Paranais orientalis Sokolskaya, 1964

Lee, Jeounghee & Jung, Jongwoo, 2016, Faunistic survey on freshwater annelids from Korea, Journal of Species Research 5 (3), pp. 279-288 : 280

1. Paranais orientalis Sokolskaya, 1964 ( Fig. 1A )

Paranais litoralis orientalis Sokolskaya, 1964: 57 . Paranais orientalis Finogenova, 1982b: 39 .

Material examined. 2 individuals were collected from Gaesu­ri, Daehwa­myeon, Pyeongchang­gun, Gangwondo, E: 128°23′30.38″ N: 37°29′3.28″, 25 Sep 2014 (collector: Lee J). One individual mounted on a slide was deposited at NIBR ( KOSPIV 0000216639), and another preserved in 80% ethanol solution was deposited at LEG. Remarks. The genus Paranais can be easily distinguish­ ed from other naidine genera with that it has no eyes and dorsal chaetae start from segment V. This genus contains seven species. According to Finogenova (1982b), P. orientalis is a species in which the ventral chaetae begin in segment II and each ventral chaetal bundle is composed of 4-5 bifid chaetae ( Fig. 1A ) with the upper tooth of posterior chaetae being equal or slightly shorter than lower tooth. Mature individuals can be identified with the characteristics that it has 4 to 5 penial chaetae which are S-shaped with bifid end. Unfortunately, our specimen is immature. But other characteristics correspond to the description for species identification. This species could be mostly found in brackish water, but we collected them in freshwater. This is the first report of the genus Paranais from Korea.

World distribution. Europe, Sakhalin Island ( Russia), East Asia.

Figures

Fig. 1. A. Ventral chaetae of Paranais orientalis. B. A dorsal chaetal bundle of Prisitna breviseta. C. Ventral chaetae of P. forelii. D. A dorsal chaetal bundle of P. synclites. E. Ventral chaetae of Aulodrilus pluriseta. F. Dorsal chaetae of A. pluriseta. G. A penial sheath of Limnodrilus maumeensis. H. Chaetae of L. amblysetus. I. A dorsal chaetal bundle of Tubifex ignota. J. Dorsal chaetae of Psammoryctides albicola. K. Spermathecal chaetae of Varichaetadrilus vestibulatus. L. Ventral chaetae of Tasserkidrilus cf. acapillatus. Scale bars=A­D, G, K, L=10μm, E, F=20μm, H-J=1 μm.