1974; Sale and Dybdahl , 1975, 1978; Sale, 1977, 1978a_). Thus, species composition 

 on a reef should change through time, but over years as opposed to centuries 

 or longer. A contrasting hypothesis suggests that species composition is more 

 deterministic and dependent on competition between adults for resources (Smith, 

 1973, 1978; Smith and Tyler, 1973). Recruitment from the plankton, therefore, 

 would not primarily affect diversity but the abundance of each species over 

 time. No doubt there is truth in each view, but the controversy continues with 

 additional participants (Gladfelter and Gladfelter, 1978; Holies, 1978; Talbot, 

 et a"l. s 1978; Gladfelter, et cTL , 1980; Ogden and Ebersole, 1981; Shulman, 

 1983; Abrams, 1984). 



Given the virtually universal use of a pelagic egg and/or larval phase and 

 its potential significance to explanations of the high diversity amongst 

 assemblages of coral reef fishes, investigations of the reproductive activities 

 of adults, the disposition of their eggs and larvae at sea, and the effect(s) 

 of currents on the dispersal of these propagules are, therefore, not inconsequen- 

 tial. If, for example, the recruitment of each species is not consistent over 

 a reasonable time scale, then the high diversity of coral reef fishes could not 

 be maintained. 



In general, data about recruitment processes in coral reef fishes are 

 sparse and must often be gleaned from literature that primarily deals with 

 other aspects of coral reef fish biology. Over the last few years, however, 

 efforts have been directed toward recruitment in particular species. Given the 

 central importance of recruitment to coral reef fish community structure, we 

 expect that larval biology at sea will be explored in great detail over the 

 coming decade. Here we summarize what is presently known about recruitment and 

 closely related processes in coral reef fishes. 



REPRODUCTION 



Spawning activities in coral reef fishes vary considerably. Only over the 

 last 10 years have sufficient direct observations accumulated to provide a 

 basis for understanding how the spawning act might be adaptive. Many reef 

 species spawn over long periods of each year, but they usually show maximum 

 reproduction in either spring and/or fall (Munro, et a! . , 1973). In Munro's 

 study, which examined the state of the gonad as an index of reproductive 

 potential, over half of the species were active for longer than 6 months. 

 Labrids (Warner, et ajk , 1975) and some haemulids (McFarland, 1980, 1982) spawn 

 over the entire year, but many species have highly restricted spawning seasons. 

 Between these extremes, however, some species produce all of their eggs in a 

 single or in very few reproductive acts, while others rely on a more consistent 

 release which involves the release of fewer eggs during each reproductive 

 bout. It is difficult to generalize with certainty how these highly varied 

 spawning tactics relate to dispersal and recruitment. This is further complicated 

 by the fact that virtually every assemblage of coral reef fishes contains 

 species that utilize each reproductive tactic. 



Many species tend to show periodicity of spawning over a season or even 

 longer. In a survey of reproduction in 52 tropical fishes, Johannes (1978) 



38 



