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. INTRODUCTIONResearch on coral-reef fishes centers on 2 areas: the tropical western Atlantic and the tropical western and central Pacific. The results of studies in one area are frequently compared directly with those in the other (e.g. Bohnsack & Talbot 1980, Gladfelter et al. 1980, Talbot & Gilbert 1981, and integrated to generate a broader understanding of the factors that determine the structure and diversity of reef fish communities (e.g. Ehrlich 1975, Smith 1978, Sale 1980). An assumption implicit in the integration of such studies, or indeed of studies from different regions within the same ocean, is that the biology of confamilial fishes in different areas is fundamentally the same. This assumption seems reasonable, given the broad taxonomic overlap of the reef-associated fish fauna around the world. Few families are restricted to only one region, and in most cases overlap is extensive at the However, few direct, quantitative comparisons have been made of the behavior, ecology or physiology of related fishes inhabiting coral reefs in different parts of the world (see reviews in Sale 1980, Pamsh 1989, Thresher in press). Even less work has focussed on the possibil.ity of regional differences in life histories. Several studies have suggested that spawning periodicity varies between sites in a number of families (see Johannes 1978). Randall (1961) reported that the size at settlement for acronurus Acanthurus tnostegus varies between sites within the tropical Pacific, apparently as a function of water temperature (higher temperatures = smaller fish at settlement). Victor (1986) noted that the duration of the planktonic larval stages of Hawaiian 188 Mar Ecol. Prog. Ser. 57: [187][188][189][190][191][192][193][194][195][196][197][198][199][200][201][202][203][204][205] 1989 endemic labrids appeared to be longer than those of related species at Guam. Subsequently, Thresher et al. (1989) reported that planktonic durations of pomacentrids found on the...

Comparisons of sponge populations across the Barrier Reefs of Australia and Belize: evidence for higher productivity in the Caribbean

“…While this evidence is correlative, it supports other observations (Birkeland 1988, Thresher & Brothers 1989, Vermeij 1989 suggesting that these differences are real and significant.…”

Tropical Transpacific Shore Fishes

“…In the TEP,~94% of the shore fishes have pelagic larvae and 61 % of such species produce them from pelagic eggs . Indo-Pacific reef fishes that produce pelagic larvae from demersal eggs tend to have smaller geographic ranges than do pelagic spawners (Thresher and Brothers 1985, Thresher 1991, Pyle 1999, Hughes et al 2002, Jones et al 2002. Demersal spawners may have a reduced dispersal ability due to their larvae (1) tending to remain inshore (while those of pelagic spawners often develop offshore) (Leis 1986, Brogan 1994, and (2) having short pelagic larval durations (Thresher and Brothers 1985, Thresher 1991.…”

“…Indo-Pacific reef fishes that produce pelagic larvae from demersal eggs tend to have smaller geographic ranges than do pelagic spawners (Thresher and Brothers 1985, Thresher 1991, Pyle 1999, Hughes et al 2002, Jones et al 2002. Demersal spawners may have a reduced dispersal ability due to their larvae (1) tending to remain inshore (while those of pelagic spawners often develop offshore) (Leis 1986, Brogan 1994, and (2) having short pelagic larval durations (Thresher and Brothers 1985, Thresher 1991. Although most analyses of zoogeographic patterns of tropical fishes in relation to dispersal modes have focused on contrasts between demersal-and pelagic-spawning teleosts that produce pelagic larvae, Pyle (1999) included species that lack any pelagic life-history phase in his analysis of the distributions of shore fishes in Oceania.…”

Variable larval growth in a coral reef fish

“…Secor & Dean 1989, Hare & Cowen 1995. The use of otolith records in field studies has enabled the description of seasonal (Bell et al 1995, Fowler & Short 1996, annual (Sponaugle & Cowen 1994, Meekan & Fortier 1996 and geographic differences in early life-history traits such as growth rates and larval duration (Thresher & Brothers 1989, Wellington & Victor 1992). These differences may be the result of maternal influence (egg quality : Chambers 1997) and genotype (Chambers & Leggett 1992), as well as environmental factors such as food availability (Mosegaard et al 1988, McCormick & Molony 1992) and temperature (Hovenkamp 1990, Fitzhugh et al 1997).…”