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Fishery Bulletin 90(4). 1992 



M. mercenaria, and the portunid crab P. spinimanus 

 (Table 2). As above, no potential predators were ob- 

 served in the vicinity of the no-casita stations, and 

 mixed schools of snapper seldom strayed more than 

 15-20 m from casitas. However, several large snapper 

 of both species (L. griseus at the inner-bay site and 

 L. analis at the outer-bay site) were observed ~60 m 

 from the casitas. We also witnessed a stone crab feed- 

 ing on a lobster tethered beneath a casita, and on two 

 separate occasions observed octopus feeding on 

 tethered lobsters beneath a casita. 



During January 1989 at the inner-bay site, there was 

 a significant positive correlation between mean lobster 

 proportional mortality per day at a particular casita 

 station and the mean number of potential predators 

 occupying the same casita station (r 0.92, n 6, 

 P<0.01; Fig. 7). Conversely, there was no significant 

 correlation between lobster proportional mortality and 

 numbers of predators inhabiting casitas at the outer- 



bay site {r 0.11, n 6, NS), nor between proportional 

 mortality and the sizes of piscine predators (mm total 

 length; TL) at both sites (inner-bay: r 0.64, n 6, NS; 

 outer-bay: r 0.59, n 6, NS). 



Predator observations at the outer-bay site in August 

 demonstrated a more diverse predator guild than that 

 observed during January (compare Tables 2 and 3). 

 Although mutton snapper and yellowtail snapper were 

 abundant at large casitas, they were joined by larger 

 predators, including Nassau grouper Epinephelus 

 striatus and a great barracuda Sphyraena barracuda. 

 One barracuda was identified by particular scars near 

 the mouth and a broken tooth. This barracuda roamed 

 the entire experimental area. We also observed one 

 Nassau gi'ouper that moved between the 70 m no-casita 

 stations and the reef (see Fig. 4 for geography). 

 Another slightly smaller grouper moved back and forth 

 between the casitas, the 15 m no-casita stations, and 

 the reef. 



