Disparalona chappuisi (Brehm, 1931)

Lee, Sue Yeon, Yoo, Jung Sun & Kim, Seung Tae, 2017, Recent progress in studies of the Cladocera (Crustacea: Branchiopoda) of South Korea with seven new records for the Korean Peninsula, Journal of Species Research 6, pp. 227-246 : 230-232

2. Disparalona chappuisi (Brehm, 1931) ( Fig. 2)

Material deposited to NIBR. 5 parthenogenetic females from Chuksan Reservoir (N 35.9951°, E 126.8532°), Jeollabuk-do, coll. 31 Oct 2012 by H.G. Jeong , NIBR IV0000812486 .

Other localities. A reservoir beside Dongburo (N 35.1568°, E 128.1368°), Gyeongsangnam-do, coll. 29 Oct 2013 by H.G. Jeong; Ju Namji, Reservoir for agricultural water (N 35.3130°, E 128.6686°), Gyeongsangnam-do, coll. 10 Apr 2010 by H.G. Jeong; Dae Pyeon wetland (N 35.3393°, E 128.3388°), Gyeongsangnam-do, coll. 15 May 2010 by H.G. Jeong; Seon You Dong (N 35.3818°, E 127.9719°), Gyeongsangnam-do, coll. Sept 2011 by A.A. Kotov and H.G. Jeong; Cheok Ji Ri (N 35.4029°, E 127.9505°), Gyeongsangnam-do, coll. Sept 2011 by A.A. Kotov and H.G. Jeong; a pond Bak Sil Ji 3 (N 35.5384°, E 128.1262°), Gyeongsangnam-do, coll. 15 Sept 2011 by A.A. Kotov and H.G. Jeong; Bak Sil Ji 1 (large lake in wetland) (N 35.5418°, E 128.1209°), Gyeongsangnam-do, coll. 16 May 2010 by H.G. Jeong; Si Mock Ri (N 35.6076°, E 127.7756°), Gyeongsangnam-do, coll. Sept 2011 by A.A. Kotov and H.G. Jeong; A small puddle near Gu-Ryong waterfall (N 35.3946°, E 127.4836°), Jeollabuk-do, coll. 03 Apr 2012 by A.A. Kotov and H.G. Jeong; Chisan Reservoir (N 35.9953°, E 126.8511°), Jeollabuk-do, coll. 31 Oct 2012 by H.G. Jeong; Susi Reservoir (N 35.99848°, E 126.8703°), Jeollabuk-do, coll. 31 Oct 2012 by H.G. Jeong; Ho Tan, Back marsh connected with Geom river (N 36.1273°, E 127.6418°), Chungcheongbuk-do, coll. Sept 2011 by A.A. Kotov and H.G. Jeong; Nu Gyo Ri reservoir (N 36.1679°, E 127.6262°), Chungcheongbuk-do, coll. Sept 2011 by A.A. Kotov and H.G. Jeong; Sedongi Reservoir (N 36.3172°, E 127.2643°), Chungcheongbuk-do, coll. 31 Oct 2012 by H.G. Jeong; Seosang Reservoir (N 37.9276°, E 127.6997°), Gangwon-do, coll. 06 Sept 2012 by H.G. Jeong; Yunogol Reservoir (N 38.0628°, E 128.0027°), Gangwon-do, coll. 05 Sept 2012 by H.G. Jeong; Jeongiho Lake (N 38.2281°, E128.5644°), Gangwon-do, coll. 07 May 2016 by I. Karanovic and T. Karanovic .

Parthenogenetic female. Body regularly ovoid ( Fig. 2A), moderately compressed laterally, without any lateral projections, median dorsal keel absent ( Fig. 2B). Dorsal margin regularly curved, postero-dorsal angle rounded, posterior margin convex ( Fig. 2A). Sculpture of valves and head strongly developed: surface of valve in its postero-ventral and antero-ventral portions covered by long parallel sometimes anastomosing lines, between them short sometimes wavy lines, central portion of valves and head with short lines only. Valve ventral margin with setae of different length in different valve portion ( Fig. 2 C-E). Posteroventral angle of valve without denticles. Posterior margin of valve bears a row of numerous fine setules located quite close to the edge of its margin. Head with a long rostrum (distance between center of eye and ocellus two-three times shorter than distance between center of ocellus and tip of rostrum), compound eye and ocellus small ( Fig. 2A, F). Two major head pores, lateral head pores minute, located slightly asymmetrically to midline, closer to anterior major pore than to posterior one ( Fig. 2G). Labral keel relatively large, distal angle acute, with drawn tip ( Fig. 2H). Postabdomen subrectangular, relatively long (postanal margin in two times longer than anal margin), preanal and postanal angles well defined, distal angle of postabdomen almost right ( Fig. 2I). Postanal margin is armed by composite postanal denticles, decreasing in size proximally, anal margin with bunches of fine setules. Also, bunches of fine short setules present on lateral surfaces of these margins. Postabdominal claw long, subequal in length to anal margin, with two basal spines unequal in size ( Fig. 2I). Antenna I short, antennular sensory subequal in length to antennular body, arising at about 1/3 of way from tip, largest aesthetasc longer than half length of appendage ( Fig. 2J). Antenna II short, with a very small spine on proximal exopod segment, ( Fig. 2K). Antennal formula: setae 0-0-3/1-1-3, spines 1-0-1/0-0-1. The number of setae on thoracic limb I as for genus, inner distal lobe with first seta short, setulated in distal portion, second seta long, armed distally with short, fine setules, and long third seta represented by thick hook ( Fig. 2L). Length in our material 0.5-0.6 mm.

Notes. Yoon (2000) and Jeong et al. (2013) noted that the most common species from the genus Disparalona Fryer in Korea is D. hamata (Birge) (it was recorded by Yoon as Pleuroxus hamulatus ). But we found (unpublished data) that D. hamata is present in the New World only, while African and Asian tropics are populated by D. chappuisi (Brehm, 1931) . The latter differs from hamata mainly by a large labral keel (which is very small in the latter). All studied Korean populations belong to D. chappuisi .

This is a new record for the Korean Peninsula. This taxon should be regarded as a member of the southern thermophilic complex sensu Kotov (2016).