Are different feeding strategies utilized by the bar jack (Caranx ruber) related to foraging success in coral reef habitats?

Foraging success is affected by choice of feeding association, color phase, and habitat type. Bar jacks (Caranx ruber) exhibit a number of feeding associations, changes in coloration from silver to dark brown/black, and utilize different habitat types within the fringing reef ecosystem for feeding. The objective of this study is to determine if foraging success is affected by 1) feeding association utilized (individual, conspecific, or multispecies groups) 2) color (black or silver) or 3) habitat type (reef flat or reef slope). Observations of C. ruber were conducted at two dive sites on the fringing reef of Bonaire using SCUBA. The number of bites min-1 was used as a measure of foraging success. Analysis of results shows that C. ruber has significantly greater foraging success when feeding alone and in multispecies groups as opposed to feeding with conspecifics. Dark brown/black C. ruber have double the feeding rate as that of silver and habitat type did not have an affect on C. ruber foraging success. In conclusion, foraging success of C. ruber, measured in bites min-1 , is affected by choice of feeding association and coloration, but is not affected by choice of habitat.

This student research was retrieved from Physis: Journal of Marine Science V (Spring 2009)19: 10-13 from CIEE Bonaire.

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