INDUCED BREEDING OF SILVER CARP HypOphthaimichthys moiitrix (Valenclennes) UNDER THE EGYPTIAN ENVIRONMENTAL CONDITIONS | ||
| Journal of Animal and Poultry Production | ||
| Article 12, Volume 31, Issue 5, May 2006, Pages 2787-2804 PDF (2.08 M) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/jappmu.2006.235492 | ||
| Authors | ||
| A. A. El-Gamal,; M. Abdel-Batty Amer | ||
| Fish Production Section, Department of Animal Production. Faculty of Agrlculture, Aln Shams University. P.O. Box: 68 Hadayelr Shoubra, 11241, Cairo, Egypt. | ||
| Abstract | ||
| The reproductive performance of 181 female silver carps Hypopthalmichthys molitrix (Valenciennes) was followed up during 8 months (March-October) in two successive years. 2004 and 2005 under the Egyptian environmental conditions. To study their reproductive performance. ovulation was stimulated in females with two doses of a carp pituitary powder (Argent. Philippines. Manila): a preparatory dose (0.3 rngllrg) followed by a resolving dose of 4.0 mgfkg body weight after 9 h. whilst males were stimulated with one single dose of 3 mg Ikg. Females were shipped approximately 7-8 h after the second injection and eggs were immediately fertilized "dry method“. Fertilized eggs were incubated in conical shaped fiberglass tanks supplied with aerated fresh flow-through water. An attempt was also carried out to outline the age at maturity in 214 females during 2005. The monthly trend of spawning traits in terms of percentage of ovulated females. egg weight in grams and as a percentage of female's body weight. number of seeds per kgflish. percentage of fertilized eggs, larval survival rate and percentage of defomied larvae were estimated. Highest female response to induced breeding and better larval quality were obtainable from April to June. Females of silver carp attained sexual maturity at a body weight of less than 2 kg and an age of two years old or less. The lowest percentage of spawned fish was recorded in March (66.73nd 50.0% in 2004 and 2005, respectively). During other experimental months percentage of ovulated females was in the range of 83.3 to 100%. The latency time was approximately 7.5 h at a temperature of 255°C. Stripped eggs as a percentage of female body weight (ES!) ranged from 6.87 to 15.75%. Relative fecundity of females was in the range of 51.070 and 156,440 eggsilrg. Hatching occurred after approximately 20 hours at 25.5 '0 water temperature. Fertilization and survival rates ranged from 85.91 to 97.86% and 72.72 to 80.72%, respectively. The lowest percentages of deformed larvae (11- 12%) were observed during April-May compared with either that obtained during the early season (March: 15-20%) or at the late spawning season (July-October: 16- 18%). | ||
| Keywords | ||
| silver carp. hypophysation; sexual maturity; induced breeding. fertilization rate. fecundity; 63! index; larval survival rate. percentage of deformed larvae | ||
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