THE MADRAS AQUARIUM. 
629 
Another old resident is a very large Cat-fish, Plotosus canius, that has a great 
attraction for visitors because of his superlative ugliness. An allied genus, 
Arius, is also often shown in the tanks and is perhaps even uglier than Plotosus ; 
a point of interest in certain species of Arius is that the male has the curious 
habit of receiving the eggs, as extruded by the female, into his mouth where 
he retains them till the yoimg hatch out. As the eggs are particularly large, 
about half an inch in diameter, the number that he can care for is limited. The 
eggs completely fill his mouth, so the poor father has to abstain from feeding 
till his family is born, and able to swim away. 
Of fresh-water fishes, the nest-building murrel and gourami find a home in the 
central floor pool, while a table tank accommodates examples of the curious 
climbing jierch Anabas scandens, called in Tamil by a descriptive name that 
translates into “ the Perch that climbs Palmyra palms ” ; in another are sho^vn 
scores of the little fishes Haplochilus melanostigma and Panchax parvus, that 
are now being bred in thousands by the Fisheries Department for the purpose 
of destroying mosquito larvae in ponds and pools. These are supplied at low 
rates to public bodies interested in combating the malaria scourge ; when 
properly cared for, these fishes thrive and multiply prodigiously and subserve 
this mosquito -larvae destrojdng purpose admirably. 
One tank is given up to various species of sea-snakes abundant in the sea off 
Madras. This exhibit has very great attraction for visitors, who look with awe 
on these super-poisonous creatures, possessing venom several times more deadly 
than that of the cobra. Actually they are most inoffensive creatures, except 
towards fish on which they prey, or in the rare case of being trodden on by some 
incautious foot. The attendants do not fear them nearly so much as they fear 
the pretty harmless-looking Pterois russelli. And there are always a few small 
sea-perches in the same tank that unconcernedly snatch fragments of meat 
from amid the wi-ithing coils of these snakes at feeding time. 
Little accommodation is available for other exhibits than fishes, but usually 
some of the more curious crustaceans and molluscs of the district are represented. 
Among the former are the spiny Crawfish (Pannlirus), various swimming crabs 
such as the blue-limbed Neptunus pelagicus, the three spotted N. sanguinolentus, 
and the strange little Dorippe dorsipes, camouflaging itself by holding a bivalve 
shell over its back with the aid of the two last pairs of legs that have been modi- 
fied specifically for this purpose. Of Molluscs, examples of the Sacred Conch, 
Turbinella pirum, and various spiny Murices are often present, together with 
small examples of the Octopus of a species caught in thousands by the fishermen 
of Palk Bay in curious shell traps, tied in large numbers on long lines laid in 
shallow water. 
