Theses and Dissertations


Name: Hastey, Ryan Paul

Degree: MS

Chair: Ronald P. Phelps

Resides: FAA Library

University: Auburn University

Location: Auburn, Alabama

Date: 2005

Pages: 101

Keywords: red snapper, amino acid supplementation, reproduction, eggs, larvae


Adult female red snapper, captured by hook and line, were injected with human chorionic gonado tropin hormone at 1100 IU/kg to induce spawning. Half of the fish were also immediately injected intramuscularly with a free amino acid (FAA) cocktail buffered in saline containing 250 mM valine (val), lysine (lys), leucine (leu), and isoleucine (ile) respectively at a rate of 20 mg FAA/kg of fish body weight,while the other half were administered a sham-saline injection. Fertilized eggs and larvae, maintained at 26.5C in seawater (30.9 ppt ),were analyzed by maternal origin over two days post-fertilization for morphological and FAA profile changes. A second set of red snapper maternal brood stock were treated identically to the conditions mentioned above to observe FAA concentrations in the plasma collected at various time points. In a second experiment, 36 to 48 hours post-hatch (hph) larvae were stocked into nursery tanks for a twenty-six day rearing trial to investigate if the FAA supplementation of maternal brood stock may have any long term effects on growth or survival for post yolk-sac larvae.
The FAA profile of newly fertilized eggs from the red snapper was described. Newly spawned fertilized eggs from control females had a mean total FAA content of 22.1 nmoles/egg, while fertilized eggs from FAA-injected females had a mean total FAA content of 28.3 nmoles/egg, representing a 28.1 % increase in total FAA content. The increase was not statistically significant. For the control and the FAA-injected fish, the val, lys, leu, and ile FAA content in eggs increased by 27.0 %, 28.7 %,28.3 %,and 28.7 % respectively with only ile and leu being statistically significant (P<0.05). At 24h post-hatch the mean total FAA content had decreased by 9.6 % and 84.8 % since fertilization for the control and FAA-injected fish. No significant differences between treatments were found for percent fertilization, percent hatch, or for percent survival of larvae right before first feeding. Patterns of FAA and oil globule utilization indicated that the oil globule may be spared during development due to FAA supplementation. Total body length and post-anal body depth for red snapper larvae at 12 hph were significantly greater in the larvae from the FAA supplemented broodstock (P<O.OO1 and P<O.O1 respectively). Plasma samples from the FAA-injected snapper showed a significant increase in Iys concentration at 30 h post-injection and a large decrease at 36 h post-injection compared to the controls. Poor survival of the post yolk-sac larvae occurred in both groups, with no survival by day 25. No treatment effect was observed for morphometric measurements taken up to day 14 for post yolk-sac larvae. The results implied that FAA supplementation of maternal brood stock can increase individual FAA in ovulated eggs, spare other energy reserves, and increase growth at certain time points. The FAA supplementation exhibited no benefit to the post yolk-sac larvae.

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