No. 5 (1921) 



MADRAS AQUARIUM 



83 



eye-power of the owner. So, little by little, the still plastic bones 

 of the orbit on the lower side twist round till they come to face 

 upwards, taking the eyeball with them. Nothing of this kind takes 

 place in the equally flattened Ray-fishes, for there the flattening is 

 from above, causing the si'ics of the body to spread out like wings, 

 whereas in the Flat-fishes proper, the compression is from side to 

 side, and so if the fish has to lie prone on the bottom it must be 

 lying on one side or the other. It seems immaterial which side 

 shou'd be downwards; whichever it may be, usually it loses all 

 pigment, while the upper one develops it of such tints as afford the 

 fish almost perfect concealment. 



The true Mullets (Tam. Madavai kendai) are handsome fish of 

 great value to man, as they abound particularly in backwaters and 

 estuaries. They are largely vegetarian in diet, browsing on green 

 weed and conferva. They can live and thrive where other fishes 

 would starve and hence fill a complementary role in the stocking 

 of estuarine fish ponds. Several species are also tolerant of 

 change to fresh-water and we are now utilizing these species for 

 the stocking of tanks within reach of the backwaters and tidal 

 rivers where their fry abound in myriads at certain seasons. They 

 are pretty fishes in their quaker-grey tints. The scales are compa- 

 ratively large and the snout is peculiarly broad and flattened, an 

 adaptation to their browsing habits. 



Fig. 16. — A common Schnapper {Luiiaims Utnnlatus), 



Several Sea-perches of the common genus Lutianus are also 

 accommodated here, and, like their relatives in tanks Nos. 5, 6 and 

 8, show perhaps greater intelligence and observation in matters 

 relating to the feeding arrangements than any other fishes in the 



