Batucypretta, Victor & Fernando, 1981

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 : 211-212

Batucypretta sp.

Figures 5 .

Material examined: Two females from YND1, two females ( ECNU 20170415/HN25–26) dissected.

Dimensions: Female, width 0.251 mm; RV, n = 2, length 0.411 mm, height 0.225 –0.229 mm; LV, n = 1, length 0.417 mm, height 0.236 mm.

Description: Carapace sub-oval-shaped. LV overlapping RV ventrally. Anterior margin more rounded than posterior. Dorsal margin arched. LV with outer list along anterior margin (arrow c in Fig. 5A ). One inner list running close to inner margin of posterior calcified inner lamella and in median part of anterior calcified inner lamella. Calcified inner lamella wider anteriorly than posteriorly. LV calcified inner lamella with inner list anteriorly and in postero-ventral region ( Fig. 5B ). Surface of valves pitted in central area (arrow a in Fig. 5A ). Anterior and posterior margins of both valves with incomplete septa (not reaching line of concrescence) (arrow b in Fig. 5 B–D). Five long natatory setae on A2 well-developed, slightly exceeding tips of terminal claws, and sixth one shorter. Terminal segment of Mx palp cylindrical. Two tooth-bristles on third endite smooth ( Fig. 5E ). L6 four-segmented, penultimate segment undivided, with f seta exceeding end of terminal segment. Seta h3 tiny ( Fig. 5F ).

Distribution: This species was only found in Sanya on Hainan Island.

Remarks: Due to the sub-oval-shaped carapace with the incomplete septa along the free margins, this species was identified as a member of the subfamily Batucyprettinae , genus Batucypretta . All specimens show some decay, which occurred during transport to the laboratory, and remaining characters (part of the A2, Md, Mx, part of the L6 and L7) are not sufficiently preserved to fully describe this species. The specimens are adults as shown by the presence of 5+1 natatory setae on the A2 and the septa along the free margins ( Smith & Martens 2000). Only one previous species, Batucypretta paradoxa Victor & Fernando, 1981a , has been reported in this genus, but it differs in the following characters: the length of the carapace of Batucypretta sp. (0.411 –0.417 mm) is smaller than that of B. paradoxa (0.490 –0.550 mm); the h3 seta on the L6 is present in adult Batucypretta sp., but absent in adult B. paradoxa (this seta exists in preadult instars); both tooth-bristles on the third endite of the Mx are smooth in Batucypretta sp., while they are toothed in Batucypretta paradoxa ( Victor & Fernando 1981a) .

Figures

FIGURE 5. Batucypretta sp. Female. A, ECNU20170415/HN26; B–F, ECNU20170415/HN25. A, dorsal view, anterior to the right; B, internal view of LV; C, internal view of LV; D, internal view of RV; E, Mx; F, part of L6. Arrow a: pits on central part; arrow b: incomplete septa; arrow c: outer list. Scale bars: 100 μm.