<ul><li>A tadpole’s circulatory system has a single loop & a heart with 2 chambers, like a fish. </li></ul>
Attributes of amphibians frogs & toads salamanders eggs fertilized externally internally how obtain food wait for prey to come close (use camouflage) actively stalk & ambush prey movement 1. powerful hind leg muscles 2. skeleton that can absorb shock of landing crawl
reasons for decreasing amphibian populations <ul><li>habitat (specific environment in which an animal lives) destruction </li></ul><ul><li>poisons in environment- </li></ul><ul><li>insecticides pollute water </li></ul><ul><li>weaken adult </li></ul><ul><li>kill eggs </li></ul><ul><li>deform tadpoles </li></ul>
Golden frogs are rarely seen anymore in their native habitat —the rain forests of Panama. What are two possible causes for the decrease in the number of golden frogs?
Discharge contaminated with coal combustion wastes. Bullfrog tadpoles raised in a control habitat (A) and in an area contaminated with coal combustion wastes (B & C). Vitamin A compounds in lake water may be at least partly responsible for frog deformities. Effects of toxins in the environment Deformed frog photos