COLIN: SPAWNING AND LARVAL DEVELOPMENT OF HOGFISH 



erly winds drove oceanic water up onto the shelf 

 edge and also produced rough conditions. The 

 most turbid water was either associated with 

 calms, when the normal wind-driven flow from 

 offshore was eliminated, or when large amounts 

 of rain fell on Puerto Rico, particularly during 

 the summer-fall wet season. 



OBSERVATIONS 



Spawning Groups of L. maximus 



Males established a territory along the moat- 

 moat slope interface and defended it against the 

 intrusion of other males. The territory was un- 

 usual in being very elongate along the moat-moat 

 slope axis, but not ranging far either over the 

 sandy moat or up the moat slope. Males patrolled 

 their territory during the afternoon, passing 

 from one extreme of the sand-reef border to the 

 other without changing direction except as inter- 

 rupted by spawning rushes with females. Three 

 territories that I closely examined each encom- 

 passed about 100 m of the moat-moat slope inter- 

 face. The turning points at either end remained 

 consistent over the entire 20 mo. During active 

 spawning periods, generally 2-3 min, were re- 

 quired for one "pass" if no spawning occurred. 



An estimated 10-15 females occurred with 

 each male during the afternoon. Although I found 

 some evidence that females may remain with the 

 same male during any one day, I could not de- 

 termine if they changed males at other times. 



Time and Conditions of Spawning 



Active spawning was observed from Decem- 

 ber through April, but I could not be sure if 

 spawning also occurred in other months when 

 low water visibility often made observations dif- 

 ficult. Males, however, continued to patrol their 

 territories during the afternoon and were occa- 

 sionally seen to court females, but no spawning 

 was seen. In any event, it is certain from direct 

 observation that spawning during winter and 

 spring must be at least an order of magnitude 

 above any that may occur during summer and 

 fall. Davis (1976) reported that peak spawning, 

 based on gonad indices, of Florida Keys hogfish 

 is probably in February and March, although 

 some spawning may be occurring in other 

 months. Gonad indices were consistently low 

 from May through August. 



There is no evidence for lunar periodicity. Dur- 



ing peak spawning periods, spawning rushes 

 occurred on all phases of the moon and spawning 

 proceeded day after day with no apparent 

 change over the lunar cycle. 



Spawning began in midafternoon, but the 

 exact time of initiation was never observed. Hog- 

 fish were spawning by 1.5 h before sunset and 

 continued to spawn until 15-30 min before sun- 

 set. Males began to patrol more slowly as sunset 

 approached, and the frequency of spawning 

 rushes decreased quickly. Females seemed to 

 leave the spawning area, or at least were not 

 visible, by about 15 min before sunset. Males con- 

 tinued to patrol slowly until about sunset, then 

 left the immediate area of the sand-reef inter- 

 face. 



During the season of active spawning, current 

 speed or direction, surge on the bottom, and 

 water clarity seemed to have little effect on 

 spawning behavior. Rushes were observed under 

 nearly all conditions encountered. Water tem- 

 peratures ranged between 24° and 26°C. Day 

 length was short, being near the annual mini- 

 mum of about 11 h near the start of peak spawn- 

 ing in December and about 12.5 h by April. 



Spawning Behavior 



A female often indicated her readiness 

 to spawn by moving up in the water column on 

 approach of a male; otherwise, a male would 

 actively court females encountered on his patrol. 

 If a female was seen near the bottom, a male 

 would swim quickly towards her, shifting from 

 pectoral sculling to caudal fin swimming in a 

 burst of speed, and then dive towards her exhibit- 

 ing a courtship display. This consisted of erect- 

 ing the three long anterior spines of the dorsal fin 

 and shaking the posterior two of these rapidly 

 back and forth at about 8-10 cycles/s. The pos- 

 terior portion of the dorsal fin, the upper and 

 lower caudal fin margins, and the pelvin fins 

 were also agitated at a similar rate. Often the 

 male would swoop above the female and dive 

 rapidly towards her while displaying. If no re- 

 sponse was elicited, the male would move quickly 

 on to another female or resume patrolling. 



The spawning act was part of an elaborate 

 process termed the spawning rush, which could 

 be initiated by the male actively courting the 

 female or by the female simply rising up in the 

 water column as the male approached on his 

 patrol. The rush required 10-25 s total time from 

 the time the fish left the vicinity of the substrate. 



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