Fabaeformiscandona subacuta (Ma & Yu, 2018)

Ma, Shunxin & Yu, Na, 2018, Freshwater ostracods (Crustacea) from Tiantong National Forest Park and Dongqian Lake, eastern China, with descriptions of two new species, Journal of Natural History 52 (27 - 28), pp. 1825-1868 : 1832

Fabaeformiscandona subacuta (Yang, 1982, in Hou et al., 1982)

( Figures 4a–c , 5 )

Candona (Candona) subacuta Yang Hou et al., 1982: 71 , pl. 17, figs. 3–5.

Candona japonica sp. nov. Okubo, 1990, 40–42, fig. 1(j–r).

Fabaeformiscandona japonica comb. nov. Schornikov and Trebukhova, 2001: 64. Fabaeformiscandona subacuta comb. nov. Schornikov, 2004: 458–465.

Material examined

Three females (ECNU20140907/TT23, 25; ECNU20150419/TT42) and three males (ECNU20140907/TT24; ECNU20150419/TT48; ECNU20150418/TT49) dissected.

Dimensions

(Female, n = 3) Length, 0.96–1.06 mm; height, 0.48–0.50 mm; width, 0.41 mm. (Male, n = 3) Length, 1.13–1.18 mm; height, 0.58–0.60 mm.

Brief description

Female, height of carapace equal to half of length. In dorsal view, LV overlapping RV with flanges both anteriorly and posteriorly. Two setae present on the end of first endopodal segment of A2. The penultimate segment of L7 divided. Claw Gp on UR equalling threequarters the length of claw Ga. Seta Sa small. More than two branches present on UR attachment.

Male, right palp of L5 large ( Figure 5a ). Left palp L-shaped with distal indentation ( Figure 5b ). Zenker organ with seven rows of chitinized rosettes. Outer lobe on Hp distally pointed ( Figure 5d ).

Distribution

This species is globally widespread and is thought to have originated in Asia ( Escrivà et al. 2012). In China, living examples of F. subacuta have been reported from Beijing ( Zhai et al. 2017), Zhejiang ( Escrivà et al. 2012) and Guizhou ( Kong et al. 2013).

Figures

Figure 4. (a–c) Fabaeformiscandona subacuta (Yang, 1982, in Hou et al., 1982). (a) ECNU20140907/ TT23, external view of RV (Female); (b) ECNU20140907/TT23, internal view of RV (Female); (c) ECNU20140907/TT24, external view of LV (Male). (d–f) Pseudocandona abei Smith and Janz, 2008. Female. (d) ECNU20140909/TT80, external view of LV; (e) ECNU20140909/TT80, internal view of RV; (f) ECNU20140909/TT8001, dorsal view. Scale bars: 100 μm.

Figure 5. Fabaeformiscandona subacuta (Yang, 1982). (a, b and d) (Male, ECNU20140907/TT24); (c) (Female, ECNU20140907/TT23). (a) Right prehensile palp; (b) Left prehensile palp; (c) Genital process; (d) Hp. Scale bars: 100 μm.