Fish and Their Fabulous Neighbors [ 169 



Fish Use Camouflage Too 



The color of fish is often a definite camouflage, comparable to 

 protective schemes on many birds and mammals. You may see 

 a hint of protective coloration in a goldfish, as the orange tones 

 of its back fade to pale lemon-yellow below. In general, fish are 

 darker-colored on the back than on the underside. As the darker 

 color blends with the river or pond bottom, fish tend to be less 

 noticeable to an observer from above. Yet when fish feed near 

 the surface their light underparts blend with the sky, so that 

 they are not too likely to be seen by enemies swimming below. 



Perch, pike, and other species that live among weeds are pro- 

 tected by their vertical stripes. An extreme example of camouflage 

 is the "leaf fish" of the Amazon River which is colored like a 

 dead leaf and has a projection from its lower lip that resembles 

 a leaf stalk. Even its actions reinforce the illusion: In stalking its 

 prey it drifts along like a dead leaf. 



How Fish See and Hear 



"Goldie winked at me. I saw him!" my exuberant youngster 

 exclaimed one day during a close scrutiny of the aquarium. 



He was disappointed when I pointed out that a fish has no 

 eyelids and therefore cannot wink. However, fish do have eye- 

 balls and when one of these is flicked downward you get the 

 impression of a wink. The lack of eyelids also means that whether 

 the fish is awake or asleep, its eyes are wide open. 



Fish do not have keen sight. The part of the eye that takes in 

 light is round whereas in land animals it is flattened. Fish are 

 near-sighted because of the shape of their eye lens. 



"Can the fish hear us?" is another challenging thought to 

 children who enjoy talking to their charges at feeding time. It is 

 doubtful that they can, but they do seem to be awaie of hand 

 clapping or the sound of tapping on the aquarium walls. 



The fish has no outside ear or even openings where you would 

 expect to find ears. It does have other sense organs, however, 

 through which it can get some of the same impressions that we 

 receive through our ears. In fact goldfish, minnows and others 

 learn to react to whistles and certain other sounds at feeding dine. 



