Postmetamorphic adult females of Lernaea cyprina- cea Linnaeus, 1758 (Copepoda: Lernaeidae) were col- lected from medaka, Oryzias latipes (Temminck and Schlegel, 1846) (Beloniformes: Adrianichthyidae), in an irrigation ditch connecting with the Okoe River, a tributary of the lower Katada River (the Bansho River system), at Saeki, Oita Prefecture, Kyushu, southern Japan. This represents the first record of L. cyprinacea from Oita Prefecture. In two of the six individuals of L. cyprinacea collected, peritrich-like ciliates were heav- ily attached to the surface of the trunk. Based on the literature published between 1935 to 2020, 21 nominal species of metazoan parasites (16 trematodes, one ces- tode, two nematodes, one branchiuran, and one cope- pod) have been reported from the prefecture.

ミナミメダカに寄生していた大分県初記録のイカリムシと 大分県産淡水魚の寄生虫相に関する知見(長澤和也・立川淳也・宮島尚貴・新田理人)