NOTE Mueller: Size structure of Lutjanus analis 



575 



near inlets and patch reefs (Dennis 1 ). Size-specific 

 asymmetries in both social and foraging behaviors 

 suggest that these groups form dominance hierar- 

 chies (Mueller, 1994; Mueller et al., 1994). Assum- 

 ing that large L. analis did not migrate from the study 

 site (Beaumariage, 1969; author's personal observ. ) 

 and given that higher proportions of aggressive en- 

 counters occur among medium-size and large fish 

 compared with small fish (Mueller et al., 1994), it is 

 possible that the few large, dominant L. analis lim- 

 ited the number of medium-size fish on site through 

 social interactions (sensu Doherty 1983; Jones, 1987; 

 Forrester, 1990). However, because empirical evi- 

 dence is not available to support this conclusion, ex- 

 periments should be designed to test whether large 

 L. analis are a limiting factor. 



Changes in the size structure of L. analis between 

 1991 and 1992 (i.e. the shift from small towards 

 medium-size fish; Table 1) may also be related to 

 growth. For example, small L. analis (1+ yr) feed 

 proportionally more often than medium-size or large 

 fish during daylight hours (0600-1730) and are in- 

 volved in very few intraspecific encounters (Mueller 

 et al., 1994). By limiting their interactions with con- 

 specifics, small fish ostensibly have more time and 

 energy available for growth (>0.8 cm/mo during years 

 1 and 2; Claro, 1981; Mason and Manooch, 1985). Fur- 

 ther studies may be designed to test this hypothesis. 



In conclusion, managers of reef fisheries are chal- 

 lenged with determining whether shifts in the size 

 structure of populations are due to normal recruit- 

 ment and postrecruitment events or to fishing pres- 

 sure. For example, low abundance of a certain size 

 class may be due to intraspecific competition 

 (Doherty, 1983; Jones, 1987; Forrester, 1990) or 

 growth rather than to the effects of fishing. How- 

 ever, previous studies also indicate lower average size 

 and abundance offish captured on exploited reefs as 

 opposed to unexploited reefs (see review by Russ, 

 1991). I have provided evidence of seasonal varia- 

 tion in the size structure of L. analis associated with 

 unfished reefs. Although potential biases exist, this 

 information should be useful for making relative com- 

 parisons with analogous populations subjected to 

 fishing pressure. 



Acknowledgments 



I would like to thank G. D. Dennis and R. I. Wicklund 

 for helpful advice and encouragement. This research 

 was supported by a grant from the National Under- 



1 Dennis, G. Caribbean Marine Research Center, 805 E. 46th 

 Place, Vero Beach, FL 32963. Unpubl. data, 1992. 



sea Research Program, National Oceanic and Atmo- 

 spheric Administration, U.S. Department of Com- 

 merce and by the Caribbean Marine Research Center. 



Literature cited 



Beaumariage, D. S. 



1969. Returns from the 1965 Schlitz tagging program in- 

 cluding a cumulative analysis of previous results. Fla. 

 Dep. Nat. Resour., Mar. Res. Lab., Tech. Ser. 59, 38 p. 



Bortone, S. A., and J. L. Williams. 



1986. Species profiles: life histories and environmental re- 

 quirements of coastal fishes and invertebrates (South 

 Florida) — gray, lane, mutton and yellowtail snappers. 

 U.S. Fish Wildl. Serv., Biol. Rep. 82, 18 p. 



Brownell, W. N., and W. E. Rainey. 



1971. Research and development of deepwater commercial 

 and sport fisheries around the Virgin Islands Plateau. 

 Caribb. Res. Inst. Contrib. 3, 88 p. 

 Claro, R. 



1981. Ecologia y ciclo de vida del pargo criollo, Lutjanus 

 analis (Cuvierl, en la plataforma Cubana. Inf. Cient.-Tec. 

 Inst. Oceanol. Acad. Cienc. (Cuba) 186, 83 p. 

 1983. Dinamica estacional de algunas indicadores 

 morfofisiolbgicas del pargo criollo, Lutjanus analis (Cuvier), 

 en la plataforma Cubana. Rep. Invest. Inst. Oceanol. 

 Acad. Cienc. Cuba 22:1-14. 

 Craik, W. J. S. 



1981. Underwater survey of coral trout Plectropomus 

 leopardus (Serranidae) populations in the Caprieornia sec- 

 tion of the Great Barrier Reef Marine Park. Proc. 4th Int. 

 Coral Reef Symp. 1:53-58. 

 Doherty, P. J. 



1983. Tropical territorial damselfishes: Is density limited 

 by aggression or recruitment? Ecology 64:176-190. 

 Erhardt, H. 



1978. Elektronenmikroskopische untersuchungen an den 

 eihullen vonLutjanus analis (Cuvier and Valenciennes, 1828) 

 (Lutjanidae, Perciformis, Pisces). Biol. Zbl. 97:181-187. 

 Erhardt, H., and W. Meinel. 



1977. Beitrage zur Biologie von Lutjanus analis (Cuvier and 

 Valenciennes 1828 )( Lutjanidae, Perciformis, Pisces) an der 

 kolumbianischen Atlantikkuste. Int. Revue Gesamt. 

 Hydrobiol. 62:161-171. 

 Forrester, G. E. 



1990. Factors influencing the juvenile demography of a 

 coral reef fish. Ecology 71:1666-1681. 

 Garcia-Arteaga, J. P., R. Claro, L. M. Sierra, and 

 E. Valdes-Munoz. 



1990. Caracteristicas del reclutamiento a la plataforma de 

 los juveniles de peces neriticos en la region oriental del 

 Golfo de Batabano. In R. Claro ( ed. ), Asociaciones de peces 

 en el Golfo de Batabano, p. 96-121. Editorial Academia, 

 Habana, Cuba. 

 Gulf of Mexico Fishery Management Council. 



1992. Help proposed for mutton snapper. Gulf Fish. News 

 12(4):2. 

 Jones, G. P. 



1987. Competitive interactions among adults and juveniles 

 in a coral reef fish. Ecology 68:1534-1547. 



1990. The importance of recruitment to the dynamics of a 

 coral reef fish population. Ecology 71:1691-1698. 



1991. Postrecruitment processes in the ecology of coral reef 

 fish populations: a multifactorial perspective. In P. F. Sale 



