Strange symptoms in reef fish

Strange symptoms in reef fish

Recently a large number of fish species has been observed carrying signs of what could be a disease. Two types have been observed and herbivorous fish seem most affected. The first “disease” was historically observed on surgeonfish (A. bahianus), but is now also occuring on several species of grunts and hamlets. Indiviuals affected are covered by dark, round patches, usually dark grey/ black in color, that can occur all over their body. Examples of this “disease” are shown  in the first two pictures below. In addition to this “dark spot disease”, many other species (including foremost various parrotfish species, but also cowfish, goatfish) have been observed covered by white specks that occur on the fins of these species, but also on their bodies. Pictures of this “white dot disease” are shown in pictures 3 to 6 below, where the last picture shows a redband parrotfish (S. aurofrenatum) where these dots have multiple colors ranging from white to brown to black. In some locations, none of these “diseases” is observed, but in others nearly 30% of the fish are seen carrying signs of either “disease”. This to teh best of my knowledge has not been observed earlier on Curacao.

Any insight as to what is going on here is greatly welcomed. Suggestions and ideas can be send to Mark Vermeij ( )

Examples of “dark spot disease”:



Examples of “white dot disease”:





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