Morphological characteristics of hemocytes in parasitic copepod Acanthochondria eptatreti (Chondracanthidae, Poecilostomatoida) from hagfish Eptatretus burgeri off Shimonoseki (Hibiki-Nada), Japan, were histologically examined by light microscopy. Only a single type of hemocyte, basophilic granulocyte, was observed not only in the hemal space, but also on/in the connecting tissue of A. eptatreti. The morphology of the hemocytes, especially cytoplasmic granules, were similar to those of other parasitic copepods, Pseudocaligus fugu (Siphonostomatoida) and anchor worm Lernaea cyprinacea (Cyclopoida), hemocyte-like granular cells of the copepods with free life style (Tigriopus japonicus (Harpacticoida) and Cyclops vicinus (Cyclopoida)) in which lack circulating hemocytes. About 12% of hagfish were infected with A. eptatreti. This is the first recorded occurrence of A. eptatreti infection on hagfish in Japan.
Acanthochondria eptatreti
Copepoda
Crustacea
hemocyte
morphology