(American bullfrog – Rana catesbiana) Phylum Amphibia (American bullfrog – Rana catesbiana)

Froggy Classification Phylum – Chordata Sub-phylum – Vertebrata Class – Amphibia Super-order – Anura (meaning “without tail”) Order – Salientia (includes frogs and toads) Family – Ronidae Genus – Rana Species - catesbiana

The Orders Amphibia: 1. Anura – examples are frogs & toads 2. Caudata – examples are salamanders & newts 3. Apoda – examples are caecilians Amphibians are significant because they represent the most primitive vertebrates with four limbs that maintain a terrestrial niche.

3 Examples of the order Anura There are about 3500 species of frogs and toads. Frog: Habitat – temperate and tropical climates around the world Niche – insectivores (eating a diet of insects)

3 Examples of the order Anura, cont’d Toad: Characteristics – can secrete poison on their skin; appear to have dry, wart-covered skin. Habitat & Niche – generally same as frogs; perhaps somewhat more terrestrial.

3 Examples of the order Anura, cont’d Salamanders / newts: Characteristics – also have poison glands; have tails and largely cartilaginous limbs Habitat – live near water, under moist rocks and logs Niche – same as frogs and toads

General Characteristics Have no nails or claws Minimal number of teeth Most have a tongue that is projectile and sticky Spends first stages of life in water as tadpoles They go through drastic changes during development (caused by changes in hormones) Tadpoles are herbivorous while adults are carnivorous

General Characteristics Cont’d They are ectotherms. During extreme environmental conditions they either hibernate (winter) or aestivate (summer). Temperature regulation is mainly behavioral They breathe through poorly developed lungs and moist skin.

Amphibians – Systems Well developed brain attached to the dorsal nerve cord. They contain a well developed muscular system. Sensory receptors located all over the skin Good vision since these animals are mainly vision feeders; that is, they have to use their sight to find and capture food (think of a frog going after a fly!)

Amphibians – Reproduction & Reproductive System Dioecious – 2 different sexes very similar in structure (appearance) External fertilization in moist environments. Exceptions to the external fertilization are salamanders (only about 10% are external). Jelly-like eggs need to be laid in water Interactions between internal (largely hormonal) controls and extrinsic factors determine the timing of reproductive activities. Their offspring develop through a process called metamorphosis.

Vocalization Sound production is primarily a reproductive function of male anurans. These calls attract females to breeding areas and to announce to other males that a given territory is occupied. These calls may also cause some hormonal changes internally to occur, reading the breeding process in females. Sounds are caused by air being forced from the lungs over the vocal cords and cartilages of the larynx, causing them to vibrate.

Our Dissection Froggy The American bullfrog – Rana catesbiana Typically the specimens are adult male and egg-bearing females, measuring about 7 inches from the tips of their snouts to the ends of the trunks. Their long hind legs, when extended, add another 8 inches to their total length of 15 inches. Arteries are injected with RED latex, and veins with BLUE or YELLOW latex. Frogs shown good organization of systems, along with a relatively complete muscular and skeletal system.

Special Amphibian Facts Amphibians have a “double life” because they spend half their life in water and half on land. In PA waters, the presence of tadpoles and frogs show signs of good environment health.