We are encouraging Tropical Western Atlantic REEF surveyors to be on the lookout for a skin condition that is affecting reef fish in the Caribbean. Black Spot Syndrome (BSS) affects many reef fish but can easily be observed on Ocean Surgeonfish, especially when they are pale in color. The black spots are usually on the fins and skin of the affected fish. In many cases, Black Spot Syndrome is caused by a trematode parasite, Scaphanocephalus spp., which moves from marine snails to reef fish and ultimately into osprey, which consume the infected fish. Infections seem to be especially common in Bonaire and Curacao, although other areas with reported cases include St. Kitts and South Caicos, Turks & Caicos Islands. Divers and snorkelers who see surgeonfish affected by BSS are encouraged to take underwater photos or video to document and record the location. Observations and questions may be sent to Dr. Pieter Johnson at the University of Colorado at pieter.johnson@colorado.edu.

For additional information, see: Kohl, Z. F., Calhoun, D. M., Elmer, F., Peachey, R. B. J., Leslie, K. L., Tkach, V. V., Kinsella, J. M. and P. T. J. Johnson (2019). Black-spot syndrome in Caribbean fishes linked to trematode parasite infection (Scaphanocephalus expansus). Coral Reefs 38: 917-930 (https://doi.org/10.1007/s00338-019-01819-3).

Photos by Cheyenna de Witt.