As stated before, the expert's arrival in Rangoon was quite late for the induced breeding work since the fish breeding season in Burma was practically over. However, almost immediately after arrival, the expert started his work at the Hlawga Fisheries Station situated 14 miles from the city of Rangoon.
Fish were examined from ponds previously stocked with major carp breeders. The majority of the breeders had completely resorbed their gonads, and even the roughness in the pectoral fins in most of the males had disappeared. Luckily, however, one female rohu (Labeo rohita) in fairly good condition was obtained. As no freely cozing (running) male was available, one male, though not in an ideal condition, was selected for the experiment. The pair were injected with fish (homoplastic) pituitary hormones. The female ovulated successfully releasing about one million eggs. Only a small percentage, however, were fertilized and these died in the course of development, probably because of over-congestion in a small hapa with innumerable unfertilized eggs resulting in depletion of oxygen. Further attempts to collect suitable breeders here were unsuccessful.
Twante Farm was next searched for breeders but at this farm also, the gonads had been resorbed in most of the breeders examined. Only one female Labeo gonius and two female Labeo pangusia with egg-distended abdomens were collected. No oozing males could be caught. The breeders were transported to Hlawga Fish Farm where a male specimen of Labeo rohita in fairly good condition was available. The female Labeo gonius died after injection, and her ovarian eggs when examined were found to be in the process of resorption. One of the two Labeo pangusia also had gonads in the resorbing stage. The other one was in fairly good condition.
In the absence of a male of the same species hybridization was tried. The female Labeo pangusia was injected with pituitary hormones and when the fish was ready for stripping, the eggs were stripped into a plate and fertilized by sperm from an injected male Labeo rohita. A second lot of eggs was also artificially fertilized by milt from a male Cyprinus carpio. The development of the hybrid eggs proceeded normally till the embryonic streak was formed, but curiously enough, development then stopped in all eggs whether kept in trays in the laboratory or in hatching hapa in a pond. The experiments had to be stopped because no more breeders were available.
However, despite these difficulties, it was possible to give thorough training to the counterpart officer and other co-workers on the various operations in the technique of induced breeding of carps by pituitary hormone injections, including the collection and preservation of pituitary glands, method of recording weight of glands, preparation of gland extracts, rearing and selection of proper breeders, identification of sex, calculation of correct dosages, method of injection and hatching techniques. Training was also given in and demonstrations made of methods of artificial fertilization of carp eggs and hybridization.
