Development of swimming abilities in reef fish larvae

Recent studies have revealed that reef fish larvae have excellent sustained swimming capabilities and considerable potential for modifying their dispe rsal patterns by active swimming. However, these studies concentrate solely on the late pelagic phase. We examined the development of swimming abiliti es from hatching through to settlement in 3 reef fish species (Pomacentrus amboinensis, Sphaeramia nematoptera, Amphiprion melanopus). Larval rearing provided larvae at all stages of development. Experiments were conducted in flow chambers designed for measuring the critical and sustained swimming c apability of young larvae. In all 3 species, critical swimming ability incr eased steadily with age, size, relative propulsive area and developmental s tage of the larvae. In contrast, sustained swimming ability showed a marked inflection during development. Differences among species throughout develo pment appear to reflect variations in the developmental patterns of the 3 s pecies. Propulsive area was highly correlated with swimming ability and may prove useful for estimating swimming capabilities among species. The resul ts suggest that some species have the potential to actively modify their di spersal patterns from an early age.