SHARKS Phylum Chordata Subphylum Vertebrata Class Chondricthyes Subclass Elasmobranchii (96% of class) Greek: elasmos=plate, branchios=gill * every niche in ocean * internal copulation * viviparous, ovoviviparous, oviparous * slow growing * late reproducing * may have long gestation periods * produce few (but large) young * many long living * top level predators * protruding jaws Viviparous- give birth to live young after internal development. Eggs hatch and pups are nourished via a placenta. Examples of viviparous sharks include the Bull sharks, White-tip reef shark, Lemon shark, Blue shark, Mako, Porbeagle, Salmon shark, the Silver-tip shark, and Hammerheads Ovoviviparous-give birth to live young after internal development. Eggs hatch and pups are nourished via a yolk sac, which it attached to each pup. Great white sharks, spiney dogfish, sawsharks, Mako, crocodile sharks, Cookiecutter sharks, Pelagic thresher, Greenland shark, Gummy shark, Soupfin shark, Pacific Angelshark, Pygmy sharks, Nurse shark, Tiger shark, and Sand tiger sharks reproduce this way. Examples of intra-uterine canabilisms results in reduced litter sizes in these species. Oviparous- female releases eggs to the environment. Pups develop externally in the egg and then hatch. Oviparous sharks include the Zebra shark, the catsharks, swellshark, the necklace carpetshark, some Epaulette sharks, and the Hornshark. Sharks Word Association It was never this way. Everything changed in 1975! "Martin, it's all psychological. You yell barracuda, everybody says, "Huh? What?" You yell shark, we've got a panic on our hands on the Fourth of July." "Mr. Vaughn, what we are dealing with here is a perfect engine, an eating machine. It's really a miracle of evolution. All this machine does is swim and eat and make little sharks, and that's all." Dogfish Dissection Lab Superorder Squalimorphii *Lack anal fins *Viviparous (some ovoviviparous) *Diversity in size and form *Species have 5+ gill slits Order Squaliformes Family Squalidea Squalus acanthias Genus Squalus Species acanthias Dogfish Fishing Industry Junk fish to a regulated fishery SpinyDogFactSheet (dragged).pdf.