Page 10 - Fish and Amphibians (Britannica Illustrated Science Library)
P. 10
General Characteristics CROCODILE FISH FIN EARLIEST FORMS 8-9 CARTILAGINOUS FISH 14-15
This fish, which lives in
waters with abundant coral DISTINGUISHING FEATURES 10-11 ANATOMY 16-17
reefs, can grow up to 21 BONY FISH 12-13
inches (54 cm) long.
ish were the first vertebrates fish, the earliest fish had no scales, fins, water and salt water. Their bodies are these complex creatures normally
with bony skeletons to appear or jawbone, but they did have a type of generally streamlined, being covered breathe through gills that capture
on the Earth. They doubtless dorsal fin. Over time they have been with smooth scales and having fins that oxygen dissolved in the water, and they
form the most numerous group changing in form and size to adapt to enable them to move with energy, are cold-blooded.
F of vertebrates. Unlike today's different environments, in both fresh direction, and stability. In place of lungs,
