Pathological Changes in the Branchial Chamber Wall of Stingrays, Dasyatis spp., Associated with the Presence of Juvenile Gnathiids (Isopoda, Crustacea)

Abstract

Infestation of juvenile gnathiids, Gnathia sp., on the branchial chamber wall of two species of stingrays, Dasyatis akajei and D. matsubarai, caused proliferative inflammation of dermal tissue, and a heavy disruption of epithelia and smooth muscles. In addition to congestion of hemolytic blood cells, a prominent aggregation of heterophils, macrophages engaged in active phagocytosis, and plasma cells was also seen. It is of interest to note that evidence of a remarkable propagation of bacilli was encountered on the surface of the gnathiids and on the injured mucosal coat of the host fish. Besides a lot of blood sucking by gnathiids, bacterial infection might be one of the causes of host fish death or debility. © 1991, The Japanese Society of Fish Pathology. All rights reserved.