Nonmarine ostracods (Crustacea) from South Korea, including a description of a new species of Tanycypris Triebel (Cyprididae, Cypricercinae) Author Chang, Cheon Young Author Lee, Jimin Author Smith, Robin J. text Zootaxa 2012 3161 1 19 journal article 45652 10.5281/zenodo.214227 63450022-4703-4d83-966c-bb866ea9a5fb 1175-5326 214227 Tanycypris centa n. sp. ( Figs 2 D–H, 3 & 4) Material examined. Twelve females from the lower reaches of the Hyeongsan River, Yangdong, Gyeongju (35°59′16″N, 129°15′21″E) (locality 8 on Fig. 1 ), 10 October 2010 . Type material. Holotype—dissected female (NIBRIV0000243259). Paratypes—dissected female (NIBRIV0000243260), whole female (NIBRIV0000243262), female valves (NIBRIV0000243261). Type locality. The lower reaches of the Hyeongsan River, Yangdong, Gyeongju (35°59′16″N, 129°15′21″E) (locality 8 on Fig. 1 ). Etymology. The specific name centa is taken from the Latin cento , meaning ‘patchwork’, which refers to the purple patches on the carapace. This character has so far not been reported for other congeneric species. Diagnosis. Carapace elongate, with height:length ratio of 0.40–0.43, maximum height at anterior quarter. Calcified inner lamella very wide with slight bulge inwards in postero-ventral region. Carapace with large irregular purple patches. Antennule with well-developed Wouters Organ, similar in morphology to Rome Organ, both with bulge on stem. Caudal ramus very long and relatively slender. Description of female. Carapace ( Fig. 2 D–H) length 1103–1145 µm, height 458–470 µm, elongate with height:length ratio of 0.40–0.43. Anterior margin more inflated than posterior margin, dorsal margin almost straight, ventral margin slightly sinuous, maximum height at anterior quarter. Calcified inner lamella very wide, with slight bulge inwards in postero-ventral region. Fused zone very narrow, with short marginal pore canals. Mandibular scars large and well-developed, adductor scars weakly defined, consisting of four, elongate and narrow scars. LV with groove along inner ventral margin. Dorsal view ovoid, maximum width approximately at midlength, anterior and posterior margins similar in outline. Carapace strongly coloured with irregular purple patches ( Fig. 3 B). An1 ( Fig. 3 C) with eight segments, first two of which fused together forming large, elongate base. First segment with well-developed Wouters organ, with slight bulge on stem and disc-shaped terminal end ( Fig. 3 D). Second segment with two long apical-ventral setae. Third segment short, with short apical-dorsal seta and welldeveloped Rome organ, with prominent bulge on stem and flattened, disc-shaped distal end ( Fig. 3 E). Fourth segment elongate with one short apical-dorsal seta and one short apical-ventral seta. Fifth segment with two short apical ventral setae, and two long apical-dorsal setae. Sixth segment with two long apical setae, one medium-length apical seta and one short apical seta. Seventh segment with four long and one very short apical setae. Final segment with one long, one medium-length and one short apical setae and aesthetasc ya . An2 ( Fig. 3 F & G) with long Y aesthetasc. Natatory setae long, reaching to distal end of claws. Claw G2 long, slightly shorter than G1 claw. Claw Gm slender, approximately three-fourths the length of GM . Md palp ( Fig. 3 H) elongate. First segment with long, slender alpha seta ( Fig. 3 J). Second segment with short, wide, stubby beta seta covered with many stiff setules ( Fig. 3 J). Third segment with slender gamma seta, with setules along distal half ( Fig. 3 J). Md coxa large and robust, with seven teeth on endite ( Fig. 3 I). FIGURE 2. A–C, Bradleycypris vittata (DB40011). A, right lateral view of whole carapace. B, dorsal view, anterior to right. C, anterior view. D–H, Tanycypris centa n. sp. D, right lateral view of whole carapace (NIBRIV0000243261). E, left valve, internal view (NIBRIV0000243261). F, detail of ventral margin of left valve (NIBRIV0000243261). G, right valve, internal view (NIBRIV0000243261). H, dorsal view, anterior to right (NIBRIV0000243261). I–J, Cavernocypris coreana elongata (DB40012). I, left valve, internal view. J, right valve, internal view. K–L, Cypridopsis vidua . K, dorsal view, anterior to right (DB40013). L, left valve, internal view (DB40014). Scale bar = 306 µm for A–C, 430 µm for D–E, G–H, 91 µm for F, 239 for I–J, and 266 µm for K–L. FIGURE 3. Tanycypris centa n. sp. A, left valve, internal view (NIBRIV0000243261). B, whole carapace, right lateral view. C, An1 (NIBRIV0000243259). D, Wouters organ (NIBRIV0000243259). E, Rome organ (NIBRIV0000243259). F, An2 (NIBRIV0000243259). G, detail of An2 (NIBRIV0000243259). H, Md palp (NIBRIV0000243259). I, Md coxa (NIBRIV0000243260). J, alpha, beta and gamma setae of Md palp (NIBRIV0000243259). FIGURE 4. Tanycypris centa n. sp. A, Mx (setae on endites not drawn) (NIBRIV0000243259). B, L5 (NIBRIV0000243259). C, L6 (NIBRIV0000243259). D, L7 (NIBRIV0000243259). E, CR (NIBRIV0000243259). F, CR attachment (NIBRIV0000243259). Mx ( Fig. 4 A) with two-segmented palp, first segment with six apical setae on outer edge and one sub-apical seta towards outer edge. Second segment elongate and curved, apically with two stout setae and four shorter setae. Spines of third endite serrated towards distal ends. Branchial plate with 18 normal rays and four reflexed rays. L5 ( Fig. 4 B) relatively large and elongate, with two a setae, and b and d setae present. Endite with approximately 12 apical setae. Palp (endopodite) elongate with three setulous apical setae of variable lengths. L6 ( Fig. 4 C) relatively small and stout. Seta d1 on first segment longer than d2 . Seta e of second segment and seta f of third segment both long and stout. Seta g of fourth segment and setae h1 and h3 of fifth segment all relatively long and sub-equal in length. Claw h2 stout with well-developed serration distally. L7 ( Fig. 4 D) with four segments, first of which with medium-length d1 , d2 and dp setae. Second segment with e seta. Third segment with f seta at approximate mid-length point. Final segment forming compact pincer arrangement with long h3 seta and short, curved h2 seta. CR ( Fig. 4 E) very long, typical of genus, slightly sinuous along length. Seta Sp short and with setules distally. Claw Gp long and stout, claw Gp half length of claw Ga . Both claws with well-developed serration. Seta Sp long, approximately three-quarters the length of Ga . CR attachment ( Fig. 4 F) stout, curved stem with triangular Triebel loop distally. Dorsal branch, db , strongly curved, ventral branch, vb , short and rounded in outline. Remarks. Males unknown. Of the eight species in the genus, Tanycypris centa n. sp. most closely resembles T. siamensis Savatenalinton & Martens, 2009 and T. pellucida Klie, 1932 as figured by Okubo (1972 as Strandesia camaguinensis ; 1990b; 2000; 2004). Okubo’s ( op. cit. ) figures and plates more closely resemble T. siamensis rather than Klie’s (1932) original description of T. pellucida , which has much narrower calcified inner lamellae. Differences between T. siamensis and T. centa n. sp. include the following: the posterior margin of the carapace is more tightly curved and the dorsal margin straighter in T. centa n. sp. compared with T. siamensis ; T. centa n. sp. has a well-developed Wouters organ (missing in T. siamensis ); the caudal ramus is noticeably thinner in T. centa n. sp. compared with that of T. siamensis ; T. siamensis is a uniform pale brownish-yellow, lacking the distinctive purple patches on the carapace seen in T. centa n. sp. (Savatenalinton pers. comm.). In their generic revision of the Cypricercinae , Savatenalinton & Martens (2009) included the absence of the Wouters organ as a diagnostic character of the genus Tanycypris . However, this is based on only one species in the genus; it is unknown if other species in the genus, including the type species, have Wouters organs or not. Our species has a well-developed Wouters organ, but in all other respects fits into the genus Tanycypris (and not any other genera in the Cypricercinae ). We therefore suggest that the absence of the Wouters organ is not a useful characteristic for the diagnosis of the genus.