Introduction Flashcards
Class Amphibia contains what three clades? Describe each clade.
Gymnophiona - Caecilians. Legless, burrowing amphibians found in wet, tropical areas. Resemble earthworms.
Caudata - Salamanders. Includes sirens (eel-like), basal (primitive) salamanders, and derived salamanders (axolotls, newts, and many terrestrial species)
Anura - Frogs.
Describe salamanders and newts.
Salamanders have lungs and numerous poison glands in skin.
Newts can have an aquatic larval stage, terrestrial juvenile period (efts), and aquatic adult stage.
The family Pipidae contains what frogs?
Xenopus laevis (xenopus genera) and X. tropicalis (Silurana)
What family do toads belong to? What are characteristics of toads?
Bufoniade.
Warty, thick skin with a well-developed parotid glands. Males have a Bidder’s organ (ovarian tissue located on cranial pole of testis)
Define aposomatism.
Bright color patterns alert would-be predators to the presence of highly toxic alkaloid skin secretions.
How do poison dart frogs produce their poisons?
Alkaloid secretions derived from wild diets of arthropods and greatly reduced in captive frogs eating typical fruit fly and springtail diets.
What frogs belong to the family Ranidae?
“True frogs.” Rana/Litohbates, including L. castesbeainus (bullfrogs) and L. pipiens (northern leopard frog).
How does the tympanum of Ranidae frogs differ by sex?
Larger than the eye in males, similar to eye diameter in females.
How was X. laevis initially used in research?
Pregnancy assays - Injection of a pregnant woman’s urine into the dorsal lymph sac of a female frog caused the frog to begin laying eggs.
Why is Xenopus popular among developmental biologists?
Ability to reproduce year-round when injected with commercially available hormones.
Currently, what are Xenopus laevis most commonly used for? What does FETAX stand for?
Cell and molecular biology research. Frog Embryo Teratogenesis Assay: Xenopus.
What are advantages to the use of X. tropicals in research?
Small genome (10 chromosomes) and short generation time.
What is the scientific name of the axolotl? How are axolotls and newts unique?
Ambystoma mexicanum. Regenerate limbs, tail, jaws, skin, spinal cord, brain, and heart apex.
What species do Ranidae frogs (bullfrogs and leopard fronts) belong to? What are they used to research? Why?
Lithobates. Antiemetic work due to ability to regurgitate easily.
Where should amphibians be sourced from?
Captive populations, or wild populations of invasive species.
