268 UNDERWATER GUIDE TO MARINE LIFE 



Fig. 149. This scrawled filefish, Alutera scripta, measured about eighteen inches. It 

 has a very large tail fin which it keeps folded, propulsion being accomplished by 

 means of sine waves travelling rearward in the dorsal and anal fins. 



especially over eelgrass-covered sand, but Crawford and Powers (1953) report 

 that they sometimes school several miles offshore. The resemblance to plant 

 leaves is striking, and groups of these fishes have been observed to form a 

 rosette pattern with the head of each fish pointing inward, accentuating the 

 resemblance to floating seaweed. The young are frequentlv found in sargasso 

 weed or among other floating objects. 



Similar Species: There are several smaller filefishes on North American coasts. 

 The common filefish, Monacanthns hispidns, is most common in eelgrass and 

 can change its color to match its environment— mottled green in eelgrass, brown 

 in sargasso, pale gray over sand. It reaches 10 inches and is found from the West 

 Indies as far north as Maine. 



The scrawled filefish, Alutera scripta Qfig. 149^, is a large species, reaching 

 3 feet in length, which is found very widely in tropical seas of the world. It has 

 a concave profile to the snout, is covered with light blue and small black spots, 

 and has a very long tail which is usually kept folded. This fish is verv curious 

 and, like the ocean triggerfish, swims slowly around and around the swimmer 

 up to a distance of about 10 feet, never seeming to satisfy its curiosity. It keeps 

 to rather open waters over hard bottoms. 



The unicorn filefish, Ahitera monoceros, reaches a length of 2 feet and is cos- 

 mopolitan in warm seas. It looks much like the scrawled filefish, but has a convex 

 profile, mottled body, and shorter tail. 



TRUNKFISHES: Family Ostraciidae 



These little fishes have resorted to the same means of protection as have the 

 turtles, that of enclosing almost the whole bodv in a shell. The shell is com- 

 posed of fused, six-sided, bony scales, and it is usuallv triangular in cross section. 



