Effects of temperature on the induced spawning of channel catfish and the production of channel×blue catfish hybrid fry

• Published in: Aquaculture 2007-11, Vol.273 (1), p.80-86
• Main Authors: Phelps, Ronald P., Hastey, Ryan, Pendetar, Alden, Linley, Laban, Papanikos, Nikolaos, Dunham, Rex A.
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal aquaculture; Animal productions; Animal reproduction; Animal, plant and microbial ecology; Aquaculture; Biological and medical sciences; Brood selection; Catfish; Channel catfish; Degree-hours; Egg quality; Fish production; Fresh water ecosystems; Fundamental and applied biological sciences. Psychology; General aspects; Reproduction; Synecology; Temperature effects
• ISSN: 0044-8486; 1873-5622
• DOI: 10.1016/j.aquaculture.2007.09.019

Hybrid catfish (channel catfish, Ictalurus punctatus, female×blue catfish, I. furcatus, male) can be obtained by induced spawning and artificial fertilization but with variable results. Temperature of the surrounding environment affects the rates of physiological processes in fish including time to ovulation following hormone injection and time post-ovulation when quality eggs can be obtained. Brood females were held at 24, 26, and 28 °C in 100 L aquaria and injected with LH-RHa at 20 μg/kg followed 12 h later with 100 μg/kg. Fish were monitored hourly recording the time of the first egg deposit. Some females were manually stripped soon after the first eggs were observed, and the remaining females were stripped 4–6 h after the first eggs were observed. Eggs were artificially fertilized with blue catfish sperm and incubated. The percent of females that ovulated were 52.9%, 82.4% and 95.5% at 24, 26, and 28 °C (P=0.001) respectively. The majority of females that ovulated did so between 58 to 64 h at 24 °C, 48 to 52 h at 26 °C and 24 to 40 h at 28 °C for a degree hour response time of 1405±117, 1141±238 and 951±261 respectively (P