Fig. 2. Mature (above) and immature (below) worms of Pennella sp.
Fig. 1. Pennella sp. (arrow) hanging the body surface of tiger puffer.
(Photos by K. Momoyama)
| Parasite | Pennella sp. |
|---|---|
| Taxonomy | Arthropoda, Copepoda, Pennellidae |
| Host | Tiger puffer (Takifugu rubripes) |
| Infection site | Skin |
| Clinical sign | A parasite on the skin is visually observed (Fig. 1). |
| Parasitology | Three types of parasites are observed. Lengths of the body excluding the head part (4-5 cm in all types) are 7.5 cm in the biggest one, 5.4 cm in the middle-sized one and 3.4 cm in the smallest one (Momoyama and Tensha, 2006). The body is black in the biggest and the smallest types, reddish in the middle-sized type (Fig. 2). It is unclear whether these 3 types are the same species. |
| Pathology | These parasites may be pathogenic since the muscle tissue around the parasite head exhibits reddened lesion and inflammation. The parasite head sometimes reaches at the liver (Momoyama and Tensha, 2006). |
| Health hazard | Since this parasite is not infectious to human, it is harmless in food hygiene. |
| Diagnosis | Check the morphology of the parasite on the skin. |
| Other information | This Pennella parasitizes the wild tiger puffer from the Pacific Ocean (east from the Tokushima Prefecture), while they are not observed in the Sea of Japan or the East China Sea according to the interview in the fish market in the Yamaguchi Prefecture (Momoyama and Tensha, 2006). |
| References | .Momoyama, K. and K. Tensha (2006): Ugly-looking parasitic infections and
other abnormalities of wild fish and shellfish caught in the coastal or
inland waters around or in Yamaguchi Prefecture. Bull. Yamaguchi Pref. Fish. Res. Ctr.,
4, 143-161. |