Dermal fibroma in a redband parrotfish, Sparisoma aurofrenatum (Valeciennes)

A redband parrotfish, S. aurofrenatum (Valenciennes), with a tumor on the side of the body, ventral to the dorsal fin, was observed from an underwater laboratory in the Caribbean region, U.S. Histological examination revealed a fibroma of randomly oriented bundles of fibrous tissue covered by normal skin. The tumor tissue was denser than the normal tissues. This is the first reported neoplasm for a Scaridae, or for a fish collected in the Caribbean region. No parasites were associated with the tumor; no attempt was made to establish a viral aetiology. Chemical carcinogens cannot be eliminated as a cause. The possibility of a fish tag being associated was rejected.