COLIN: SPAWNING AND LARVAL DEVELOPMENT OF HOOFISH 



mucous bubbles around themselves that night 

 while floating free in the water near the surface. 

 None rested on the bottom. Such behavior is 

 known in other labrids but had been previously 

 unknown for L. maxim us or among free-floating 

 individuals. Adults have been observed many 

 times at night with no mucous bubble formation. 

 Bubble formation has not been previously noted 

 for "nonbenthic" labrids. The concept of bubble 

 formation as an antipredator device is supported 

 by its occurrence in postlarvae. Most larvae 

 broke free of the bubbles within seconds after 

 lights were turned on. 



At 17 d posthatch, postlarvae tended to stay 

 under material floating on the surface of the 

 water (mostly discarded clumps of mucous bub- 

 bles and Artemia cysts). Several would stay 

 under a single clump at the surface. No aggres- 

 sive interactions were noted. Larvae were white 

 and brown, the colors and pattern closely resem- 

 bling that of Sargassum, which may serve as 

 shelter for postlarvae carried into offshore 

 waters. 



Ten 18-d posthatch postlarvae were put into an 

 80 1 aquarium with a white sand substrate. Some 

 individuals rested on the bottom the first night, 

 while others remained in the water column, all in 

 mucous bubbles. By 34 d posthatch the fish ori- 

 ented strongly to the bottom. 



Little is known of the early life history of juve- 

 niles. Roessler (1964), who reported them from 

 Thalassia beds, found some correlation in abun- 

 dance with density of the bed. The larvae reared 

 in the present study were maintained until about 

 50 d posthatch, but after about 30 d began dying 

 without obvious cause. They were maintained 

 either in bare aquaria or with a white sand bot- 

 tom and were never exposed to a Thalassia com- 

 munity. They were fed a combination of Artemia 

 and wild zooplankton. In their natural environ- 

 ment there may be a diet shift to microinverte- 

 brates at an age when they began dying. 



Larvae did not undergo a quick metamorpho- 

 sis but gradually began to acquire brown and 

 white pigment of juveniles about 13 d posthatch. 

 While still free-swimming the larvae and post- 

 larvae became highly pigmented, which would 

 seem to be a distinct disadvantage in open water. 

 These pigmented young seemed to shelter be- 

 neath any floating objects in the rearing aquar- 

 ium, particularly the shards of their discarded 

 mucous bubbles, which were brown in color. 

 While there are no reports in the literature, their 

 coloration would serve to conceal them in float- 



ing Sargassum and potentially other floating 

 marine plants. Quick development and the lack 

 of a distinct metamorphosis implies that perhaps 

 the optimum survival strategy to the juvenile 

 stage would be an inshore transport of eggs and 

 larvae and retention of juveniles near the spawn- 

 ing location. Unless associated with floating 

 objects or plants, large L. maximus larvae would 

 be at a distinct disadvantage in the pelagic 

 realm. The life history of L. maximus implies 

 that the postlarvae become benthic in an inshore 

 location near sea grass beds and subsequently 

 move to offshore reefs (Davis 1976). From the 

 present study there seems no control of spawning 

 condition which would produce an inshore dis- 

 persal of eggs (currents, winds, tides, or wave 

 action) and except for seasonal differences, it 

 seems eggs are simply broadcast randomly with- 

 out the influence of environmental conditions 

 which would influence their ultimate destina- 

 tion. 



ACKNOWLEDGMENTS 



Major equipment was provided by two grants 

 (OCE 76-02352 and OCE78- 25770) from the Divi- 

 sion of Ocean Sciences, National Science Foun- 

 dation, to the author. Much of the operational 

 support was provided by two grants from the Na- 

 tional Geographic Society. Ileana Clavijo and 

 Charles Arneson participated in most of the field 

 work. Charles Arneson provided Figure 2. Two 

 journal reviewers provided valuable criticism of 

 the manuscript. 



LITERATURE CITED 



Adey, W. H., I. G. MacIntyre, and R. Stuckenrath. 



1977. Relict barrier reef system off St. Croix: Its implica- 

 tions with respect to late Cenozoic coral reef develop- 

 ment in the western Atlantic. Proc. Third Int. Coral 

 Reef Symp., Miami. 2:15-22. 



Davis, C. 



1976. Biology of the hogfish in the Florida Keys. M.S. 

 Thesis, Univ. Miami, Coral Gables, 86 p. 



Glynn, P. W. 



1973. Ecology of a Caribbean coral reef. The Pontes reef- 

 flat biotope: Part I. Meteorology and hydrography. 

 Mar. Biol. (Berl.) 20:297-318. 



Houde, E. D., AND K. Tanaguchi. 



1977. Methods used for rearing marine fish larvae at the 

 Rosenstiel School of Marine and Atmospheric Sciences. 

 Report to Environmental Protection Agency. 



Johannes, R. E. 



1978. Reproductive strategies of coastal marine fishes in 

 the tropics. Environ. Biol. Fishes 3:65-84. 



MacIntyre, I. G. 



1972. Submerged reefs of eastern Caribbean. Bull. 



861 



