Immune responses in the bicolor damselfish, Pomacentrus partitus, and their potential role in the development of neurogenic tumours

Abstract

Bicolor damselfish on southern Florida reefs are commonly affected by a disease consisting of Schwann cell tumours. Several features of this disease, termed damselfish neurofibromatosis (DNF), indicate that the immune system of these fish may play an important role in the expression and rate of progression of the tumours. The majority of fish in the advanced stages of DNF showed abnormal, presumably degenerative, histological changes in both the spleen and kidney, suggesting that a general, non‐specific suppression of immune responses might be occurring. This hypothesis was supported by results of mitogen‐induced proliferation and mixed leucocyte responses in fish with DNF which indicated a near total failure of several functions of the immune system involving the pronephros and the spleen. A sparse infiltrate of granulocytes and monocyte/macrophages was seen in these tumours.