Author(s): Rachel Campbell , Ellen Town

Presentation: poster

Damselfish are known to be highly territorial when interacting with other reef fishes near their branching coral head territories. Researchers have suggested that this aggression is mainly due to food-resource competition. The goal of our study was to investigate the territorial behavior of the humbug damselfish (Dascyllus aruanus). We performed our study in the area southeast of Bylund Pass of Heron Island in Queensland, Australia. Observations of damselfish territories in Acropora coral heads were made on the reef flat in ten-minute periods over two consecutive days and included species identification of cohabitants and rejected species. The diet of the observed species was identified and used to analyze the pooled data. The study found that 70% of species that interacted with the humbug damselfish were accepted in cohabitation while 30% were rejected through territorial aggression. These percentages were consistent independent of the four observed diet categories: Zooplankton, Algae, Zoobenthos, and Other. Contrary to previous studies, the fish observed accepted a greater proportion of species into its territory than those rejected. While the causes for this lack of aggression remain unknown, other studies have found that ample space and food can cause damselfish to be less territorial than when resources are limited.

The College of Idaho     2112 Cleveland Blvd Caldwell, ID  8360     USA 208-459-5011    800-2C-IDAHO