Causes of Growth Depensation in Red Drum, Sciaenops Ocellatus, Larvae |
| |
Authors: | Michael E Smith Lee A Fuiman |
| |
Institution: | (1) Marine Science Institute, University of Texas at Austin, 750 Channel View Drive, Port Aransas, TX, 78373, U.S.A.;(2) Present address: Department of Biology, University of Maryland, College Park, MD, 20708, U.S.A. |
| |
Abstract: | Individual growth rates, and thus sizes at a given age, vary within cohorts of fishes reared in the laboratory, field enclosures, and the wild, but the causes of this variability are poorly understood. We examined effects of three variables (food availability, a diet shift, and fish density) on growth depensation in red drum, Sciaenops ocellatus, larvae in laboratory experiments. Absolute variance in length of larvae was greater with higher food availability, and relative variance (CV) for a cohort at 14 d posthatching was positively correlated with its CV at 7 d posthatching, over which time CV doubled. Supplementation of a rotifer diet with Artemia nauplii (diet shift) increased growth rate and length variance, but not CV. Individually-reared and group-reared larvae had similar growth rates, but group-reared larvae exhibited higher CVs than individually-reared larvae. The observation that food availability and diet shifts affected absolute size variance, while fish density affected relative size variance of red drum larvae, indicates that both absolute and relative size variance are important to understand how environmental factors affect growth depensation. |
| |
Keywords: | growth rate variance food availability size hierarchy density diet shift |
本文献已被 SpringerLink 等数据库收录! |
|