[Japanese name: Hotei-umi-hanekakushi]
(Figs. 2B; 3A, D & E)
Liparocephalus litoralis Kirschenblatt, 1938: 532 (original description; type locality: Bering Island (Komandor Islands); Maruyama & Ahn, 2000: 568 (redescription); Haga, 2022: 216 (additional records; biological notes).
Material examined. Japan: Hokkaidô: 1 female, 2 unsexed, Hamanaka-chô, Mochirippu, 12. IX. 1999, M. Maruyama (KUM); 5 males, 5 females, 67 unsexed, ditto, 28. IX. 2000, M. Maruyama (KUM, cYT); 1 male, 4 females, Nemuro-shi, Bettôga, Tengu-iwa, 2. VII. 2021, K. Haga (KUM, cYT).
Diagnosis. This species can be easily distinguished from all other Japanese species of the tribe Liparocephalini by its large, broad, and blackish body (Fig. 3A). This species is similar to L. brevipennis Mäklin, 1853 and L. humblei Klimaszewski, 2021 known from the eastern Pacific coast, but distinguished from them by the genital shape (see, Klimaszewski et al., 2021). These species have no clear sexual dimorphism in head size.
Habitat. This species is found inhabiting the seashore under stone and rock crevices (Maruyama & Ahn, 2000; Haga, 2022). Due to its restricted habitat, confined to a few coastal localities in the eastern Hokkaidô, Japan, it has been categorized as a “Data Deficient species (DD)” in “The 4 th Version of the Japanese Red Lists” (Ministry of the Environment, Japan, 2020).
Distribution. Japan: Hokkaidô; Russia: Kuril Islands (Matua Island), Komandor Islands (Bering Island).