350 TROPICAL AND SOUTHERN FISHES 



An altogether aberrant section of the spiny-finned group is re- 

 Sucker-Fishes . 



presented by the sucker-fishes of the genus Echeneis, alone constituting 



the family Echineidce. In these remarkable fishes the first dorsal fin is modified 

 into a very complex adhesive disc, by means of which they attach themselves, 

 belly-uppermost, to sharks, turtles, and ships, thereby obtaining an abundant food- 

 supply without any active exertions on their own part. In accordance with this 

 reversed position the remora and its relatives have the under surface of the body 

 dark and the upper side silvery, so that any one handling a specimen for the first 

 time is almost sure to mistake the back for the belly. Out of some half-score species, 



= :".V 



GAPD SDCKER-FISH. 



one of the most widely distributed is the remora of the ancients {Echeneis remora), 

 which attains a length of about eight inches, or approximately one-fifth that of 

 the equally common E. naucrates, the gapu of the Papuans of Torres Strait. 

 These fishes are essentially denizens of the tropical seas, although when attached 

 to ships they are frequently carried into colder waters. In Torres Strait the 

 natives employ the gapu in capturing turtles ; the fish, with a line passed though 

 its gills and attached to its tail, being carried on the bottom of the canoe. When 

 a turtle is sighted, the gapu is thrown into the water and immediately makes for 

 the reptile and attaches itself to the shell. In the case of small turtles, they are 

 forthwith hauled in hand over hand, but when the gapu attaches itself to larger 



