Grass Carp Larvae Research Articles

Comparison of early developmental stages and adults of grass carp, Ctenopharyngodon idella, and hybrid carp (female grass carp × male bighead Aristichthys nobilis)

Hybrid carp and grass carp from the zygote to the prolarval stage and adults were compared to establish distinguishing characteristics. Zygote diameter, yolk sac and embryo length were not different between the fishes. Body pigmentation patterns showed distinct separation among the prolarvae of the hybrids and grass carp. Total and preanal myomeres were higher in grass carp larvae than in the hybrids. The grass carp and hybrid larvae also differed in 38% of the proportional morphometric characters.Average meristic counts of adults were significantly higher in hybrids compared with grass carp. Adults of the two fishes showed significant differences in 63% of the proportional morphometric measurements. Gill raker counts showed no overlap and lateral line scales were smaller and more numerous in the hybrid adults.

Intensive rearing of grass carp larvae Ctenopharyngodon idella (Valenciennes 1844) under controlled conditions

This paper describes an indoor feeding experiment with grass carp larvae. It was intended to identify rates of survival and growth of newly hatched larvae in a hatchery using dry feed only until they reached a size which allowed stocking in growing ponds without additional nursing. The larvae fed on Alkan yeast reached a mean total length of 10.3 mm with negligible mortality rates within a feeding period of 1 week. Problems concerning optimal feeding with dry feed and optimal stocking densities in rearing tanks are briefly discussed.