Daphnia koreana, Kotov & Garibian & Bekker & Taylor & Karabanov, 2021

Kotov, Alexey A., Garibian, Petr G., Bekker, Eugeniya I., Taylor, Derek J. & Karabanov, Dmitry P., 2021, A new species group from the Daphnia curvirostris species complex (Cladocera: Anomopoda) from the eastern Palaearctic: taxonomy, phylogeny and phylogeography, Zoological Journal of the Linnean Society 191 : -

DAPHNIA KOREANA SP. NOV.

( FIGS 9–13)

LSID: urn:lsid:zoobank.org:act:6ABA6D42-8CC6-4342-A7A5-2EC0F4732A43

Daphnia sinevi Kotov, Ishida & Taylor in Jeong et al., 2014: 219.

Daphnia sp. nov., clade L in Kotov & Taylor, 2019: figs 1, 2.

Etymology: The taxon is named for Korea, where this species was found; originally from Korean 고려, Koryŏ.

Type locality: A pond in Deok Seong (wetland) (36.51391°N, 127. 2669°E), Chuncheongnam-do, South Korea. The type series was collected on 17 September 2011 by H. G. Jeong and A. A. Kotov .

Holotype: An adult male, NIBRIV0000835125 .

A l l o t y p e: A p a r t h e n o g e n e t i c f e m a l e, NIBRIV0000835126.

Paratypes: Twenty parthenogenetic females, NIBRIV0000835127 . Twenty adult males, NIBR NIBRIV0000835128 . Twenty parthenogenetic females, NIBRIV0000835129 . Ten parthenogenetic females, MGU Ml181. The rest of the females and males, AAK M-2098 .

Other material excluded from type series (other date of collection): Many parthenogenetic females from type locality collected on 4 April 2012 by H. G. Jeong, A. A. Kotov, M. A. Gololobova and M. A. Kotova.

Short diagnosis: Parthenogenetic female. Body subovoid; caudal spine of moderate length ( Fig. 9A). Head relatively large, with a low anterior crest; head posterior margin with a strong, arched projection, with a deep incision between antenna I and labrum base ( Fig. 9B–D). Rostrum relatively short (as a result, tips of longest aesthetascs almost reach its tip); rostrum tip slightly bent posteriorly and subdividing into two lobes by a ‘line’ of prerostral fold, with posterior lobe always larger than anterior one. Spinules occupy less than half of dorsal and ventral valve margin. In posteroventral portion of valve, on inner face of valve, there are fine setae with setules between them ( Fig. 9E–I); no setules near caudal spine base ( Fig. 9J, K). First abdominal process almost straight, directed anteriorly ( Fig. 9L); second process short, bent distally; third process as a massive mound on the segment. Postabdomen with a smooth postanal angle. Postabdominal claw with first pecten: first (proximal-most) consisting of relatively short, rough teeth; second pecten consisting of seven or eight large teeth; third pecten consisting of numerous, fine setules ( Fig. 9L–N). Body of antenna I completely reduced; antennular seta arising immediately from head surface; aesthetascs protruding posteroventrally, with their tips almost reaching tip of rostrum ( Fig. 9D). Antenna as in previous species ( Fig. 10A–E). Limb I with a relatively long seta 3 ( Fig. 11A); limb II with an anterior seta 1 about two-thirds of the length of other setae, bilaterally setulated distally and 11–12 setae of filter plate of gnathobase ( Fig. 11D); limb III with seta 2 of exopod longer than seta 4, bearing short setules ( Fig. 11C); seta 3 on inner distal portion of limb of a moderate size ( Fig. 11D, E); limb IV ( Fig. 11F) as in previous species; limb V ( Fig. 11G) as in previous species.

Juvenile female I ( Fig. 10G, H) with a single necktooth.

Ephippial female with straight dorsal margin of valves; ephippium with two resting eggs, axes of which are perpendicular to its dorsal margin; egg chambers not separated from each other; posterodorsal portion of valves with caudal spine incorporated into ephippium ( Fig. 10I, J).

Adult male with dorsal margin of valves straight, not elevated above head; depression between head and valves shallow ( Fig. 12A); head with a welldeveloped rostrum ( Fig. 12B, C), without a supraoccular depression. Setulation of ventral margin and denticles on valves as in previous species ( Fig. 12D– J). Both setae and series of setules on inner face of posterior margin ( Fig. 12G). Abdomen first and second processes with smooth mounds; postabdomen with maximum height in its middle; postanal angle not expressed ( Fig. 12K, L). Gonopore opens subdistally, without a genital papilla. Postabdominal claw as in female ( Fig. 12 M-N). Antenna I with a small antennular seta, located far from distal end of antenna I body; male seta (flagellum) long, with its distal segment naked, slightly bent ( Fig. 12K). Limb I with ODL bearing a rudimentary seta and a large seta ( Fig. 13A) supplied with minute setules distally ( Fig. 13B); copulatory hook thick, with a tooth at tip ( Fig. 13C, D). Limb II distal-most endite with a short, hook-like anterior seta 1, with setulated distal segment ( Fig. 13E, F). Juvenile male ( Fig. 13G–I) with a necktooth.