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The Toledo Zoo/ThinkingWorks

Teacher Overview for the Lessons

2003

Teacher Overview:

Amphibians have many traits that are unique to this particular of . Below is a list of general amphibian traits to help you and your students complete the ThinkingWorks lesson.

The class Amphibia is divided into three groups or orders, each with their own set of features. The orders are and , and .

We have included a list of the different amphibians found at The Toledo Zoo by and where you can find them on exhibit. Note that animals move constantly in and out of the Zoo. Please call the Zoo for a current that are on exhibit and their locations. Wild and adults can also be observed on Zoo grounds in the formal garden area near the Conservatory. Look near the pool in the butterfly garden.

General Amphibian Traits q The cycle of an amphibian (the name means “two-lived”) begins as an . Tadpoles or larvae (singular is ) hatch from the egg. Tadpoles are an immature stage. The tadpoles then mature into adults. This process is called . q Females deposit in where they are fertilized externally by males (see diagram). q Eggs hatch into tadpoles that are aquatic (live in water), breathe through instead of , have a , no , ears and, initially, no legs.

Adult Male (Larva) Adult Female

Eggs

q Adults of most amphibians have four legs, lungs, eyelids, tear glands and ears. q Besides lungs, most adult amphibians can exchange gases through the and the membranes lining the . q Most amphibians are restricted to rather moist because their permeable skin is unable to prevent a large loss of body water in a drier setting.

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2003 Teacher Overview - Amphibians

q ventilation is not by movement of the and a diaphragm (as in ) but by movement of the floor of the mouth (you can easily observe this in an adult ). q All amphibians are cold-blooded or ectothermic; their body temperature is close to that of the environment and fluctuates with it. q Because they are cold-blooded, amphibians living in temperate regions must move during winter to areas that do not freeze, entering a dormant state know as . Amphibians bury themselves in the at the bottom of or into soft ground below the frost line. q During hibernation, the only utilized is that stored within the body; and circulation are very slow. q Some tropical amphibians during the hottest and driest parts of the go into a similar dormant state known as .

Orders of Amphibians

Order Characteristics Salamanders q Tadpoles have . q One of salamanders has no lungs; occurs through the lining of the mouth and the skin. q Some groups of salamanders (e.g., mudpuppy) live their entire life in water as a larva and metamorphosis is never completed.

Frogs and Toads q Frogs are generally more aquatic, depending on the water for food and protection (e.g., ). Frogs q Frogs have obvious webbing between the on the fore and hind feet. q Frogs have long hind legs and are powerful jumpers. q Toads do not have obvious webbing between the toes. q Toads have shorter hind legs and are Toad weak jumpers. q Toads secrete from parotid glands behind the . q Toads are more terrestrial (land dwelling). Their skin is thicker and less Digital pervious to water than that of frogs. Tree Pads Toads are crepuscular; they are most Frog active at dusk and dawn. q Tree frogs are arboreal, living in trees and shrubs. They have digital pads on the tips of the toes for gripping.

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2003 Teacher Overview - Amphibians

Caecilians

Egg mass -like q Worm or like in appearance. appearance q Legs are absent. q Confined mostly to the tropics. q Caecilians are terrestrial and aquatic.

Amphibians on Exhibit at The Toledo Zoo

Order Amphibian Location Frog and Toads Diversity of Life (DOL) Fowler’s Toad Northern Grey Striped frog Green arrow frog Building Blue poison arrow frog Surinam toad Asiatic horned frog

Salamanders Eastern tiger DOL Northern Salamander sp.

Caecilian Aquatic Reptile Building

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2003