Zapada quadribranchiata

Zapada quadribranchiata (Zhiltzova, 1977) (Fig. 6) Amphinemura quadribranchiata: Zhiltzova, 1977: 3. Zapada quadribranchiata: Zhiltzova. 2003: 312; Teslenko, 2009: 697; Teslenko & Zhiltzova, 2009: 108; Zwick, 2010: 81. Examined material. 1 female (HIST), China, Jilin Province, Baishan County, Changbaishan Mountain, 1283 m, 2023.VIII.2, 41.8265° N, 127.9362° E, leg. Weihai Li & Yao Zhang. Distribution. Previously known from Russian (Zhiltzova 1977) and Korea (Zwick 2010). The present study is the first record of this species for China. Remarks. We only collected a single female of this species; the cervical gills show that it belongs to Zapada (Fig. 6a). The rounded pregenital plate and the needle like subgenital plate are identical with the original illustrations of Z. quadribranchiata (Zhiltzova, 1977) (comparing Figs. 6b–6d with fig. 5 in Zhiltzova 1977). The rounded pregenital plate is somewhat straight after being cleared and needs gently pushed backward by a needle in order to observe the narrow subgenital plate (Fig. 6b), which can be seen through the cuticle of the pregenital plate (fig. 5, Zhiltzova, 1977). The two tiny dark markings near the genital opening were not depicted in the original illustrations. They may have been concealed by the anteriorly produced sternum 9 or possibly due to intraspecific variation. The paragenital is elongate and band like in lateral view which was not shown originally (Fig. 6c). The inner sclerite is triangular in shape with slightly sclerotized lateral extensions (Fig. 6d). We provide additional illustrations and the first description of inner sclerite of the adult female for aiding the recognition of this species from Jilin Province of northeastern China.