Sharks Exam 1 Flashcards
All Chondricthyes have?
tesserae, claspers, placoid scales, polyphyodont teeth, cartilaginous skeleton, skull has no sutures, fins have cartilage and ceratrichia, no swim bladder
What does Chondricthyes include?
Elasmobranchii and holocephali
What is Holocephali?
Chimaeras
What do elasmobranchii include?
cladoselache, xenacanthus, ctenacanthus, hybodus, galeomorphs, squaliformes, batoidea
What does euselachii include?
hybodus, Galeomorphs, squaliformes, batoidea
What does Neoselachii include?
Galeomorphs, squaliformes, Batoidea
What does squalea include?
Squaliformes and batoidea
What was unique to Chimeras?
upper fused jaw to cranium, operculum covers four gill slit, male head clasper, swim with pectoral fin, some have bifurcated claspers
What belongs to Chimeras?
ratfish
What do cladoselache have?
Two Spines?
What is included in the order - Carchariniformes?
catsharks, houndsharks, carcharhinidae - requiem sharks, sphyridae - hammerhead sharks (bonnethead)
What is included in the order of Lamniformes?
sandtiger, goblin, crocodile, megamouth, thresher, basking, mackerel sharks - white shark
What is included in the order of Orectolobiformes?
Carpet, wobbegong, bamboo, nurse, zebra, wale sharks
What is included in the order of Heterodontiformes?
Bullhead sharks - different kinds of teeth, pointy and crushing, spine on back dorsal
What is included in the order of Hexanchiformes?
frill, sevengill, six gill - squalomorphi
What is included in the order of Echinorhiniformes?
Bramble and prickly sharks - have modified scales
What is included in the order of Squaliformes?
sleeper, Greenland, lantern, dogfish, gulper, kitefin, rough sharks, cookiecutter
What is included in the order of squatiniformes?
angel sharks - depressed sharks live on the bottom
What is included in the order of Pristiophoriformes?
saw sharks - rostrum with teeth, live on bottom
What are characteristic of batoid?
kinetic upper jaw, 5 ventral gill slits, males one clasper on each pelvic fin, dorsoventrally flattened, pectorals fused to head, most derived - split later
What is included in Batoidea?
skates, rays and pristiformes, rhinobatiformes, torpedoformes, rajiformes, myliobatiformes,
What is pristiformes?
saw fish
What is Rhinobatiformes?
guitarfishes - extendable jaw
What is Rajiformes?
skates - walking appendages
What is Torpediniformes?
electric rays - active electric fish, recharge after use
What is Myliobatiformes?
stingrays - cownose and butterfly rays, himantura (freshwater)
What is heterocercal fin?
Larger fin on top then bottom. Non equal size fin.
What is the spiracle?
air hole
What is on the end of scales?
Bone
Where did shark come from?
derived from boney fish, lost bone, more flexible, lighter
What may be the closest ancestor?
Placoderms
What are tesserae?
prismatic calcified cartilage
mini tiles that strengthen cartilage
on all cartilage
sheet of tesserae
outside of skeleton, inside has uncalcified cartilage
composite material and looks like sandwich
more for strength
What are claspers?
males have extension of pelvic fin
mature males extend past pelvic fin
hard calcified
What determines relativeness in species?
molecular testing
What is special about Cladoselache?
extinct, 5 gill slits, terminal mouth, cladodont teeth, unrestricted notochord turns up ( rod supports back)
What is special about Xenacanthus?
extinct, freshwater, terminal mouth, bottom dwellers, tapered tail
What is special about Ctenacanthus?
extinct, terminal mouth, notochord heterodont teeth, tail more heterocercal
Placoid scales are also called?
Dermal Denticles
What kind of growth do sharks exhibit?
indeterminant growth (continous)
How are teeth attached?
Collagen fibers