サッパノギンカの寄生による阿蘇海産マイワシの体表損傷および肥満度への影響

抄録

Ovigerous females of the cymothoid isopod Anilocra clupei were found around the opercula and dorsal fin of the Japanese sardine Sardinops melanostictus captured in Aso-kai Lagoon, Kyoto Prefecture, Japan. The attachment sites showed loss of scales and pigmentation, along with ulceration. The estimated infection prevalence, intensity, and mean intensity of A. clupei, including fish possessing presumably parasitic wounds, were 41%, 1–2, and 1.01, respectively. The infection prevalence, including individuals possessing only parasitic wounds, tended to be higher in the smaller-sized fish and they were also significantly less obese. When assessing economic impact of A. clupei, fish without isopod infection but showing parasitic wounds should also be considered.