of otolith "settlement marks" in juveniles and adults, the latter involving 

 techniques similar to those used in other studies (Brothers and McFarland, 

 1981; Victor, 1982; Thresher and Brothers, in press). Total duration of the 

 pelagic stages was assumed to be equal to calculated otolith ages for most 

 demersal spawning fishes. This assumption is based on limited data (Brothers, 

 unpublished data) which suggests that daily growth increments in most demersal 

 spawning fishes begin forming shortly after hatching. The only demersal spawning 

 families for which this is not likely to be true are Balistidae and Siganidae, 

 both of which hatch as relatively undeveloped prolarvae (see review in Thresher, 

 1984). For these two families, 2 days were added to calculated pelagic durations 

 to account for the likely duration of pelagic pre-feeding stages. For pelagic 

 spawning fishes, total duration of the pelagic stages was estimated by adding 3 

 days to otolith ages. This was based on a mean incubation time of 43.1 hours 

 for pelagic eggs of such fishes (Thresher, 1984), plus limited data suggesting 

 that another 24 hours may pass before the first growth increment forms (Brothers, 

 unpublished data). 



Species distributions were based on taxonomic reviews and comparison of 

 faunal lists for different areas. The extent of distribution was quantified by 

 dividing the tropical Indo-Pacific into 29 "bio-geographical areas" and counting 

 the number of areas inhabited by each species. Division of the Indo-Pacific 

 follows Allen (1979). The rationale behind this approach is discussed in 

 Thresher and Brothers (in press). 



Data were obtained for 115 species (see table 1) in 22 families, essentially 

 all those we had available to us. The taxonomic distribution is not intended 

 to be qualitatively or quantitatively representative of typical reef 

 ichthyofaunas, although effort was made to include representatives of as many 

 families as possible. The only fishes specifically excluded from the analysis 

 were Hawaiian endemics and a few families, such as kyphosids and carangids, 

 that are known or strongly suspected to raft as juveniles or adults under 

 floating objects. The few Hawaiian endemics we had available were excluded 

 because of difficulty in discerning a single or discrete "settlement mark" (see 

 Thresher and Brothers, in press, for further discussion of this problem). Some^ 

 material was obtained for us directly in the field (the Philippines, Japan, the 

 Marshall Islands, and Australia), but the majority were obtained as juveniles 

 and small adults from the aquarium. As such, most were probably collected in 

 the Philippines, the Hawaiian Islands, or off the Australian Great Barrier 

 Reef. Specimens maintained in captivity for a variable period were suitable 

 for our study since they were initially captured as settled juveniles or adults 

 (rather than being reared in captivity) and because there are no indications, 

 nor expectations, that conditions in captivity affect structures already laid 

 down in the otoliths. 



Specific samples sizes were typically small (range 1 - 15, "X = 2.62, mode 

 = 1), but intraspeci f ic variation in most species examined was also small (see 

 results; also Thresher and Brothers, in press). Calculated durations, therefore, 

 are likely to be robust for most species examined. Results of our analysis are 

 also sufficiently broadly based that minor adjustments of a few species are likely 

 to have little or no impact on the conclusions drawn. 



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