Daphnia jejuana, 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 JEJUANA SP. NOV.

( FIGS 14–18)

LSID: urn:lsid:zoobank.org:act:35E53D06-8D20-4440-9227-69F52DE11D56

Daphnia sp. nov., clade K of Kotov & Taylor, 2019: figs 1, 2.

Etymology: The taxon is named after its type locality, Jeju Island ( Republic of Korea), from Korean ‖주도, Jeju-do.

Type locality: DoSun-cheon pool 1 (33.30593°N, 126.4672°N), Jeju-do, South Korea. The type series was collected on 28 November 2012 by A. A. Kotov and H. G. Jeong .

Holotype: An adult male, NIBRIV0000835132. 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, N I B R I V 0000835133.

Paratypes: Twenty adult males, NIBRIV0000835135. Twenty parthenogenetic females, NIBRIV0000835134. Ten parthenogenetic females, MGU Ml182. Five adult males, MGU Ml183. Many males, ephippial and parthenogenetic females, AAK M-2556 and AAK M-2557.

Material excluded from type series: many ephippial and parthogenetic females from pond near Dream Forest (33.48783°N, 126.6946°E), collected on 13 February 2012 by H. G. Jeong, AAK M-2353 and AAK M-2355; 20 females from the same locality, NIBRIV0000835130 ; many males, ephippial and parthenogenetic females from pond near Hallasan (33.43225°N, 126.5983°N), collected on 28 November 2012 by A. A. Kotov and H. G. Jeong, AAK M-2552; 20 females from the same locality, NIBRIV0000835131 ; many parthenogenetic females from pond in Dream forest (33.48719°N, 126.7031°E), collected on 28 November 2012 by A. A. Kotov and H. G. Jeong, AAK M-2553; many males, ephippial and parthenogenetic females from DoSun-cheon pool 2 (33.30595°N, 126.4658°E), collected on 28 November 2012 by A. A. Kotov and H. G. Jeong, AAK M-3280 and AAK M-3281; a few parthenogenetic females from Billbae pond (33.40374°N, 126.351°E), collected on 28 November 2012 by A. A. Kotov and H. G. Jeong, AAK M-3289; and 20 females from the same locality, NIBRIV0000835136 .

Short diagnosis: Parthenogenetic female. Body subovoid; caudal spine of moderate length ( Fig. 14A). Head relatively large, with a low anterior crest; head posterior margin with a strong, arched projection; a deep incision between antenna I and labrum base ( Fig. 14B–E). 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. 14F–K); no setules near caudal spine base ( Fig. 14L). First abdominal process almost straight, directed posteriorly ( Fig. 14M); second process short, bent distally; third process as a massive mound on the segment. In juveniles, abdominal segments rudimentary ( Fig. 14N). Postabdomen with a projected postanal angle ( Fig. 14M, N). Postabdominal claw with first pecten: first (proximal-most) consisting of relatively long, thin teeth; second pecten consisting of six to eight large teeth; third pecten consisting of numerous, fine setules ( Fig. 14O, P). Body of antenna I completely reduced; antennular seta arising immediately from head surface; aesthetascs protruding posteroventrally, and their tips reach tip of rostrum ( Fig. 14E). Antenna as in previous species ( Fig. 15A– G). Maxilla I as in previous species ( Fig. 16A). Limb I with a relatively long seta 3 ( Fig. 15B); limb II with an anterior seta 1 about two-thirds of the length of other setae, bilaterally setulated distally and numerous setae of filter plate of gnathobase ( Fig. 16C); limb III with seta 2 of exopod shorther than seta 4, bearing short setules ( Fig. 16D); seta 3 on inner distal portion of limb of a moderate size ( Fig. 16E); limb IV ( Fig. 16F) as in previous species, limb V ( Fig. 16G) as in previous species.

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. 15H, I).

Adult male with dorsal margin of valves straight, not elevated above head; depression between head and valves present ( Fig. 17A); head with a well-developed rostrum ( Fig. 17B–D), without a supra-occular depression. Setulation of ventral margin and denticles on valves as in previous species ( Fig. 17E–I). Only setae on inner face of posterior margin ( Fig. 17H, I). Abdomen first and second processes as smooth mounds; postabdomen with maximum height in its middle; postanal angle projected ( Fig. 17K, L). Gonopore opens subdistally, without a genital papilla. Postabdominal claw as in female ( Fig. 17M). 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. 17B–D, 18A, B). Limb I with ODL bearing a rudimentary seta and a large seta ( Fig. 18C) supplied with minute setules distally ( Fig. 18D); copulatory hook thin, with a tooth at tip ( Fig. 18E, F). Limb II distalmost endite with a short, hook-like anterior seta 1, with setulated distal segment ( Fig. 18G).