| INFLUENCE OF MATERNALLY DERIVED FATTY ACIDS ON ECOLOGICAL PERFORMANCE OF WILD AND HATCHERY LARVAL RED DRUM (SCIAENOPS OCELLATUS) |
| FUIMAN, Lee A., University of Texas Marine Science Institute, Port Aransas, Texas 78373, lee.fuiman@mail.utexas.edu; Perez, K.P., University of Texas Marine Science Institute, Port Aransas, Texas 78373.
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| Dietary intake of certain essential fatty acids, particularly arachidonic acid (ARA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA,) by fish larvae is known to benefit their growth and survival, and correlations have been reported recently between concentrations of ARA and DHA in eggs and the anti-predator behavior of larvae three weeks after hatching. We evaluated how anti-predator behavior in red drum larvae produced in hatcheries differs from that of individuals reared from eggs collected from the wild and whether differences in behavior are related to maternally derived fatty acids. We analyzed both the fatty acid profile of eggs and escape swimming performance of larvae reared from 48 spawns collected from hatchery broodstock and 2 collections of wild eggs from Port Aransas, Texas. Fatty acid profiles of hatchery eggs differed from wild collected eggs: 12 of 27 (44%) fatty acids analyzed were more concentrated in hatchery produced eggs than in wild eggs. The reverse pattern was true for 15 of 27 (55%) fatty acids. Of the fatty acids that are commonly associated with increased growth and survival in larval fishes, concentrations of both EPA and DHA were higher on average in hatchery eggs than wild eggs (31% and 42% higher, respectively), whereas mean ARA concentration in wild eggs was higher than in hatchery eggs (28% higher). No significant differences in mean escape performance variables existed between the hatchery-produced larvae and larvae from wild eggs (P > 0.1). However, variability in mean reactive distance, response latency, response speed, and response duration decreased when concentrations of particular fatty acids in eggs exceeded certain levels. For some of these variables (i.e., latency, response speed), performance of larvae reared from wild-collected eggs was in the region of low variability. Understanding which combination and levels of fatty acids are required for generating consistent escape behavior will improve our efforts to produce larvae of a consistent and high quality, and it will enhance our understanding of mechanisms behind fish survivorship and recruitment in the wild. |
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