Sarah
Drucker and Yelizaveta Kotlyarova

Abstract

An
experiment was performed on Discovery Bay coral reef, to determine
the aggressive tendencies of the damselfish Stegastes
adustus. A natural
setting behavior was observed and studied in four locations: within
the mangroves in an area with more algal cover and an area with less
algal cover, and within the jetty on the leeward and windward sides.
On an aggression scale from 1 to 5, S.
adustus exhibited on
average an aggression level of 4 marked by chasing. The damselfish
more notably chased away other damselfish that shared their area.
However, Haemulon
flavolineatum and
Scarus
taeniopterus were
also chased away in the jetty leeward location where they were found
sharing the habitats of the damselfish. In the mangrove area where
algae was more scarce and damselfish numbers were high S.
adustus were most
aggressive. S. adustus
were least aggressive in the jetty windward area with the least
population of damselfish and the lowest species variation, although
algae cover was low. It is suggested that S.
adustus are a strongly
aggressive fish and food supply and population count affect this
level of aggression.