MNS 307 Lecture 20: Nekton - Swimmers
Document Summary
Squid, other cephalopods, large shrimp, and some crabs. Relatively few invertebrates belong to the nekton. Few reptiles are found in the ocean. 50 kinds in the pacific and indian oceans. 80% of sea turtles in us are in florida. Live in ocean but nest on land. Hawksbill turtle - tropical areas, hunted for shell. Loggerhead - lots in the gulf of mexico, fl, east coast - eat cabbage head jellies. Leatherback - largest (up to 2000 lbs), dives up to 3000 ft for jellyfish. Marine species = 3% of 10000 species of birds. Vision well developed for catching fish - big eaters. Hearing not well developed (some have good smelling) Many float well because of light bones, air sacs, and fat. But cormorants/penguins have heavy bones because they swim underwater for food. Migrates 10,000 miles from antarctica to labrador. All in southern hemisphere, antarctic to galapagos. Toothed whales (dolphins), sea lions, some baleen whales use.
