Schellencandona tea, Karanovic, Ivana & Lee, Wonchoel, 2012

Karanovic, Ivana & Lee, Wonchoel, 2012, A review of candonid ostracods (Crustacea: Ostracoda: Podocopida) from East Asia, with descriptions of five new species from South Korea *, Zootaxa 3368, pp. 7-49 : 32-35

Schellencandona tea sp. nov.

( Figures 15–16 )

Etymology. The species is named after the Chinese word “ tea ”, later on Latinized and incorporated into the plant genus name Thea Linnaeus, 1753 (now a junior synonym of the genus Camellia Linnaeus, 1753 ), a genus of the tea family Theaceae D. Don, 1825 .

Material examined. Holotype female (soft parts dissected on one slide, shell kept on micropaleontological slide NIBRIV0000245058), from (type locality) South Korea, Gyungsangbukdo, Sanggu, Young river (freshwater), interstitial, 36 0 31’42”N, 128 0 14’02”E; 01/07/2010, collector Joo-Lae Cho. One female (soft parts dissected on one slide, shell not preserved NIBRIV0000245059), from South Korea, Gyungsangbukdo, Uljin, Geunnam river, interstitial, 36 0 57’52”N, 129 0 22’52”E; 03/08/2010, collector Joo- Lae Cho.

Description. Female: Carapace reniform in shape ( Figure 15 A, B) with the greatest H lying slightly behind middle L, equaling 44% of total L. Size: L= 0.56 mm. Dorsal margin almost evenly rounded and slightly more curved towards posterior and inclined towards anterior end. Anterior and posterior margins both broadly rounded and equally wide. Ventral margin almost straight along entire L. Calcified inner lamella narrow on both ends, anteriorly equaling 13%, posteriorly less than 1% of total L. Fused zone also very narrow and marginal pore canals short, straight and denser anteriorly than posteriorly. Surface of shell covered with fine setulae, originating from small, but clear wart-like structures. No other surface ornamentation present. LV overlapping RV on all free margins. Selvage thin and peripheral.

A1 ( Figure 16 B). Appendage 7-segmented. First segment with only one seta anteriorly and two posteriorly. Anterior seta situated more proximally, distal one missing. Posterior setae originate from same (or very close) spot. All setae pappose. Second segment with one anterior pappose seta, not reaching distal end of fourth segment. Third segment with one anterior pappose seta not reaching distal margin of fifth segment. Fourth segment with one short posterior seta (slightly exceeding distal end of fifth segment), and one anterior, longer seta (exceeding distal end of terminal segment); all these setae pappose. Fifth segment with same chaetotaxy as fourth one. Penultimate segment with total of four setae; posteriormost seta “d” absent. Alpha seta not reaching distal end of terminal segment. Seventh segment with posterior, claw-like seta twice as long as terminal segment, one aesthetasc (ya) of the same L, and two longer pappose setae. L ratio of five distal segments equaling: 1: 1.25: 1.4: 1.75: 2. Rome and Wouters organs not present.

A2 ( Figure 16 A). Basal segment with total of three setae of subequal L, one situated dorsally and two ventrally on segment. Protopod with a distally pappose seta, not exceeding distal margin of second endopodal segment. Protopod with rows of spines posteriorly. Exopod consisting of plate carrying one long (almost reaching distal end of first endopodal segment) and two short, pappose setae. Endopod 3-segmented. First endopodal segment with long aesthetasc “Y” and antero-ventrally with two setae. Second segment with one medio-dorsal seta, all “t” setae visible (exceeding distal end of terminal segment). Same segment medio-ventrally with short aesthetasc y1. Third endopodal segment with claws G1, G2 and G3; G2 being half as long as G1. Seta z1 not transformed in claw, slightly exceeding distal end of terminal segment, the other two also seta-like and of same L. Terminal segment with one long claw, GM and one short claw, Gm (3 times longer than terminal segment). Terminal segment also armed with aesthetasc y3 (2.5 times as long as terminal segment) and one thin seta accompanying y3. Claws very gently serrated.

Md ( Figure 16 C). First segment of palp with one plumose seta (S1), one pappose, short seta (S2), a short alpha seta, and one additional seta situated proximally on segment. Second segment dorsally with two setae, reaching distal end of following segment, ventrally with three plumose setae originating from a small plate and one plumose seta; beta seta short and smooth. Penultimate segment dorsally with three almost equally long setae, gamma seta faintly pappose, and three additional setae, one of which originates medially and two ventrally. Terminal segment with two strong, well-sclerotized claws (lateral one serrated distally, medial plumose) and two setae more ventrally.

Mxl and L5. Same as in previous species.

L6 ( Figure 15 D). Basal segment with one seta (d1). Endopod 4-segmented. Setae “e”, “f”, and “g” all relatively short and pappose. Terminal segment with distal claw and two lateral, short setae (h1 and h3). Distal claw 1.2 times longer than combined L of three distal segments.

L7 ( Figure 15 E). Basal segment with “d1” and “dp” setae, “d2” missing. Endopod 3-segmented, and only “g” seta present distally. Terminal segment armed with two long and one short seta. L ratios between three “h” setae equaling: 1: 2.4: 2.8.

UR ( Figure 15 C). Relatively short and stout, symmetrical rami. Posterior seta not long but exceeding posterodistal margin of the ramus. Anterior seta much shorter and only ¼ L of anterior claw. Both claws strongly serrated. L ratio between anterior margin, anterior claw, posterior claw and posterior seta equaling: 3.25: 2.4: 2: 1. Genital field ( Figure 15 C) rounded and without any projections.

Male. Unknown.

Remarks and affinities. The genus Schellencandona was erected to accommodate Candona -like species with seta “d2” missing on the L7, a hemipenis with flat (not strongly sclerotized) “M”-piece, three setae on the second segment of Md-palp internally and with two long and one short seta on the terminal segment of the L7, and 4+2 rows of spines on the Zenker organ ( Meisch 1996). At the moment, the genus comprises six Recent species: S. belgica ( Klie, 1937) , S. insueta ( Klie, 1938) , S. schellenbergi ( Klie, 1934) ; S. simililampadis ( Danielopol, 1978) , S. triquetra ( Klie, 1936) , and S. yakushimaensis Smith & Kamiya, 2006 . Most of the species have been found in subterranean waters of Europe ( Klie 1934, 1936, 1937, 1938; Danielopol 1978; Meisch 1996, 2000), while S. yakushimaensis Smith & Kamiya, 2006 was described from a temporary water body in Japan ( Smith & Kamiya 2006). With the exception of the Japanese species, all others are known from both male and female specimens. Of the new Korean species we also collected only female specimens. Despite the lack of males, we decided to place it in the genus Schellencandona , based of its small size and the chaetotaxy of the L7. It differs from the European species by the carapace shape, which is trapezoidal to subtrapezoidal in lateral view in the European species, while the dorsal margin in the new species is rounded and the carapace is more bean-shaped. Schellencandona tea sp. nov. is very closely related to S. yakushimaensis , but differs in the chaetotaxy of the A1 (antero-distal seta on the first segment of A1 is missing in the Korean species and there is only one seta on the fourth and fifth segments), as well as in seta “g” on the L6 and seta “h1” on the L7, which are both shorter in the Japanese species. Furthermore, the calcified inner lamella is wider in S. yakushimaensis than in S. tea .

Figures

FIGURE 15. Schellencandona tea sp. nov., holotype (female): A, RV, outside view; B, LV, outside view; C, UR; D, L 6; E, L 7. Scales = 0.1 mm.

FIGURE 16. Schellencandona tea sp. nov., holotype (female): A, A 2; B, A 1; C, Md-palp. Scales = 0.1 mm.