No. 5 (1921) MADRAS AQUARIUM 67 



this habit of attaching to any large animal within its reach, even 

 to a larger individual of its own species if this be the biggest fish 

 in the tank. The habit has been acquired probably to enable it 

 to gain its daily bread with the minimum of exertion. In other 

 fishes (some of the gobies) a sucker is similarly formed by the 

 modification of the ventral fins. In this case the use is not to 

 facilitate transport without effort, but conversely to prevent 

 being carried away by a strong current or the backwash of the 

 surf. These particular gobies are but tiny fishes and have not 

 the strength to withstand the force of water without the help of 

 a specialized organ. 



Our common species of Remora is banded longitudinally on each 

 side with two conspicuous white bands enclosing a median dark 

 stripe. Like many other fishes it has the power of suppressing 

 or changing certain colour markings at will, and for a few minutes 

 the white stripes along the sides often disappear. 



A fish of quite a different family is sometimes mistaken even 

 by fishermen for the common remora. This is the Buttcrfish, 

 Elacate nigra (Tam. Kadal viral). It has the same white bands 

 enclosing a dark one along the sides and the slender form of the 

 body adds to the resemblance. But it has no sucker and its habits 

 are totally different. Instead of a picker-up of crumbs from rich 

 men's tables, it forages for itself and its name of kadal viral well 

 describes its predatory nature and savage instincts. 



TANK No. 3. 



Among a crowd of pretty fishes in this tank, the palm of beauty 

 must be given to one of the Butterfly fishes {Hoiiochns macrolepi- 

 dotiis) (Tam. Sadakkan). Its bold black and white banding and 

 yellow fins arrest the attention. The dorsal fin carries a long 

 yellow streamer often missing however, as it is too tempting to 

 other fishes, who generally bite it off. Heniochiis though slow 

 moving is of a vicious nature and plays the bully towards the 

 wounded or sick. A number of Apogoii aureus, the marine goldfish, 

 were at one time in this tan'<, and as these fishes are very suscep- 

 tible to " gas-eye," one after another developed this ailment; no 

 sooner did the eyeball protrude, than one or more of the Hcniochns 

 made an onslaught and plucked it out, afterwards attacking other 

 parts of the body. 



Another interesting fish here is the Pearl-spot, Etroplus siiratensis 

 (Tam. Seththa-kendai). Although smill, it is likely to have great 



