TROUT CULTURE ON THE NILGIRIS. 907 



growth of grass trails over the top and affords a certahi amount of protection 

 from the sun. Artificial shade is also provided in each pond whilst the 

 " redds " are screened by a transverse layer of split bamboos. 



The two stock ponds contain fish varying from two to four and from three to 

 five years respectively. Although females of five to six years still yield ova, 

 yet it has been found that no fish will live in captivity more than seVen years. 

 The males go off sooner than the females and should be scrapped in their thii'd 

 year. " I have found that the largest and best eggs are produced by fish from 

 three to five years old." (Badminton.) An advantage of dealing with large fish is 

 that they produce more ova, the numbers given in Badminton being about 1,000 

 to the pound. Ova from immature or undersized fish may be easier to procure, 

 but will never give the same satisfaction as those from parents of proper condition 

 and age. (Howieton and Northern Fisheries Company's price list for 1918-19.) 

 On this point we are in thorough agreement with the remark of Mr. G. C. L. 

 Howell, F.Z.S., in the journal of the Bombay Natural History Society, Vol. 

 XXIV, No. 2 : — " Over six years old females still give us splendid ova, but a 

 male trout (Brown Trout) in India is at his best when one year old, and his milt 

 goes off after the third j^ear." In fact three of the oldest stock males have just 

 been scrapped and their place taken by younger males from the other pond, which 

 will in turn be replaced by wild trout. It follows from what has been written 

 above that the whole of the older stock should be replaced in the course of the 

 next twelve months by yearlings reared from the ova imported from 

 Kashmir. 



Above each of the stock ponds is a long narrow reach or ' redd ' where the water 

 trickles over loose stones, thus affording an ideal spawning ground. It is along 

 these ' redds ' that reproduction has been allowed to take place, such ferti- 

 lised ova as are required for sale or rearing being grubbed up from between the 

 stones. The loss by disturbance must be immense. It is, however, proposed 

 that in future the process of natural fertilization be supplemented by stripping 

 and the use of the dry method. 



This has been ably described by Mr. Howell : — " The eggs are carefully ex- 

 pressed into a moist basin in an adhesive mass. Milt is meanwhile collected 

 from the male fish into a dry thermos flask, is poured on to the eggs and well mixed 

 up with them by hand. An inch of water is poured into the pan and kept in 

 circular movement to prevent adhesion to the basin. After three minutes, the 

 milt is washed off." The eggs obtained from the redds or else fertilized by the 

 dry method as described above are then poured on to glass grilles in hatching 

 boxes with a gentle flow of water carefully filtered through six thickness of 

 Turkish towelling flo-wing over them. 



The use of glass grilles has by some been condemned as being antiquated. 

 They permit only a single layer of ova to be developed at a time. With perfo- 

 rated trays, several layers can be superimposed, a far larger number of eggs can 

 be dealt with and there would be economy in space and in labour. But as a 

 matter of fact there are plenty of perforated trays at. the hatchery. As natural 

 reproduction is good, the hatching boxes have not hitherto been worked to their 

 maximum capacity. When only a limited number of ova are required, the 

 grilles are preferable to the trays. The ova are more accessible on them and 

 diseased or unfertilised specimens are more easily removed. 



In 15-45 minutes the eggs separate and are left to eye. In this stage they are 

 extremely delicate. The slightest shock will kill them. Eggs which are un- 

 fertile or in which the embryo has been killed turn white and must be removed 

 daily with a glass tube. Unless taken out, they will soon infect the whole batch 

 with fungus. The eye of the fish generally appears as a dark spot after 2o days. 

 The eggs are then hardy and can be moved with comparative safety. 



It has not been the practice in the Nilgiris to plant eyed ova m natural nurser- 

 ies. Another difference between local methods and those pursued in Kashmir 

 33 



