Oxygen consumption of newly settled summer flounder, Paralichthys dentatus (Linnaeus, 1766)

The timing of larval metamorphosis in summer flounder, Paralichthys dentatus, from the same cohort (i.e., siblings with the same parents) and among cohorts (different parents) is variable due to large differences in individual growth rates. In an effort to understand the energetic basis for growth rate differences, rates of routine (RR) and specific dynamic action (RSDA) respiration (μg O2/fish/h) were measured in groups of newly metamorphosed summer flounder and compared among fish of different sizes (15, 20, 25 and 30 mm total length, TL) and between fast- and slow-growing fish from five cohorts each having a different set of parents. Although rates of RR significantly increased with increasing fish size (RR = 3.02 ± 1.04 DM0.88 ± 0.12, they were not significantly different between the fastest and slowest growing fish within a cohort. Respiration rates rapidly increased during feeding and the mean ± SD peak RSDA was 1.91 ± 1.29 · RR. The mean ± SD energy loss due to RSDA was 15.6 ± 11.5% of the ingested prey energy. Differences in RSDA were noted among fish of different sizes and between fast- and slow-growing fish. However, the results of this study suggest that the energetic basis for growth differences among summer flounder appears to result from processes related to energy intake (e.g., food consumption) rather than those related to routine or feeding energy loss. © 2006 Elsevier B.V. All rights reserved.