Epizootics and Disease of Coral Reef Fish in the Tropical Western Atlantic and Gulf of Mexico

A review of the published literature on coral fish epizootics and disease suggest that a variety of bacterial, viral, and fungal pathogens and several host-ectoparasite relationships can affect coral reef fishes and populations. Biotoxic organisms (e.g., Caulerpa), toxic dinoflagellates (e.g., Gambierdiscus and Prorocentrum), and bacterial infection by Streptococcus iniae have been most commonly cited as the etiologic agents associated with coral reef fish epizootics in the Tropical Western Atlantic and Gulf of Mexico. Reports of tumors and related lesions in coral reef fishes are relatively uncommon. A chronic iridoviral disease known as lymphocystis affects angelfish, wrasses, grunts, and many other species that inhabit coral reefs and certain rhabdoviruses are also known to cause mortality in angelfish. Other coral reef fishes, such as snappers and damselfishes seem most susceptible to neurofibrosarcomas and neurofibromas.

A variety of protozoan and metazoan ectoparasites are commonly found on coral reef fishes. In most cases, these parasites are found in low numbers and under normal conditions cause few or minor pathogenic effects. However, recent research suggests a need to reconsider the role of parasitism in the mortality of coral reef fishes. There is growing evidence that the ecological relationships between reef fishes, ectoparasites, and cleaner fishes are important to overall functioning, survival, and the social structures of fishes on coral reefs. However, until such a time as the spatial variations in abundance and species distribution, rarity, temporal variations in reef fish populations, and mechanisms of disease transmission are understood, it will be difficult to assess the potential effects of disease on reef fish populations.

Keywords:

• reef fish
• fish health
• epizootics
• disease
• pathogens
• parasites
• cleaner fishes

Acknowledgments

This project was performed in part by using the services provided by the National Cancer Institute's Registry of Tumors in Lower Animals, operated by Experimental Pathology Labortatories, Inc., NO2-CB-27034. Special thanks to Dr. Maryln Wolfe and Dr. Jeffrey C. Wolf for their verifications of diagnoses associated with tumors records in the Registry.