Parasite	Capillaria sp.
Taxonomy	Nematoda, Adenophorea, Capillariidae
Host	Daggertooth pike conger (Muraenesox cinereus)
Infection site	Between the peritoneum and the muscle
Clinical sign	Black foreign bodies are observed in the muscle (Fig. 1). These bodies are aggregations of bistered spots (Fig. 2).
Parasitology	These spots are eggs of a parasite (Fig. 3). The fusiform eggs, ca. 65 mm in length, have a thick shell and 2 plug-like structures at the both ends (Fig. 4). These morphological features indicate that they are eggs of the nematode belonging to the genus Capillaria. However, the parasite cannot be identified because of no availability of the main body of the parasite.
Pathology	The pathogenicity to fish may be low.
Health hazard	Capillaria philippinensis, a parasite of fish, is known to parasitize human. However, Capillaria sp. in daggertooth pike conger is different species from C. philippinensis because development of larvae is not observed inside the eggs. Therefore, it is probably harmless in food hygiene.
Diagnosis	The parasite was presumptively diagnosed by size and morphological observations of eggs.
References	None

Fig. 1. Several foci (arrows) in the fillet of Daggertooth pike conger

(Photos by J. Araki)

Fig. 4. Plug-like structure (arrows) at the both end of eggs
of Capillaria sp

Fig. 3. Aggregates of parasite eggs.

Fig. 2. Parasite foci (arrows) in the muscle.