Chrissia formosa ( Klie, 1938 )

Ma, Shunxin & Yu, Na, 2020, Freshwater ostracods (Crustacea) from Hainan Island, southern China, with description of a new species, Zootaxa 4767 (2), pp. 201-243 : 225-226

Chrissia formosa ( Klie, 1938)

Figures 19–20 .

1938b Stenocypris formosa n. sp. — Klie: 28 –30, figs. 8–11.

1974a Chrissia formosa ( Klie, 1938) — Okubo: 5.

Material examined: Six females and five female valves from11DZ17, one female ( ECNU 20171114/HN09) dissected; two females from WN6.

Dimensions: Female, LV, n = 2, length 1.562 –1.586 mm, height 0.631 –0.635 mm.

Description: In lateral view, carapace elongated. Greatest height posterior of mid-length. Dorsal margin arched. Ventral margin slightly concave. Calcified inner lamella anteriorly wide. Septa on margins of carapace absent ( Fig. 19A ). Eggs visible through pellucid valve (arrow a on Fig. 19A ). Five long natatory setae on A2 exceeding tips of terminal claws, and one short almost reaching middle of next segment ( Fig. 20A ). Both tooth-bristles on third endite of Mx slightly toothed. L6 five-segmented, with two d setae on basal segment ( Fig. 20B ). UR asymmetrical. UR attachment with basal triangular reinforcement ( Fig. 20E ). Seta Sa shorter than 1/2 length of claw Ga, claw Gp shorter than 1/2 length of claw Ga ( Fig. 20 C–D). Stem of left UR smooth ( Fig. 20D ), and right one with continuous line of denticles ( Fig. 20C ).

Distribution: This species has been previously reported from Japan ( Okubo 2004; Smith et al. 2011), India ( Karuthapandi et al. 2014), the Philippines ( Victor & Fernando 1981b), Thailand ( Savatenalinton & Suttajit 2016) and Taiwan in China ( Klie 1938b). During this study, this species was found in Danzhou and Waning on Hainan Island.

Remarks: The maximum height of the valve is situated at mid-length in Klie (1938b) and Victor & Fernando (1981b). Hainan specimens are more similar to specimens found in Japan by Okubo (2004) and Smith et al. (2011), with maximum height situated slightly posterior of mid-length ( Fig. 19 ).

Figures

FIGURE 19. Chrissia formosa (Klie, 1938a). Female. ECNU20171114/HN09. A, external view of LV; B, external view of LV. Arrow a: eggs. Scale bar: 100 μm.

FIGURE 20. Chrissia formosa (Klie, 1938a). Female. ECNU20171114/HN09. A, A2; B, L6; C, right UR; D, left UR; E, UR attachment. Scale bars: 100 μm.