Chapter 29, Problem 18STP

Summary Introduction

To write:

About the different jaws found in the fish

Introduction:

Most fishes have jaws. The development of jaws allowed fishes to prey on a larger range of animals. This included being able to prey on fish that was larger in size and more active. Fishes grasp prey with their teeth and quickly crush them using powerful jaw muscles. Jaws also allow for a biting defense against predators.

Explanation of Solution

Fish mouths come in a range of sizes, shapes, and orientations, each of which says a lot about where and what the fish eats, and about their behavior. In general, marine fish have the largest mouth, frequently possessing long, sharp teeth. Most species have jaws that can be extended which enable the fish to reach their food morsels as they swim. Other species have specialised mouthparts which allow algae to be rasped off rocks and branches. In addition, fish have teeth in the back of their mouths, almost in their throats.

If the lower jaw is longer than the upper jaw then that kind of fish feed on the surface. They lie in wait for the prey to arrive above them, and then unexpectedly strike from below.If both a fish's jaws are the same length then those fish with this type of mouth are usually mid-water feeders; however, they can feed at any spot.If the lower jaw is shorter than the upper jaw, and the jaw is often protrusible, then such fish are usually feeders from the bottom and often have barbels that help find food particles.

Conclusion

Most of the fish are predators but their prey's nature as well as how they consume it differs from class to class as well as within classes.