Undulacandona cetus, Karanovic & Cho, 2017

Karanovic, Ivana & Cho, Joo-Lae, 2017, Phylogenetic position of the East Asian ostracod genus Undulacandona within Candonidae with description of four new species from subterranean waters of Korea, Zoological Journal of the Linnean Society 181, pp. 98-117 : 108-110

UNDULACANDONA CETUS SP. NOV.

( FIGS 11–13)

h t t p:/ / z o o b a n k. o r g / u r n:l s i d: z o o b a n k. o r g: a c t: 342FAC50-916D-4AD7-9D6F-E9E081132118

Type locality: River interstitial, Wolsong-ri, Jijeongm y e o n, Wo n j u - s i, G a n g w o n - d o, S o u t h K o r e a, 37°22 ′ 33.7 ″ N 127°51 ′ 22.6 ″ E, elevation 74 m, 22 May 2015, collector Joo-Lae Cho.

Etymology: ‘ Cetus ’ is the Latinized Greek word ‘ketos’ referring to a (sea) monster that killed Andromeda.

Diagnosis: Shell ornamented with fine stripes. LV and RV asymmetrical: LV subtriangular, RV subtrapezoidal. A1 five-segmented; A2 with all three exopodite setae short. L7 with incompletely subdivided penultimate segment. UR with elongated ramus and with curved claws, anterior claw slightly shorter than posterior, claws distally curved; posterior seta situated close to the distal end on the ramus. Hemipenis with lobe ‘a’ extending laterally.

H o l o t y p e: M a l e, d i s s e c t e d o n o n e s l i d e (N I B R I V 0 0 0 0 2 4 3 2 9 2), s h e l l o n S E M s t u b ( NIBRIV0000243282 ), collected from the type locality .

Description: Male. L of shell 0.84 mm. Greatest H situated in front of middle L, equalling 52% of L on LV ( Fig. 11B) and 47% on RV ( Fig. 11A). LV subtriangular in lateral view, with dorsal margin arched and sloping towards anterior and posterior ends. Anterior and posterior margins rounded, and equally wide. On RV, dorsal margin flat around middle L, inclined towards posterior and rounded towards anterior end. Posterior margin narrower than anterior one. Ventral margin straight. Surface covered with fine stripes ( Fig. 11C, D) and with sensory setae exiting from pores. Pores rimmed. Surface setae of various lengths. Inner calcified lamellae and line of concrescence narrow ( Fig. 12A, B).

A1 ( Fig. 12D): Five-segmented, same as in other three species. Peculiar extension on posterior margin of the second segment pronounced.

A2 ( Fig. 12C): Penultimate segment subdivided with male sensory bristles. Exopod consisting of three short setae. Endopod five-segmented. Aesthetasc Y slightly longer than posterior margin of the first endopodite segment. Same segment with two setae on postero-distal margin: one long and other very short. Beside large male sexual bristles margin between second and third endopodal segment also with one anterior (short) and one posterior (longer) seta. Claws G1 and G3, as well as z3 seta reduced, while G2 claw, and z1 and z2 setae long and stout. Terminals segment with long Gm and short Gm claw. Aesthetasc y3 long.

Md and Mxl same as in other three species.

Prehensile palps ( Fig. 12F, G): Palp developed only on one side of the body. The other ( Fig. 12G) with deformed endopodite. Setae ‘b’ and ‘d’ as well as one exopodal seta observed on both L5 ( Fig. 12H). No spine-like process proximally on the palp.

L6 ( Fig. 12I): Five-segmented. Basal and first endopodal segments without any seta. Second and third endopodal segments with one short seta each. Terminal segment with two short setae and a long, curvy, claw.

L7 ( Fig. 12E): Four-segmented. Penultimate segment incompletely subdivided. Basal segment with all three setae present. Only seta ‘g’ present. Terminal segment with two short and one long seta. L ratio between two short setae equalling 3:1.

UR ( Fig. 13B)L: Ramus elongated, posterior setae situated close to the distal end on the ramus. Both claws well developed, anterior longer than posterior and both claws curved. Anterior seta reaching only 1/3 of anterior claw. L ratio between anterior margin of the ramus, anterior claw, and posterior claw equalling 1.3:1:1.1. Attachment short ( Fig. 13C).

taken with caution because such case has never been reported in ostracods and may be the result of some abnormality. Due to the fact that we only had a single male, we could not check the variability of this character.