Tank Acclimation and Induced Spawning of the Catostomid, Black Buffalo

Abstract

The Black Buffalo Ictiobus niger is a deep-bodied, riverine species that has experienced population declines similar to many other catostomids. Captive propagation is an important component of conservation for declining species, although there is little known about induced spawning techniques for catostomids. Developing culture techniques for Black Buffalo, including tank acclimation and induced spawning, are potentially beneficial for conserving other catostomids as well. Therefore, we examined tank acclimation and induced-spawning methods in three separate spawns over 2 years. Acclimation was aided by cool temperatures (~15°C), low salinity (3.0‰), and light-reducing covers for 2.5 weeks after which temperature was increased from 15°C to 23°C by 1°C/d over 8 d. Females (n = 23; TL = 641 ± 12 mm [mean ± SE], weight = 4,773 ± 299 g) were injected with the gonadotropinreleasing hormone analogue (GnRHa), and 7 of 23 ovulated (30.4%) with a mean fertilization percentage of 41.5% (SE, 7.1%). Large fish and fungal growth on incubating embryos provided logistical challenges, further indicating the importance of minimizing stress during tank-holding procedures. This study outlines effective tank acclimation procedures and demonstrates that Black Buffalo can be induced to spawn with GnRHa.

Zooplankton Selectivity by Black Buffalo in Fertilized Ponds

“…Larval Black Buffalo used in this study consisted of F 1 offspring from wild broodstock that were induced to spawn via the methods of Guy and Allen (). Wild broodstock were purchased from a commercial fisher in Greenville, Mississippi, and were confirmed by phenotypic characteristics, including a subterminal mouth, a rounded predorsal region, and a TL : body depth ratio greater than 2.9 (Ross ).…”