Location: Warmwater Aquaculture Research UnitTitle: Pre-spawning carotenoid fortified diets improve reproductive traits of channel catfish, Ictalurus punctatus and subsequent progeny performance Author
Submitted to: Proceedings of the 40th US-Japan Aquaculture Panel Symposium ‘Hatchery Technology for High Quality Juvenile Production’
Publication Type: Proceedings
Publication Acceptance Date: 8/25/2013
Publication Date: 2/1/2014
Citation: Chatakondi, N.G., Li, M.H., Peterson, B.C., Booth, N.J. 2014. Pre-spawning carotenoid fortified diets improve reproductive traits of channel catfish, Ictalurus punctatus and subsequent progeny performance. Proceedings of the 40th US-Japan Aquaculture Panel Symposium ‘Hatchery Technology for High Quality Juvenile Production’. 40:16-22. Interpretive Summary:
Technical Abstract: Availability of consistent number of ovulatory competent channel catfish females is a pre-requisite for efficient production of channel catfish ' x blue catfish, I.furcatus ') hybrid in hatcheries. Raising hybrid catfish in production ponds enables the catfish farmer to harness improved growth rates, survival and feed conversion to improve production. Even though hybrid catfish production has been steadily increasing, fingerling production is still insufficient to meet the demand. Hybrid catfish embryo production involves hormone-induced spawning of channel catfish, stripped eggs are fertilized with blue catfish sperm, and fertilized eggs hatched in troughs in the same manner as channel catfish in hatcheries. High quality broodstock maturation diets are an essential key for successful and sustainable production of hybrid catfish fry from hatcheries. Carotenoid fortification in brood fish diets has been suggested to improve maturation and egg quality in all aquatic animals. However, fish and crustaceans are unable to produce astaxanthin de novo, only plants and protists are capable of synthesizing carotenoids. A 10-week pre-spawning broodfish nutrition study was conducted 2 months prior to spawning in twenty 1.5 m diameter, 760 L plastic tanks supplied with recirculated pond water and continuous air. Each tank was stocked with 10 fully mature 4-year old ‘Delta’ strain of female channel catfish per tank. This study was conducted to assess the effect of carotenoid fortified diets on reproductive performance of channel catfish during the pre-spawning phase. Four carotenoid fortified diets were prepared by mixing the required quantity of carotenoid in water and sprayed on a 35% protein commercial catfish feed in a concrete blender, followed by a coating of menhaden oil. The carotenoid treatments were: 1) 50 mg/kg Astaxanthin; 2) 100 mg/kg Astaxanthin; 3) 25 mg/kg of Lutein and 25 mg/kg of Zeaxanthin; 4) 50 mg/kg of Lutein and 50 mg/kg of Zeaxanthin and 5) control diet that was sprayed with the same quantity of water and oil. Four tanks were randomly allocated to a treatment. Broodfish fed 100 ppm of Astaxanthin fortified feed had a higher (P < 0.05) percent of gravid females suitable for hormone injection compared to other treatment groups. Gravid females from all the 5 treatments were subjected to hormone-induced spawning procedures to produce hybrid catfish fry in two spawning trials. Percent of females ovulated in response to hormone injection, fertility and hatching success did not differ (P > 0.05) among the treatments. However, ovulatory index, fecundity, and fry produced per kg of female were higher (P<0.05) in broodfish fed 100 mg/Kg of Astaxanthin fortified feed during the pre-spawning phase. The results of the present study suggest that supplemental 100 mg/kg astaxanthin in broodfish diet not only improved fecundity, quality of eggs and fry production, but also enhanced the physiological response of broodfish to induced spawning. Further, progeny derived by Astaxanthin fortification in brood fish diet had a positive effect on growth, increased resistance to ESC disease challenge and had a reduced stress response to low dissolved oxygen.