoidea including stingrays, manta rays, devil rays. have stingers, long, thin, tails. the planktonivores (pelagic) have longer pectoral fins and anterior mouths.
skates vs rays
skates are oviparous and have a dorsal fin, while rays are ovoviviparous
hexanchiformes
order in selachii. frilled sharks, cow sharks. 6-7 gill slits, single dorsal fin, ovoviviparous. weird spiny teeth. longest gestation period ever (3.5 years)
squaliformes
order in selachii. smaller sharks, dogfish, cookiecutter. no anal fin, 2 dorsal fins with spines, 5 gill slits. 20 very small spp, a few bioluminescent
echinorhiniformes
order in selachii. bramble sharks . 2 spp. spineless dorsal fin, no anal fin, patches of large denticles
squatiniformes
order in selachii. 1 genus, angel sharks. large spiracles, 5 gill slits, ovoviviparous, look like rays except terminal mouth and dorsal gills
pristiophoriformes
order in selachii. saw sharks. gill slits on the side of head, alternating spine lengths, barbels on rostrum. no spines on anal or dorsal fins.
heterodontiformes
order in selachii. bullhead sharks.. WEIRD. blunt head, eye ridges, anterior mouth. very odd teeth. oviparous