Hormone-injected gravid channel catfish held in individual mesh bag reduces handling stress and improves reproductive performance in hatcheries

Authors: Chatakondi, Nagaraj

Submitted to: Global Aquaculture Advocate
Publication Type: Trade Journal
Publication Acceptance Date: 10/31/2014
Publication Date: 11/15/2014
Citation: Chatakondi, N.G. 2014. Hormone-injected gravid channel catfish held in individual mesh bag reduces handling stress and improves reproductive performance in hatcheries. Global Aquaculture Advocate. 11(12):68-70.

Interpretive Summary: Hormone-induced spawning is the reliable method to produce channel x blue hybrid catfish in commercial hatcheries. However handling stress associated with induced spawning for selecting, crowding, weighing, injecting and repeatedly checking for ovulation is stressful, and these stressful processes impair reproductive performance. This study evaluates the strategy of holding hormone-injected gravid channel catfish females suspended in individual mesh bags during latency as a stress reduction strategy. This method reduces the handling stress, improves reproductive performance of channel catfish in channel x blue hybrid catfish fry production. This method also facilitates the identification of ovulating females with minimal disturbance to the fish. This method increased the hatching success by 7.4% and 18% higher fry production per kg body weight. Eight of the 10 commercial catfish hatcheries have adopted this improved method to improve the hatching efficiency by 10 - 15% and also appears to have improved the survival of post-spawned broodfish.

Technical Abstract: This study compared holding hormone-injected female channel catfish in soft-mesh bags to communally held hormone-injected female catfish in a tank as a stress reduction strategy to improve reproductive performance. Fish held in tanks were crowded, handled multiple times to record weight prior to hormone injections, and checked periodically for ovulation. Fish held in marked bags were injected through the bag, and the presence of ovulated eggs on the bag signaled the fish’s readiness to strip spawn. Although this strategy did not improve percent ovulation, fecundity, or percent fertilization of stripped eggs, it did improve percent hatch of fertilized eggs and the number of fry produced per kg bodyweight of females. This technology has been adopted by eight of the ten catfish hatcheries engaged in producing hybrid catfish fry.