FISHERY BULLETIN: VOL. 80, NO. 4 



would follow pairs of L. maximus so closely that 

 the spawning rush would be interrupted, causing 

 both the male and female to return to the sub- 

 strate. 



Yellowtail snappers were much more abun- 

 dant at the actual insular shelf edge than at the 

 hogfish spawning area. At the shelf edge they 

 formed loose aggregations of from several hun- 

 dred to several thousand individuals feeding on 

 zooplankton high above and beyond the shelf 

 edge. Only a relatively few were found near the 

 moat-moat slope interface, some 100 m away, but 

 these few influenced the reproductive success of 

 L. maximus. 



Gonad indices of both sexes vary considerably 

 during the year (Davis 1976) in a pattern consis- 

 tent with my observations. Gonad indices of 

 males for each month ranged from about 0.14 to 

 0.20 (gonad weight as a percentage of body 

 weight) for December to April and from 0.0 to 

 slightly less than 0.10 for June to August. The in- 

 dices were relatively low compared with those for 

 other Caribbean labrids (Warner and Robertson 

 1978) but on a level with those of terminal males 

 (both primary and secondary) of some other spe- 

 cies. Lachnolaimus maximus is monandric (no 

 primary males) (Davis 1976) and haremic, and 

 the low gonad indices of males are consistent 

 with the data for larger Caribbean labrids of 

 Warner and Robertson (1978). Males are close to 

 an order of magnitude heavier than other "large" 

 Caribbean labrid males (Halichoeres radiatus 

 and Bodianus rufus) and two orders of magni- 

 tude above those of smaller species. Although the 

 gonad indices are low compared with those of 

 other species, the actual gonad is large. The rela- 

 tive size between large and small labrids may not 

 be very important. Males observed in the present 

 study spawned repeatedly each afternoon during 

 the active season. While data for an entire after- 

 noon were not available, I estimated that at least 

 some males engaged in 50-100 spawning rushes/ 

 afternoon and that they were capable of fertiliz- 

 ing each group of eggs released. 



The female-male ratio among adults also 

 seems higher than in most other Caribbean lab- 

 rids. Davis (1976) reported a ratio of 13:1 in the 

 724 individuals he sampled, which is close to the 

 estimated 10:1 ratio that I observed. Warner and 

 Robertson (1978), however, reported a ratio of 

 only 3:1 or less for most species. 



The spawning location, about 100 m from the 

 insular shelf edge rather than at the edge itself, 

 appears contrary to some of the concepts put for- 



ward by Johannes (1978). It is true that many 

 reef fishes producing planktonic eggs often move 

 considerable distances to be able to release eggs 

 at insular shelf edges where they may be trans- 

 ported offshore. Hogfish, however, rarely move 

 long distances to spawn. Adults can easily range 

 to the shelf edge for spawning and some individ- 

 uals probably remain along the shelf edge at 

 night after spawning ceases. The potentially 

 heavier egg predation by yellowtail snapper at 

 the shelf edge may help restrict hogfish spawn- 

 ing to more inshore areas. In addition, hogfish 

 are typically found on the sandy margins of reefs 

 where they feed largely on sand-dwelling mol- 

 luscs (Randall and Warmke 1967) and the moat- 

 moat slope interface area provides both reef shel- 

 ter and open sand. Territories held by males may 

 also represent feeding areas, whereas the actual 

 shelf edge near the spawning area has little sand, 

 and consists mostly of rock and coral. 



EGG AND LARVAL DEVELOPMENT 



Eggs are 1.2 mm in diameter and have a single 

 oil globule 0.17 mm in diameter. They float and 

 lack any visible pigment. They hatched 23 h after 

 fertilization at 25.5°C. 



Larvae were reared at about 26°C but the tem- 

 perature could not be closely controlled. When 

 hatched, the larvae had little pigment. Scattered 

 melanophores occurred in the head region and in 

 a line on the dorsal margin of the body (Fig. 3a). 

 They did not orient until about 24 h after hatch, 

 but the eyes were still unpigmented at that stage 

 (Fig. 3b). A line of melanophores along the ven- 

 tral surface of the body began to develop at this 

 time. Sometime between 24 and 36 h posthatch 

 the eyes became pigmented. First food was 

 added 31 h after hatch. Larvae seemed to be 

 making feeding strikes by about 42 h posthatch 

 (Fig. 3c). At this stage the amount of pigment 

 along the ventral surface of the body increased 

 and was plainly visible to the unaided eye. The 

 black pigment increased daily until 7-8 d post- 

 hatch and then remained stable. At 7 d posthatch 

 feeding with Artemia salina was initiated. At 

 this time pigment cells were visible on the tip of 

 the lower jaw and on the lower margin of the gill 

 cover. By 10 d posthatch the fin rays had begun to 

 develop, the pelvic fin buds were apparent, and 

 notochord flexion had occurred. 



Gas bladder inflation occurred 10 d posthatch 

 (Fig. 3e) in 10-20% of the larvae. Larvae without 

 the bladder inflated would swim with the tail 



858 



