group, then each recruit in the group should be of the same daily age. This 

 specific experiment has not yet been performed. 



As tantalizing as the possibility of kinship in recruits may be, a larger 

 related question prevails. What do larval fishes do when at sea? It is 

 axiomatic that they feed and grow, but beyond that the discussion group agreed 

 that the behaviors of larval reef fishes remain virtually unknown. Quantitative 

 data on the behaviors of a variety of species of reef fishes are crucial to 

 understanding the recruitment process. Answers will not be easy nor rapidly 

 forthcoming, for they must involve careful, stratified plankton sampling to 

 determine vertical distributions (at different times of the day), and also must 

 include specific experiments in the laboratory and on shipboard to assess the 

 responses of fish larvae to various stimuli. The investigations are greatly 

 complicated by larval growth. Because most reef fish larvae spend from 1 to 6 

 weeks and in some instances up to 15 weeks at sea (Brothers and Thresher, this 

 volume), behaviors must change as the larvae grow. It is critical, therefore, 

 to also evaluate the ontogeny of larval behaviors. The central importance of 

 such studies to the overall process of tropical fish recruitment, however, 

 should motivate investigators to overcome the difficulties that the study of 

 larval fish behavior presents. Especially in this area will creative and 

 imaginative investigations help, for they will provide short cuts to what 

 otherwise would be a prolonged undertaking. The lead provided by researchers 

 studying larval fish behaviors in temperate waters, fortunately, can be of 

 great assistance in getting started (e.g., Blaxter and Hunter, 1982; Lasker, 

 1981; on clupeoid fishes). 



Since the classic demonstrations of Johannes Schmidt (1922) that the 

 1 eptocephal us larvae of the European eel can drift at sea for not only months 

 but in some instances for more than a year, the duration of larval life of 

 fishes has provoked constant interest. Knowing how long a larva can exist at 

 sea has been particularly important in explaining long-distance transport of 

 reef fishes, e.g., the presence of Indo-Pacific reef species in the eastern 

 Pacific (Brothers and Thresher, this proceeding). The problem has been frustra- 

 ting because of the lack of methods to age larvae. The "invention" of the 

 daily otolith aging technique (Panella, 1971; Brothers, et al . , 1976) and the 

 "discovery" of a transitional check mark in the otolith increments that approxi- 

 mate settlement of the larvae from the plankton to the reef substrate (Brothers 

 and McFarland, 1981; Brothers, et al . , 1983; Victor, 1983) have revolutionized 

 the aging of larval fishes and, as a consequence, estimating the duration of 

 larval life of reef fishes. Brothers and Thresher's paper (this proceeding) 

 examines 115 species of Pacific reef fishes. Interestingly, over 80% of these 

 fishes have fairly short larval lives (< 45 days). All fishes with pelagic 

 larval durations in excess of 45 days are widely distributed (as expected). We 

 recognized that the use of otolith aging is an innovation that will assist in 

 providing answers to many questions concerning recruitment. Already we have a 

 better understanding of the lengths of larval life for a considerable number of 

 species. In some species the length of larval life can be restricted to only a 

 few days (e.g., French grunts, as noted by McFarland during the discussion) or 

 can encompass a highly variable number of days (from a short number to many 

 days and may show a strongly skewed distribution toward fewer days; Victor 

 noted during the discussion that this is the case for some wrasses). Given the 



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