6. Dero digitata (Müller, 1774) (Fig. 6)

ẺãḃậȃmǵÑ (ṵAE)

Nais digitata Müller, 1773: 22 .

Dero digitata (Müller) Sperber, 1958: 49 .

Material examined. Boeun-gun (36°19′58.49″N, 126°39′ 35.87″E), Korea; collected by JH Lee on 20 May 2016.

Deposition. NIBRIV0000879697.

World distribution. Cosmopolitan.

Diagnosis. Dorsal bundles onward from VI; mostly one hair chaeta, and one needle chaetae. Ventral chaetae II - V by four to five per bundle, with 1.5 times longer upper tooth (Fig. 6A). Branchial fossa with antero-dorsal margin entire, convex and ciliated and a postero-ventral margin prolonged into a non-ciliated rounded lip. Foliate gills four pairs, one pair dorsal and small, one pair lateral and two pairs ventral (Fig. 6B).

Remarks. The chaeta of our specimen is a bit shorter than previous studies (Timm, 2009). It is too early to predict because there is only one confirmed sample. After more samples are taken, they should be compared.