It is of considerable interest that during the reproductive period of 

 Myrberg's study, the pattern of intracolony aggression in the laboratory and 

 possibly in the field differed from that recorded during the nonreproducti ve 

 period, with more aggression being directed towards the lowest ranking individuals 

 than towards those closest in rank. Field work similar to that of the present 

 study needs to be conducted during the reproductive period to establish if this 

 difference is significant and related to the phase of the reproductive cycle. 



In conclusion, the dominance relations in the bicolor damselfish during 

 the nonproductive period show both similarities and differences when laboratory 

 and field studies on colonies of similar size are compared. The nature of 

 these differences implies that the laboratory may be used for detailed work 

 impossible to carry out in the field, but that laboratory results must be 

 interpreted with caution and should not be used as the sole source of information 

 on the ecological significance of dominance relations. The importance of 

 parallel field and laboratory studies is emphasized, since it is evident that 

 many factors may influence intracolony aggression. 



ACKNOWLEDGMENTS 



I wish to thank Kimberly Lei ghton-Boulon for her invaluable help during 

 the field study and Ileana Clavijo, who did the organizational work prior to 

 the HYDROLAB mission. I also wish to thank the HYDROLAB staff in St. Croix for 

 making the mission so successful. For suggestions and comments on the manuscript, 

 I am very grateful to D. Y. Shapiro and G. R. Mitcheson. 



The study was carried out with the financial assistance of NOAA and of the 

 SERC of Great Britain Grant No. 78307917. 



LITERATURE CITED 



Beebe, W. 1947. "Notes on the Hercules Beetle, Dynastes hercules (Linn.) at 

 Rancho Grande, Venezuela, With Special Reference to Combat Behavior." 

 Zoologica, New York 32:109-116, . 



Chase, I. D. 1974. "Models of Hierarchy Formation in Animal Societies." 

 Behav. Sci . 19:374-382. 



Clarke, T. A. 1970. "Territorial Behavior and Population Dynamics of a 



Pomacentrid Fish, the Garibaldi Hypsypops rubicunda ." Ecol . Monogr. 40:189- 

 212. 



Coates, D. 1977. "The Social Behaviour of the Humbug Damselfish Dascyllus 

 aruanus (Pieces: Polacentridae) , With Notes on Two Other Species (D. 

 reticulatus and D. trimaculatus ) ." M. Sc. Thesis, Univ. Newcastle Upon 

 Tyne, England. 15*0 pp. 



Collias, N. E. 1944. "Aggressive Behavior Among Invertebrate Animals." 

 Physiol. Zool. 17:83-123. 



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