97 



Rushiknlya lakes are too distant and ill placed for fishery work ; 

 Marikanave is in other territory ; hence tanks with permanent waters 

 are not very numerous, thoug-h they may hereafter be increased by 

 projects in contemplation. But such as they are, they should be im- 

 proved as food sources by direct cultivation and should not be allowed 

 merely to grow a natural crop ; at present it appears that the Kanigiri 

 and other great reservoirs are hardly utilized ; amongst the suggestions 

 which follow is one for improving the fisheries of these tanks, with 

 the view not only of making these tanks profitable, but of obtaining 

 data and displaying examples which may be followed even in tempo- 

 rary sources. Tanks with temporary water vary in capacity from one 

 month's to six or more months' supply; the fishery rights in these are 

 annually let out, usually for small sums, and the mode of fishing is, in 

 general terms, simply the netting of the muddy residue in the tank 

 shortly before the supply is exhausted. Apparently a number of fish, 

 chiefly murrel (Ophiocephalids) have the power of aestivation and, 

 escaping the drag-net, bury themselves in the mud throughout the 

 dry season ; hence a natural stock of reproductors is provided and 

 the large size of many of the fish is accounted for ; murrel, however 

 Ijeing voracious fish of prey in any case increase readily in size owing 

 to abundance of food, since tank waters are either supplied from 

 rivers in which case they probably contain abundance of fish fry and 

 other food, or they drain from the surrounding cultivation and are also 

 bathing places for cattle. From the results of Japanese practice and 

 from the few data we have of the tropical growth of carp, it is obvious 

 that tanks which usually hold water for four months and upwards 

 may often be usefully stocked, but it would be necessary continually 

 to net out the predaceous fish to the greatest possible extent. 



203. Canals. — Omitting Tan j ore and other systems there are 

 under the Kistna, Goddvari and Kurnool-Ouddapah systems alone 

 about 1,072 miles of main and branch canals, all navigable, except 

 57 miles, besides nearly 4,300 miles of the distributaries, exclusive of 

 course of field channels. The body of water contained in the main 

 and branch canals at any given moment must bo above 1,500 million 

 cubic feet, and tho volume of water lot into them during the nine or 

 ten months of flow, averages above ^00,000 million cubic feet or 

 11,000 million cubic yards. This vast body of water is probably full 

 of fish food since the rivers drain forests and districts in their course 

 while the sides of the canals provide a good deal of vegetable life and 

 consequently shelter small animal life of very rapid growth and 

 increase. What this body of water could produce cannot possibly be 

 stated even as a guess ; its total area at an average of only 60 feet 

 in width is something over 8,000 acres, but this in no way expresses 

 its productive powers, since the water is continuously changing and 

 therefore, being river water, bringing new supplies of food ; hence 



