Candonopsis, Vavra, 1891

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 : 208

Candonopsis ? sp.

Figures 2 and 3 .

Material examined: One female from 11JFL28, one female ( ECNU 20171114/HN46) dissected.

Dimensions: Female, RV, n = 1, length 1.096 mm, height 0.559 mm.

Description: Lateral view of carapace roughly trapezium shaped, central-dorsal margin straight, posterior end wider than anterior. Maximum height at mid-length. Surface of valve pitted in marginal areas and slightly pitted in central area ( Fig. 2A ). Calcified inner lamella wide in anterior area, narrower in postero-ventral area. Aesthetasc Y on A2 long, almost reaching end of first endopodal segment. Claw G2 on A2 short, less than half length of claw G1 ( Fig. 3A ). Length of terminal segment of Md palp equaling five times its width ( Fig. 3B ). Seta Sa on UR very short. Claw Gp approximately 4/5 length of claw Ga. Claw Gp with a distinct spine at mid-length ( Fig. 3C ).

Distribution: One specimen of this species was found in Jianfengling National Forest Park on Hainan Island.

Remarks: Only one specimen was found with incomplete soft parts. The wide anterior calcified inner lamella indicates that this specimen is an adult. This specimen is morphologically close to species in the genera Marococandona Marmonier et al., 2005 and Candonopsis (Candonopsis) Vávra, 1891 with the seven-segmented A1 and the long terminal segment of the Md ( Karanovic 2012; Marmonier et al. 2005; Marmonier 2006). The slender end of aesthetasc Y on A2 and the median tooth on the Gp of UR are similar to Candonopsis species. The trapezium shape of the valves and the reduced number of t setae on A2 are similar to Marococandona species. There are two species in Marococandona : M. danielopoli Marmonier et al., 2005 and M. nicolae Marmonier et al., 2005 . They are different from the present specimen from Hainan in the following characters: the length of the carapace (0.530 –0.550 mm) is much smaller than in the present specimen (about 1.096 mm) and reticulation covers the entire surface of the carapace in M. nicolae and in the central part in M. danielopoli , contrasting with the pits being present in areas except the central part in the present specimen. The claw Gp of the UR varies in these three species: it is normally developed in M. danielopoli , absent in M. nicolae and normally developed with a spine at mid-length in the Hainan species, which is more similar to some species in Candonopsis . Provisionally, this species is placed in the genus Candonopsis , but further material is required to clarify its taxonomic affinities.

Figures

FIGURE 2. Candonopsis? sp. Female. ECNU20171114/HN46. A, external view of RV; B, internal view of RV. Scale bar: 100 μm.

FIGURE 3. Candonopsis? sp. Female. ECNU20171114/HN46. A, A2; B, part of Md palp; C, UR; D, UR attachment. Scale bars: 100 μm.