88 



" lo. Experiments were carried out with the eggs and fry of 

 Ophiocephalus punctatus and O. striatus re hatching and rearing 

 under artificial conditions. 



" 1 1. It was discovered that several minute water-insects play an 

 important part in the destruction of the ova and fry under natural 

 conditions. The worst offender in this respect was found to be the 

 small water-flea Daphnia pulex. These minute insects attack and 

 destroy the fry in their early stages and the ova throughout the 

 hatching period. Frogs destroy both ova and fry, but the parents 

 who guard their eggs and young can deal with this natural enemy, 

 whereas they are helpless in the former case. 



" 12. Fishermen take advantage of this parental afTection for the 

 capture of the big fish. They locate a nest and bait with a frog which 

 they dangle in close proximity to the eggs or fry and the parent fish 

 are easily caught. The eggs or young fry are then left to the mercy 

 of all enemies and consequently very few, if any, survive out of the 

 original number in the nest. 



" 13. The experiments were to determine the following, viz : — 

 (i) most suitable hatching appliances ; 



(2) periods of hatching at different temperature ; 



(3) most suitable water temperature for producing healthy fry ; 



(4) best artificial food for rearing fry ; and 



(5) rate of growth, etc. 



" 14. These experiments are not yet complete, but a lot of useful 

 information was obtained. 



" 15. The most suitable hatching appliances were found to be glass 

 tanks where the eggs and fry can be kept under constant observation 

 and the presence of minute enemies detected at once. The water 

 temperature ranged between 76^ and 84-^ F., an average temperature 

 of 78-" seemed to be preferable. Various artificial foods were tried, 

 the most suitable for the very early stages (just after absorption of 

 the yolk sack) seemed to be the soup of crushed crab. 



" 16. Notes on the periods of hatching rate and growth of fry were 

 taken together with specimen fish carefully preserved at various 

 stages. 



" 17. Before any work can be published on the artificial hatching 

 and rearing and most suitable appliances for dealing with these 

 particular fish, it will be necessary to carry out further experiments 

 and this will be done in due course " 



Many thousands of murrel fry were removed from the Sunkesula 

 farm during the year and turned into Edurur swamp for growing 

 purposes. Large numbers of the quick-growing varieties of carp from 

 the farm were distributed over 60 miles of the Kurnool-Cuddapah 

 Canal. Great difficulty of rapid transport is found and I am afraid 

 to transport fish below the locks to Nandyal, Ayyavankodur and 

 Kanala tanks would take too long with the present methods and they 

 will have to rely for the present on the extra fish from the upper 

 waters. The motor-boat unfortunately was found not powerful enough 

 for this work. 



* * * * 



During the year under review a new and valuable larvicide 

 Poly acanthus cupanus was transported from the West Coast (Cochin) 

 to the Sunkesula fish farm for breeding and distribution purposes. 



