Dr. Md. Fazlul Awal Mollah
Professor
Department of Fisheries Biology and Genetics, BAU, Mymensingh-2202
Mastacembelus armatus collected from different rivers and beels of greater Mymensingh district were reared in ponds of faculty of fisheries, BAU. The fish were reared as broods for 18-20 months while supplied with 35% protein rich food at 5% of their body weight. Some pieces of PVC pipe of 2-3” diameter were placed at the pond bottom for shelter. Males were comparatively large in size, dark-coloured while females were comparatively small and of light colour. Swollen abdomen was the main identifying character of female broods. In the preliminary experiments, three treatments of inducing agents were administered with two replications for each. Carp PG extract at the rate of 100, 150 and 200 mg/kg body weight were applied in case of females and the males were not treated. Milt extruded with gentle pressure but female did not extrude ova. Based on the negative results of that experiment using different doses of single inducing agent i.e. PG extract, a different approach was followed later on. HCG (Human Chorionic Gonadotropin), another inducing agent was used at different doses and PG combinations. Both PG extract and HCG were used in different combination in case of females while males were treated with only PG extract at the dose of 5 mg/kg body weight during the second dose of female. The weight of the females were 60 g, 75 g, 110 g and 130 g in treatment I, II, III and IV respectively. Males were treated with single dose and females with double dose. Stripping was performed after six hours of the second dose but no ovulated eggs were obtained. However, they were tried to extrude ova by stripping after waiting another three hours and the result was negative. The females were extremely exhausted especially larger one and was sacrificed for gonado-somatical index (GSI) and histological study. The GSI of the female was 13.23 and fecundity was 117000/kg fish. The diameter of the individual egg was 1.5 ± 0.3 mm and yellowish in colour. The size of the ova was more or less uniform. It was found that the connective tissues were not ruptured at this stage. However, trials are in hand in a little different environment from those of the previous ones. Aquatic weeds, mud and shelter will be provided and strong water flow will also be given to see the probable changes in breeding performance. However, it was recommended that an optimum dose should be established to rupture the connective tissues of the ovary. PG dose of 5 mg/kg body weight to the males produced slightly more milt than those used without treatment with any inducing agents.
Mastacembelus armatus, breeding performance, fry, larval, technique,
Faculty of Fisheries, BAU, Mymensingh,
Variety and Species
a) To develop a brood management technique of Mastacembelus armatus.
b) To develop a reliable induced breeding technique.
c) To develop a suitable larval rearing technique.
1) Brood collection and rearing.
2) Selection of brood fish
3) Conditioning of brood fish
4) Source of Pituitary gland (PG) and extract preparation
Bangladesh Agricultural University Research Progress, Volume 15,
Proceedings of the Workshop 15-16 January 2005,
Bangladesh Agricultural University Research System (BAURES), Mymensingh
Bangladesh.
225000
It was found that the connective tissues were not ruptured. Aquatic weeds, mud and shelter will be provided and strong water flow will also be given to see the probable changes in breeding performance. However, it was recommended that an optimum dose should be established to rupture the connective tissues of the ovary. PG dose of 5 mg/kg body weight to the males produced slightly more milt than those used without treatment with any inducing agents.
Report/Proceedings