FNR 24150 Lecture Notes - Lecture 1: Tiger Salamander, Lesser Siren, Herpetology
16 Oct 2017
School
Department
Course
Professor
Document Summary
Herpetofauna: amphibians and reptiles living in a certain geographic area. Amphibians: skin without scales, feet without claws, eggs without shells (amnion, adults lay eggs in water, eggs hatch into larvae that breathe via gills, larva lose gills and metamorphose into somewhat more terrestrial adults. Reptiles: skin with scales, feet with claws, eggs with soft shells (amnion, adults lay eggs, eggs hatch into larva that look like miniature adults, larvae mature without metamorphosis. Classification of extant amphibians: order: gymnophiona (caecilians) Least known of all living amphibians (fossorial lifestyle), they have blunt, bullet-shaped heads attached to long cylindrical, limbless bodies (worm-like: order: caudata (salamanders) Most are secretive, avoid direct sunlight, and are active at dawn and dusk (crepuscular) Typically have biphasic life cycle: fully aquatic and terrestrial variants. Spermatophore deposition of spermatozoa, female picks up with cloacal lips (fertilization can be delayed in some species) Spermatophore- mucus plugs topped with a sperm capsule. Not great swimmers, walk on bottom of streams.
