Evidence of intra- and inter-oceanic regional differences in the early life history of reef-associated fishes

Abstract

Data on a variety of early life history features among coral reef-associated fishes are reviewed and assessed for evidence of consistent regional intra-oceanic and inter-oceanic variation. The data currently available focus on interspecific, rather than intraspecific variation, and on demersal, rather than pelagic spawning families of fishes. Although data for comparisons are still sparse, the information available suggests that sizes of eggs produced, sizes of newly hatched larvae, durations of the planktonic larval stages and rates of larval growth, at least, can vary on spatial scales that range from across reefs to among oceans. Egg size, size of newly hatched larvae and planktonic duration appear to co-vary within families, which suggests they are not evolutionarily independent. No single factor is likely to underlie the range of regional variations apparent. We speculate on the causes of, in particular, inter-oceanic differences in life history features, review evidence for and agalnst these hypotheses, and suggest means whereby they can be tested.