|
|
|
|
|
Ayinla, O.A.; Nwadukwe, F.O.. |
The effect of season on the controlled propagation of C. gariepinus was investigated. The hypophysation of C. gariepinus using the pituitary extract from the sacrificed C. gariepinus was carried out from July, 1987 to June 1988. The female broodstock weight ranged from 0.50kg while the male weight, from 0.5kg to 0.6kg. The condition factor of the female broodfish was more or less uniform (1.3 to 1.7). The results showed that there was peak production of eggs by the female during the rainy season. Eggs production for rainy season ranged from 28,000 eggs/kg body weight in June to 37,600 eggs/kg body weight in August. The percentage hatching of the fertilized eggs was also higher in the rainy season than the dry season. The highest hatching of the... |
Tipo: Report |
Palavras-chave: Aquaculture techniques; Aquaculture development; Aquaculture techniques; Http://aims.fao.org/aos/agrovoc/c_28992. |
Ano: 1990 |
URL: http://hdl.handle.net/1834/2436 |
| |
|
|
Nwadukwe, F.O.; Ayinla, O.A.. |
Weekly spawn and hatching rates of Clarias gariepinus and Heterbranchus longifilis were determined in earthen ponds during the rainy and dry seasons. There was a significant increase in spawn weight from the 2nd to the 7th week after stocking C. gariepinus brood fish (p<0.05). In H. longifilis; the increase in spawn weight was significant from the 4th to the 9th weeks (P<0.05). A positive correlation was found between spawn weight and female broodfish weight from the 4th to the 9th weeks for both species. The best hatching rates were obtained during the 7th week for C. gariepinus, and in the 8th week for H. longifilis. Rainy season trials gave better results in both species than in the dry season, while only C. gariepinus produced hatchable... |
Tipo: Report |
Palavras-chave: Fish culture; Fish culture; Http://aims.fao.org/aos/agrovoc/c_2918. |
Ano: 1993 |
URL: http://hdl.handle.net/1834/2205 |
| |
|
|
Ayinla, O.A.; Nwadukwe, F.O.. |
The larvae of clarias gariepinus were reared in 3 plastic pools at the stocking dencity of 194.25 fry/m2 with different rates of water exchange an plankton growth for each pool. The fry(6.2mm length) in each plastic pool were fed with supplementary diet of milk powder/egg yolk suspension in the ratio of 1:1 which was replaced with fish meal paste after 8 days of rearing. After 20 days of rearing the fry in the pool with the most plankton bloom and pebles on the bottom, had the lowest motality and maximum total length of 30.4+- 7.8mm. Pleurococcus sp, Navicula sp were found to be in highest concentration in the pool where the best growth pattern was recorded |
Tipo: Report |
Palavras-chave: Aquaculture development. |
Ano: 1988 |
URL: http://hdl.handle.net/1834/1279 |
| |
|
|
|