University of Puget Sound
The prevalence of coral disease appears to be increasing worldwide, although little is known about how these diseases are transmitted between coral colonies. To examine whether corallivorous fishes could potentially act as disease vectors, this study examined whether and which fish species feed on diseased coral, and whether these fishes actively target diseased coral sections. Branches of Acropora muricata with brown band disease were filmed in the field, and bites taken by fishes on different sections of the coral (live tissue, tissue margin, disease band, dead skeleton, and algae) were recorded. For each fish species, electivity indices were calculated for each coral section to determine feeding preferences. Additionally, feeding preferences for diseased or healthy coral fragments were determined for the corallivorous butterflyfish Chaetodon lunulatus and wrasse Labrichthys unilineatus in aquaria. Many fishes, including non-corallivores, consumed diseased coral and exhibited a preference for the disease band and adjacent live tissue margin. Butterflyfishes, including C. lunulatus, and particularly Chaetodon aureofasciatus, showed a strong preference for the tissue margin, while L. unilineatus showed a clear preference for the disease band. The obligate corallivores (Chaetodon spp. and L. unilineatus) are most likely to act as disease vectors, as they were the only fishes to feed substantially on live tissue in addition to the disease band, and they are known to repeatedly feed on multiple coral colonies in their territories. The non-corallivores are unlikely to be spreading disease, and may actually slow the disease progression by selectively consuming brown band ciliates.
Aquaculture and Fisheries | Biology | Environmental Health and Protection
Rogers, Tanya, "Corallivorous Reef Fishes as Potential Vectors of Coral Disease Based on a Study of Dietary Preferences" (2008). Independent Study Project (ISP) Collection. Paper 560.