Pseudocandona Three new species of non-marine ostracods (Crustacea, Ostracoda) from small water bodies of northern China Yu, Na Ma, Shunxin Wang, Qianwei Zhai, Dayou ZooKeys 2022 2022-04-29 1097 183 207 http://zoobank.org/1023A7A8-5811-4B6E-8E8A-062596F1BA7B Yu & Ma & Wang & Zhai, 2022 Yu & Ma & Wang & Zhai 2022 Ostracoda Candonidae Pseudocandona CoL Animalia Pseudocandona cheni Podocopida 0 183 Arthropoda species cheni sp. nov.   Figs 1 , 2 , 3   Pseudocandonasp. 2 - Zhai et al. 2017: 486, fig. 9.  Type locality. A small shallow pond (Y26, Table 1) in Inner Mongolia, China.  Type material.  Holotype: one male (dyzoc567). Allotype: one female (dyzoc569). Paratypes: one male (dyzoc568) and three females (dyzoc570, dyzoc706, dyzoc707). All from the type locality, with soft parts dissected, valves preserved on the micropalaeontological slides.  Other material. One male (dyzoc625) and one female(dyzoc626), both from the site Y30 (Table 1), with soft parts dissected, valves preserved on the micropalaeontological slides. One female (dyzoc813), from the typelocality. One female (dyzoc814), from the site Y30 (Table 1). Both undissected, with carapace enclosed, preserved on the micropalaeontological slides.  Etymology. This species is named after Prof. Shouzhong Chen (= Shoutsung Chen; Institute of Hydrobiology, Chinese Academy of Sciences), who was the first among the Chinese ostracod workers to describe soft parts of non-marine ostracods from China ( Chen 1957).  Dimensions. Male, n= 3, LV, length 860-872 μm, height 510-535 μm; RV, length 842-849 μm, height 485-513 μm. Female, LV, n= 5, length 874-941 μm, height 526-574 μm; RV, n= 3, length 874-903 μm, height 497-520 μm.  Diagnosis. Carapace sub-trapezoidal in lateral view, relatively short and stout, with hinged part of dorsal margin nearly straight and sloping anteriorly (Fig. 1). Setal group on second segment of Md palp with five setae (Fig. 2D). Right palp of L5 with wide trunk and ventrally curved finger-like end (Fig. 3C). Left palp with elongated and ventrally curved trunk (Fig. 3D). Hemipenis with M-process triangular distally. Lobe atongue-like. Lobe bshortest, with sub-quadrate distal part on inner edge and triangular distal part on outer edge. Lobe hwith rounded distal part (Fig. 3G).  Description. Carapace surface densely covered with small shallow pits in anterior, posterior, and dorsal areas (Fig. 1B). In lateral view, greatest height posterior of mid-length. Postero-dorsal angle of male valve (Fig. 1A, B) slightly blunter than female (Fig. 1E, F). Ventral margin nearly straight. Anterior margin narrower than posterior. Anterior calcified inner lamella wide. Carapace compressed in anterior area and postero-ventral corner (Fig. 1I, J). LV overlaps RV on dorsal, ventral, and posterior sides, and slightly exceeds RV anteriorly (Fig. 1I, J).   Figure 1.  Pseudocandona chenisp. nov. A-Dmale, dyzoc567 (holotype) Aouter view of LV Bouter view of RV Cinner view of LV Dinner view of RV E-Hfemale, dyzoc569 (allotype) Eouter view of LV Fouter view of RV Ginner view of LV Hinner view of RV Ifemale, dyzoc813, dorsal view of carapace, anterior to left Jfemale, dyzoc814, ventral view of carapace, anterior to left. Scale bars: 100 μm. A1 (Fig. 2A) seven-segmented. First segment with two dorsal and two long ventral setae. Second segment with one short dorso-apical seta. Third segment without seta. Fourth and fifth segments with two long dorso-apical setae and one short ventro-apical seta, respectively. Sixth segment with one short and three long apical setae. Terminal segment with one short and two long setae and aesthetasc ya.   Figure 2.  Pseudocandona chenisp. nov. Amale, dyzoc567 (holotype), A1 Bmale, dyzoc567, A2 Cfemale, dyzoc570, part of A2 Dmale, dyzoc567, Md. Scale bars: 100 μm. Male A2 (Fig. 2B) five-segmented. Seta t2and t3transformed into male bristles, both similar in morphology, each terminating with slightly inflated, triangular process. Claws z1and z2long, slightly shorter than claw G2. Seta G3slim, slightly exceeding end of terminal segment. Claw G1short, slightly exceeding half-length of claw G2. Claw Gmslightly exceeding half-length of claw GM. Female A2 (Fig. 2C) four-segmented. Claw G2short, not reaching half-length of claw G3. Claw G3slightly shorter than claw G1. Claw Gmexceeding half-length of claw GM. Setae t1- 4unequally long, with t1and t3being longest while t4being shortest. Seta z1short, extending to ca. mid-way of terminal segment. Setae z2and z3extending to ca. mid-way of G-claws but z2slightly longer than z3. Md (Fig. 2D) palp with short and slender  α-seta. Seta  βshort and slender with 5 grouped setae and one sub-equally long accompanying seta on second segment. Seta  γlong, smooth, and slender. Mx (Fig. 3A) palp two-segmented. Second segment spatulate. Two tooth-bristles on third masticatory lobe smooth. Male L5 (Fig. 3C, D) asymmetrical. Right palp basally wide, grading to finger-like end, with two sub-apical setae. Left palp distally narrower than right, with two sub-apical setae.   Figure 3.  Pseudocandona chenisp. nov. Amale, dyzoc567 (holotype), Mx Bfemale, dyzoc570, L5 Cmale, dyzoc567, right L5 palp Dmale, dyzoc567, left L5 palp Emale, dyzoc567, L6 Fmale, dyzoc567, L7 Gmale, dyzoc567, Hp Hmale, dyz567, UR. Scale bars: 100 μm. Female L5 (Fig. 3B) with long b- and d- setae, and one long a-seta. L6 (Fig. 3E) five-segmented. First segment with d1-seta extending slightly beyond this segment. Setae eand fextending to ca. tips of second and third endopodal segments, respectively. Seta gexceeding beyond terminal segment with ~ 50% of length. Terminal segment with h1-seta conspicuously longer than h3-seta. L7 (Fig. 3F) five-segmented. First segment with d1-, d2- and dp- setae. Setae eand fabsent. Seta glong. Terminal segment with short h1-seta and long h2- and h3- setae. UR (Fig. 3H) with tiny seta Sa.Claw Gpslightly shorter than claw Ga.Seta Spslightly exceeding end of ramus. Hemipenis (Fig. 3G) sub-ovate in outline. Lobe atongue-like, with sub-quadrate distal end. M-process with triangular distal part. Lobe bshorter than lobes aand h, with sub-quadrate distal part on inner edge and triangular distal part on outer edge. Lobe hslightly shorter than lobe a, with rounded distal part. Bursa copulatrix elongated with long finger distally.  Remarks. The genus  PseudocandonaKaufmann, 1900, with 72 species described to date, is the third most diverse genus of the non-marine ostracods after  CandonaBaird, 1845 and  StrandesiaStuhlmann, 1888 (see Meisch et al. 2019). [ Karanovic (2005, 2012) proposed an alternative taxonomic scheme where Typhlocypris Pseudocandonais treated as a subgenus under the genus Typhlocypris Vejdovsky, 1882 and it only contains the six species of the  Pseudocandona compressagroup, but we follow Namiotko et al. (2014)who redefined the genus  Typhlocypris.] The genus, as accepted at the moment, consists of five species groups ( caribbeana,  Pseudocandona compressa, prespica, rostrata, and zschokkei) and some species with uncertain positions ( Namiotko and Danielopol 2004; Meisch et al. 2019). This division is mostly based on the number of posterior setae on the second segment of Md palp. Species with 5+1+  βsetae, as well as with the h1-seta on the L7 being more than twice the length of terminal segment, are classified in the  Pseudocandona compressagroup ( Meisch 1996, 2000; Namiotko and Danielopol 2004), to which the present new species also belongs. Other species of this group are  P. albicans(Brady, 1864),  P. compressa(Koch, 1838),  P. insculpta(G. W. Mueller, 1900),  P. pratensis(Hartwig, 1901),  P. regisnikolaiKaranovic & Petkovski, 1999, and  P. sucki(Hartwig, 1901) ( Karanovic and Petkovski 1999; Meisch 2000; Karanovic 2012).  Pseudocandona albicanscan be distinguished from the present species by a shorter seta that accompanies the group of the five setae on the Md palp (sub-equally long to the grouped setae in the present species), a much slenderer first endopodal segment of the L6, as well as a slenderer carapace in dorsal view ( Meisch 2000). Male bristles on the A2 are absent in  P. insculpta( Meisch 2000), which easily distinguishes it from the present species. No other species of the  Pseudocandona compressagroup has the morphology of the male L5 and the Hp similar to  P. cheni. In  P. compressa,  P. insculpta, and  P. pratensis, the lob his not distally inflated (albeit slightly curved in  P. pratensis), their right L5 have slenderer trunks. The lobe hin  P. suckiis very wide, while the lobe bis small ( Meisch 2000).  Pseudocandona regisnikolaiis much larger (females range between 1.33 and 1.4 mm and males are up to 1.53 mm) ( Karanovic and Petkovski 1999). In addition,  P. regisnikolaipossesses only one dorsal seta on the basal segment of the A1, setae t2and t3on the male A2 are not transformed into bristles, the left prehensile palp of male is much slenderer than the right one, and the Hpbears a conspicuous lobe g( Karanovic and Petkovski 1999).