Controlled Spawning of White Catfish, Ictalurus catus, and Brown Bullhead Catfish, Ameiurus nebulosus, Using Carp Pituitary Extract and LHRHa

Abstract

If successful artificial spawning techniques can be developed, white catfish, Ictalurus catus, and brown bullhead, Ameiurus nebulosus, may have the potential to become model organisms for accelerated catfish genetics research due to their putative shorter maturation times and smaller handling size. Carp pituitary extract (CPE) and luteinizing-hormone releasing-hormone analogue (LHRHa) are two hormones used for successful spawning in commercially important channel catfish, I. punctatus, and blue catfish, I. furcatus. CPE injection, liquid LHRHa injection, LHRHa ethylene vinyl acetate copolymer (EVAC) implant, and LHRHa cellulose acetate (CA) implants were used for spawning trials in white catfish, while CPE injections and liquid LHRHa injections were used for spawning trials in brown bullheads. In 2010, LHRHa EVAC implants in domestic white catfish resulted in near-simultaneous ovulation for 100% of the females after 72 hours (1944°-hours). In 2011, LHRHa cellulose acetate implants yielded no ovulation for wild white catfish, while CPE injections resulted in 28.6% ovulation. In 2012 wild white catfish injected with liquid LHRHa did not ovulate. Water flow appears to play a key role in successful spawning as CPE injected wild-acclimated and 1- year- old domestic white catfish, both for which water flow was interrupted, were the only white catfish treatments able to spawn (50% ovulation;1550°-hours and 75% ovulation;1211°-hours, respectively). Brown bullheads did not ovulate in response to any LHRHa treatments across years. In 2012, all wild-acclimated brown bullheads given a CPE treatment with interrupted water flow were able to ovulate (<2100°-hours). All other brown bullhead treatments with CPE and liquid LHRHa injections and with continuous water flow did not ovulate. Domesticated white catfish were capable of spawning at 1 year of age. This early maturation time makes them a candidate for accelerated catfish genetics and xenogenesis research.