Kamimuria tibialis

Kamimuria tibialis (Pictet, 1841) Figs. 62−68 Material examined. Russia, Far East, Sakhalinskaya Oblast: 1♀, Kunashir Island, Tretyakovo settlement, 21.08.2013, coll. Yu. Sundukov. Egg. Oval rounded (Figs. 62, 67), total length 468−398 μm, equatorial width 337−301 μm (n=4). Collar stalked, rim flanged, and irregularly incised; sides of collar with irregularly spaced ridges (Fig. 64). Anchor is mushroom-shaped and the pedicel is very short (Figs. 62−64). The anchor surface is composed of pentagonal and hexagonal units with a few (2–6) globular bodies grouped inside and distributed over the whole surface of the anchor plate (Figs. 62–63). Chorion is covered with hexagonal FCI’s throughout with barely noticeable punctations inside; pits are obscure, shallow, and barely visible (Figs. 62, 65, 67). Micropylar row situated closely to anterior pole; micropylar canals are tunnel-shaped, long, and slightly stained; orifice rims are slightly raised (Figs. 62, 66). An external membrane bears single or double-large (larger than globular bodies on the anchor) mushroom bodies over each follicle cell impression (Figs. 67−68). Comments. The chorion structure of K. tibialis is significantly different from that of other Kamimuria species by faint pentagonal or hexagonal FCIs with barely noticeable punctations on the entire chorion surface. The chorion of K. exilis and K. lyubaetzi are covered with relatively large and deep pits of different sizes and shapes. Distribution. East Asian species that has an insular distribution from Kunashir Island (the Russian Far East) in the north to Kyushu (Japan) in the south and is considered endemic to the Japanese Archipelago. Kamimuria tibialis was included in the Korean checklist (Hwang & Murányi 2015, 2020) but probably does not occur on the peninsula and should be confirmed.