Pseudochydorus bopingi, Sinev, Artem Y., Garibian, Petr G. & Gu, Yangliang, 2016

Sinev, Artem Y., Garibian, Petr G. & Gu, Yangliang, 2016, A new species of Pseudochydorus Fryer, 1968 (Cladocera: Anomopoda: Chydoridae) from South-East Asia, Zootaxa 4079 (1), pp. 129-139 : 130-135

publication ID	https://doi.org/ 10.11646/zootaxa.4079.1.9
publication LSID	lsid:zoobank.org:pub:493A1823-7314-4028-8902-E77A256F8FA1
DOI	https://doi.org/10.5281/zenodo.5659862
persistent identifier	https://treatment.plazi.org/id/D35587C4-0460-FF90-E3D6-FAABFD5AF885
treatment provided by	Plazi
scientific name	Pseudochydorus bopingi
status	sp. nov.

Treatment

Pseudochydorus bopingi sp. nov.

( Figs. 1–4 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 )

Chiang & Du, 1979: fig. 186A–B ( globosus ); Sinev & Korovchinsky, 2013: 134, fig. 4J–K ( globosus ).

Etymology. Species name honors Professor Boping Han (Institute of Hydrobiology, Jinan University, Guangzhou), who initiated our cooperation program.

Type locality. Roadside pond in Hunan province, China (25°55.518'N; 112°36.455'E), collected the 12/04/ 2014 by A. Y. Sinev & Y. Gu.

Type material. Holotype. Parthenogenetic female from the type locality, ZMOU, Ml-147.

Paratypes. 6 parthenogenetic females from the type locality, ZMOU, Ml-147; 3 parthenogenetic females from a lake in Hunan province, China (26°52.317'N; 112°44.067'E), collected the 12/04/2014 by A. Y. Sinev & Y. Gu, AYS; 3 parthenogenetic females from small reservoir at Hainan Island, China (19°27.601'N; 110°03.267'E) collected the 21/04/2014, by A. Y. Sinev & Y. Gu, AYS.

Material examined. Six more females from the type locality were dissected for the analysis of appendages.

Description. Female. General. Body of preserved specimens intense yellow with brownish pigment spot at the middle of the valves. In lateral view body almost round ( Fig. 1 View FIGURE 1 A–B, 2A–B); height/length ratio about 0.9; maximum height at the middle of the body. Body globular, only weakly compressed laterally ( Fig. 2 View FIGURE 2 A–G).

Valves with broad flattened flange ( Fig. 2 View FIGURE 2 G, 3A) going from the middle of ventral margin to the posterodorsal corner. Anterior corner broadly rounded. Ventral margin ( Fig. 1 View FIGURE 1 C) with about 80 setae located on the inner side of valves. Postero-ventral corner without denticles. Valves, except posterovenrtal flange, covered by polygonal sculpture ( Fig. 3 View FIGURE 3 A–B), in ventral portion of valves each polygon bears one-two small depressions in ventral angles.

Head with moderately long rostrum, pointing down. Length of rostrum (measured from tip to the level of mandibular articulation point) about 0.33–0.39 height of the body. Diameter of ocellus 3 times smaller than diameter of eye. Distance between ocellus and tip of the rostrum is less than 1.5 distance between ocellus and center of the eye. Headshield ( Fig. 1 View FIGURE 1 D–G) large, with maximum width at the middle of posterior portion, its posteriormost portion wide oval. Rostrum with elongated blunt tip ( Fig. 1 View FIGURE 1 H, 3D). Headshield with polygonal sculpture, less pronounced than on valves. Head pores of typical for Chydorinae morphology ( Fig. 3 View FIGURE 3 C), PP about 3 IP. Labrum with reduced labral keel.

Postabdomen ( Fig. 1 View FIGURE 1 I–J, 2H) long and narrow in postanal portion with parallel margins, or weakly narrowing distally; maximum height at postanal angle. Length about 4–4.5 heights. Ventral margin straight. Basis of claws separated from distal margin by clear incision. Distal margin weakly convex, distal angle rounded. Dorsal margin almost straight in postanal portion, strongly concave in anal portion, concave in postanal portion. Distal (anal + postanal) part 2–2.5 times longer than the preanal portion. Postanal portion 1.5–1.8 times longer than anal portion. Preanal angle well expressed, prominent; postanal angle weakly defined. About 15 narrow sharp denticles at postanal margin decreasing in size basally, some of them with additional smaller denticles basally. Length of longest denticles little more than width of the postabdominal claw base. Postanal portion with 8–10 lateral fascicles of short setulae; distalmost fascicles consisting of 1–6 thick setulae only, in basal portion fascicles consist of more than 10 longer and thinner setulae. Postabdominal claw long, slender, curved, slightly longer than preanal portion of postabdomen; two basal spines, distal spine about 0.2 length of the claw, proximal spine 3 times shorter. A pecten of short spinulae on dorsal side of claw, in basal part spinulae thicker and spaced more sparsely than in distal one. A row of very thin short setulae along ventral margin of claw, these setulae can be observed only at high magnification.

Antennule ( Fig. 1 View FIGURE 1 K, 3E) large, slightly curved, length about 2 widths. Antennular seta short, about 1/3 length of antennule itself, arising at 1/2 distance from the base of antennule. Nine terminal aesthetascs, longest ones longer than antennule.

Antenna relatively short ( Fig. 1 View FIGURE 1 L–M, 3 E–F). Antennal formula: setae 0-0-3/1-1-3; spines 1-0-1/0-0-1. Basal segment robust, with very short seta between branches. Branches long and slender; in both branches basal segment 2 times longer and thicker than two others. Seta arising from basal segment as long as middle segment or shorter. Seta arising from middle segment of endopodite of similar size of apical setae. Apical setae of similar thickness and length. All spines very short.

Mandibules typical for the subfamily.

Maxillae ( Fig. 1 View FIGURE 1 N) with three slender setae armed with spinules, two shorter setae 3 times shorter than longest one.

Thoracic limbs: five pairs.

Limb I of moderate size ( Fig. 4 View FIGURE 4 A–C). Epipodite oval, without projection. ODL with two setae, one of them very small. IDL with three setae, a row of long setulae and a row of short thick spines. IDL seta 1 very thick, hooklike, about 1/2 length of longest ODL seta, with row of spines at the middle; seta 2 about 2/3 length of longest ODL seta; seta 3 little shorter than longest ODL seta; setae 2–3 armed with thick spines in distal part. Endite 3 with four setae subequal in length, seta “a” longer than other setae (1 and b–c). Endite 2 with three long distally setulated setae (d–f) and a naked inner seta (2) on anterior face of limb, seta “f” as long as longest ODL seta. Endite 1 with two setae of similar size (g–h) and a naked inner seta (3) on anterior face of limb. Five rows of thin long setulae on ventral face of limb. Two thin ejector hooks of similar size.

Limb II subtriangular ( Fig. 4 View FIGURE 4 D–E). Exopodite small, of irregular shape, exopodite seta very long, as long as scraping spine 2. Eight scraping spines; spines 1–3 long, decreasing in size basally, each armed with strong denticles. Spines 4–8 short, evenly decreasing in size basally; spine 4 armed with thick, densely spaced denticles; spines 5 and 8 with short setulae; spines 6–7 with long setulae. Two small setae or sensillae located between spines 3–4 and between spines 4–5. Distal armature of gnathobase with three elements. Filter plate II with five setae, two of them oriented toward scraping spines.

Limb III ( Fig. 4 View FIGURE 4 F–H). Epipodite oval, without finger-like projection. Exopodite narrow, rectangular, with three lateral (1–3) and four terminal (4–7) setae. All setae rather short, seta 4 being longest, only 1.5 times longer than exopodite itself. Seta 6 slightly shorter than seta 4; setae 5 and 7 of same length, about 2/3 length of seta 4; seta 1 about 1/2 length of seta 4; setae 2 and 3 very short. Setae 1–5 plumose; setae 6 unilaterally armed with long setulae in basal portion, seta 7 unilaterally armed with short setulae. Distal endite with three scraping setae (1–3), slender, sharp, with small denticles in distal part, decreasing in size basally; two small sensillae located between their bases. Basal endite with 4 setae (a–d) of similar size. Five pointed inner setae increasing in size basally; a small bottleshaped sensillum near the distalmost seta. Distal armature of gnathobase with three elements: a longer seta and two spines. Filter plate III with five setae, oriented in opposite directions.

Limb IV ( Fig. 4 View FIGURE 4 I–K). Pre-epipodite setulated; epipodite oval, without projection. Exopodite oval, with seven plumose setae; seta 1 being longest; length of setae decreases evenly from seta 1 to seta 6; seta 7 about 2/3 length of seta 6, and much thinner than other setae. Inner portion of limb IV with two setae; scraping seta (1) long and slender, seta 2 three times shorter than seta 1, setae 3–4 not found. Four inner setae (a–d) of similar size; setae a–b unilaterally armed with long setulae. Gnathobase with one 2-segmented setae and a sensilla. Filter plate IV with four setae.

Limb V ( Fig. 4 View FIGURE 4 L). Pre-epipodite setulated; epipodite oval, with short projection. Exopodite large, oval with protruding inner portion, with four rather short plumose setae of similar length. Inner lobe subtriangular with rounded apex, with several clusters of long setulae on inner margin. Inner face with two setae, distal seta 2 times shorter than basal one. Filter plate V with three setae.

Male and ephippial female unknown.

Size: length of adult female in studied material from 0.39 to 0.5 mm.

Differential diagnosis. P. bopingi differs from P. globosus by a smaller size, well-developed flattened flange along the posterior margin of valves, shorter rostrum, smaller ocellus, shorter seta on basal segment of antenna exopodite, and different armament of scrapers 5 and 8 of thoracic limb II as specified in Table 1 View TABLE 1 .

Distribution. P. bopingi is known from South Vietnam ( Sinev & Korovchinsky 2013) and South and East China—Hainan Island, Hunan and Hubei provinces.