Squatinella longispinata (Tatem, 1867)

Squatinella longispinata (Tatem, 1867) View in CoL ( Fig. 3 View Fig )

ŪḦnjffiṻĒḆệ (ljạ) Stephanops longispinata Tatem, 1867: p. 252 , pl. 10,

figs. 1 - 3. Stephanops tripus Hudson, 1889: p. 36 , pl. 33, fig. 24. Stephanops unisetatus Hudson & Gosse, 1886: p. 76 , pl.

21, fig. 8. Stephanops unisetus Collins, 1872: p. 11 .

Material examined. Female, glycerol permanent slide ( NIBRIV0000919548 , NIBRIV0000919549 ). Soil from Seogwipo-si ( 33°25 ʹ 13.10 ʺ N, 126°50 ʹ 42.1 ʺ E), 09 Jan. 2022. Collected by Su-Jung Ji GoogleMaps .

Diagnosis. Body oval and hyaline, 100 μm in length. Head shield small and round. Two red eyespots on head. One very long, thin, and curved dorsal spine, 90 - 96 μm in length. Base of dorsal spine located in the middle of body. Foot with three pseudosegments. Two toes symmetrical, short, and conical, 9 μm in length. One short spine between two toes, 7 - 8 μm in length.

Distribution. Cosmopolitan ( Jersabek and Leitner, 2013).

Remarks. This species represents the first record of a Squatinella species with a long dorsal spine in Korea. Among the seven Squatinella species that possess dorsal spines, S. longispinata is most similar to S. longipila Luo & Segers, 2020 , sharing characteristics such as a long dorsal spine with a sharp tip, two separated toes, and three foot pseudosegments ( Koste 1978). However, S. longispinata can be distinguished from S. longipila by the shape of the dorsal spine base; S. longipila has a triangularly elongated base, whereas S. longispinata does not. Additionally, S. longispinata is the only Squatinella species with dorsal spines that also possesses a spine between its toes. Squatinella longispinata is also similar to S. curvispina Luo & Segers, 2020 and S. leydigii (Zacharias, 1886) , but these two species differ from S. longispinata by having two foot pseudosegments, fused toes, and a blunt tip on the dorsal spine.

Molecular analysis. Genomic DNA was extracted from a single specimen, and partial COI sequence was obtained (660 bp, PQ594391). The genetic distances among Squatinella species are presented in Table 2.

Family Notommatidae Hudson & Gosse, 1886 ṞÑḆệ⁂

Genus Notommata Ehrenberg, 1830 ṞÑḆệẃ