HABITS, BREEDING, ETC. 201 
under water and prevented from reaching the surface, 
they quickly become drowned, especially if they are 
excited and moving much about. When remaining 
quiet, they seem to be able to keep under the surface 
a long time ; perhaps at such times their gills are able 
to supply them with sufficient oxygen from the 
water, but when active they are obliged to come 
constantly to the surface. 
Many kinds of fish do well in tanks, and will grow 
to a large size. 
The species best adapted for this purpose seem to 
be the Boho, “ Labeo Bohita,” “ Catla buchanani,” 
“ Cirrhina mrigala,” 11 Barbus sarana,” and some 
others. The Murrul, u Ophiocephalus marulius,” 
grows to a large size, but it is a predaceous fish 
and will not get on with the other kinds. The same 
may be said of the large siluroids. 
In stocking a pond, it is said to be the best plan 
to keep in it one species only, selecting a species 
that will grow to a large size. The Catla is perhaps 
the best for this purpose, as it is quick of growth 
and of first-rate quality as food. Besides this, there 
may be other fish of small kinds, but care should 
be taken to exclude all carnivorous species. 
It should not be forgotten, however, that continuous 
interbreeding among the same stock is injurious. In 
old fish ponds it often happens that the fish get 
diseased from this cause, hence care should be taken 
to introduce fresh stock occasionally from a different 
locality. 
