Meeting Abstract

29.1  Monday, Jan. 5  Why Are There no Giant Teleosts? LANDRY, S.O,; State Univ. of New York, Binghamton slandry@binghamton.edu

Why are there no giant teleosts? Every other vertebrate clade that has entered the ocean has produced giant forms (chondrichthyans, placodermii, reptiles, mammals), Defining a giant as above 30 feet (10 meters) and one tonne, no living teleost even comes close Largest: bluefin tuna, 14 feet, and 1496 lbs (680 kg), but among living chondricthyans; Basking shark (Cetorhinus), 11.8 meters and 17.3 tonnes; whale shark (Rhyncodon), 12.2 meters and 12.7 tonnes,), Very large acquatic animals are usually filter feeders. The characteristic operculum of teleosts covers the gills and restricts the flow of water through them All teleost filter feeders are small. On the other hand the forward position of the teleost mouth parts, restricts the size of the bite, making the attacking of large prey by large fish less feasible. The characteristic gape and suck mechanism of teleosts thus restricts their ability to take large prey.