摘要
Understanding the relationship between fish parental age and offspring performance over their life cycle is crucial for aquaculturists.This study investigates the effect of parental age for both 1-and 2-year-old fish on the growth and survival rates of their larval to grow-out stages for two wild and domesticated strains of bighead catfish(Clarias macrocephalus).Fish were sampled from the Vietnamese Mekong Delta where wild adult fish were collected from a conservation area in Ca Mau Province and domesticated fish were taken from a hatchery in Can Tho.Four offspring treatments of 1-and 2-year-old broodstock strains were reared for 3 successive periods:40 days for fingerling rearing in static tanks with water exchange,60 days for juveniles,and 90 days for grow-out in recirculating systems.The final weight of fish at 190 days varied from 96.7 to 144.7 g.The growth of offspring was not affected by parental age(P>0.05),over the 3 rearing periods.However,the domesticated fish strain showed significantly better growth rates than the wild fish strain(P<0.05).Feed conversion ratios were comparable across fish treatments.Survival rates did not differ at the fingerling(21.8%-36.4%)and juvenile(69.0%-73.3%)stages.However,significant differences were found at the grow-out stage(69.3%-84.0%),with offspring from 2-year-old parents of both strains having greater survival rates.Overall,1-and 2-year-old fish appear to be suitable for bighead catfish breeders.
基金
This study was funded in part by the Can Tho University Improvement Project VN14-P6,supported by a Japanese ODA loan.
