High prevalence of dermal parasites among coral reef fishes of Curaçao

Abstract

During expeditions to Curaçao in August and October of 2013, a large number of fish infected with dermal parasites was observed. Infected individuals presented black spots and white blemishes on their skin and fins that were easily observed by divers, and which have been associated with infections by trematodes, turbellarians, and protozoans (Cryptocaryon). In order to compare rates of infection across localities in the Caribbean, we conducted visual censuses of reef fish communities along 40 m2 belt transects in Belize (n = 35), Curaçao (n = 82), and Mexico (n = 80) over a 4-week period. Three affected individuals were recorded in Belize, 75 in Curaçao, and none in Mexico. Approximately 68 % of the infected individuals in Curaçao were surgeonfishes (Acanthuridae). There was no correlation between incidence of infection and species abundance (r2 = 0.03), or with functional traits (diet, mobility, schooling behavior, or position in the water column). The causes of the strikingly high incidence of dermal parasites in Curaçao and its consequences remain unknown. However, considering that parasites with complex life cycles have several hosts throughout their lives, and that past disease outbreaks have had severe consequences on communities of the Caribbean, we caution that coral reef ecosystems of Curaçao should be closely monitored.