Prevalence and distribution patterns of tumors in bicolor damselfish (Pomacentrus partitus) on South Florida reefs

Damselfish neurofibromatosis (DNF) is a cancer affecting bicolor damselfish (Pomacentrus partitus) on reefs in South Florida, USA. Bicolor damselfish exhibiting DNF were observed on 18 of 19 reefs surveyed, with prevalence rates varying from 0.4 to 23.8% of the adult fish in these populations. These rates were very stable over 5 to 9 yr periods (1981 to 1989) on the two reefs monitored. High disease prevalence was associated with a high population density of large size-class fish and a population structure dominated by large fish. These patterns were observed both between and within reef populations. The distribution of cases within reefs was clustered rather than uniform or random. These findings are consistent with the hypothesis that DNF is distributed primarily via fish to fish (horizontal) transmission of an infectious agent. Disease patterns are not consistent with what would be expected to result from inherited (or vertically transmitted) or water-borne agents.