Investigation of the distribution patterns in moinids (Crustacea: Cladocera: Moinidae) forming ephippia with two resting eggs Author Neretina, Anna N. A. N. Severtsov Institute of Ecology and Evolution, Leninsky Prospect 33, Moscow 119071, Russia. Author Alonso, Miguel FEHM-Lab (Freshwater Ecology, Hydrology and Management), Ecology Section, Department of Evolutionary Biology, Ecology and Environmental Sciences, Faculty of Biology, University of Barcelona, Avda. Diagonal 643, 08028 Barcelona, Spain. Author Kotov, Alexey A. A. N. Severtsov Institute of Ecology and Evolution, Leninsky Prospect 33, Moscow 119071, Russia. text Zootaxa 2024 2024-09-23 5512 4 451 490 http://dx.doi.org/10.11646/zootaxa.5512.4.1 journal article 10.11646/zootaxa.5512.4.1 1175-5326 13849048 F5ED84F2-3166-4B85-B3F7-22EBDD84F726 Moina kaszabi Forró, 1988 ( Figs. 11–15 , 16C–D , 22C ) Moina cf. belli .— Brtek et al. 1984 : p. 98 , figs. 42–48. Moina kaszabi Forró, 1988 : p. 203 –207, figs. 1–12. Etymology. This species was named in the honor of Dr Zoltán Kaszab, who collected the material of this species in Mongolia . Type locality. “Čojbalsan aimak, Fluss Kerulen bei Čojbalsan, 700 m , 16 August 1965 .—Vom stehenden Salzwasser neben der Brücke mit Wassernetz gefangen” ( Forró 1988 ), Dornod Aimag , Mongolia . Type material. The whole type series is stored at the Hungarian Natural History Museum ( Budapest , Hungary ) ( Forró 1988 ) . Other material examined. Mongolia : 40 parthenogenetic females, 20 ephippial females, 20 males from Buur nuur, Sukhbaatar ( N 45.40467° , E 112.99678° ), coll. 31.08.2006 by M. Alonso , AAK 2017-016; from Delgereh sumiin toirom 2, Dorngovi ( N 45.65025° , E 110.92867° ), coll. 30.08.2006 by M. Alonso , MA 1069DOG; from Buur nuur, Sukhbaatar ( N 45.40467° , E 112.99678° ), coll. 31.08.2006 by M. Alonso , MA 570 SU . Russia : 2 parthenogenetic females from the pool 2 in the vicinities of Novo-Il’inskoe village ( N 52.48021° , E 116.7808° ), Zabaikalsky Territory , coll. in August of 2018 by A.A. Kotov , D.P. Karabanov , A.A. Zharov & M.A. Gololobova , AAK M30-024b; 5 parthenogenetic females from the roadside pool ( N 50.00466° , E 115.7153° ), the Daursky Nature Reserve , Zabaikalsky Territory , coll. 11.08.2018 by D.P. Karabanov , A.A. Zharov & A.A. Kotov , AAK M-4690; 10 parthenogenetic females, 5 ephippial females, 5 males from acow drinking pool (the remainder of Zun Torey Lake ) ( N 50.06133° , E 115.6647° ), the Daursky Nature Reserve , Zabaikalsky Territory , coll. 11.08.2018 by D.P. Karabanov , A.A. Zharov & A.A. Kotov , AAK M-4691; 1 parthenogenetic females from a pool with Juncus sp. ( N 50.02935° , E 116.8831° ), Semiozerye , Zabaikalsky Territory , coll. 16.08.2018 by D.P. Karabanov , A.A. Zharov & A.A. Kotov , AAK M-4721; 5 parthenogenetic females from the roadside pool ( N 50.03054° , E 116.8851° ), Semiozerye , Zabaikalsky Territory , coll. 16.08.2018 by D.P. Karabanov , A.A. Zharov & A.A. Kotov , AAK M-4722 . Short diagnosis. Adults of a large size for genus (length of adult parthenogenetic female to 1.35 mm ). Parthenogenetic female with body shape typical of genus. Surface of head and valves with fine setae. Head relatively large, without rostrum, with dorsal head pore. Ocellus absent. Inner side of valve with setulae after ventralmost setae prominently grouped. Preanal margin of postabdomen covered by rows of relatively long hairs. Distalmost tooth on postabdomen bident. Base of postabdominal claw with first pecten containing denticles somewhat larger than following denticles. Antenna I relatively thick. Antenna II and thoracic limbs as for genus. Anterior stiff setae 1 and 2 of thoracic limb I armed by fine densely located short setules. Ephippium brownish, containing two resting eggs. Its dorsal part with microsculpture represented by transverse wrinkles. In lateral view, macrosculpture of ephippium central portion as polygonal meshes. Male with elongated body, head and valves covered by fine hairs. Gonopore opening on dorsolateral position at some distance from base of postabdominal claw. Antenna I long, terminally with 6–7 thick bisegmented hooks of similar size. Thoracic limb I with a long exopodite. Redescription. Parthenogenetic female. General . Body brownish, ovoid in lateral view, shape typical of the genus (body height/length ratio is about 0.62 for adults, varying significantly due to extension of brood chamber development), maximum height in middle ( Fig. 11A ). Dorsal margin of valve elevated above head level. Posterodorsal angle of carapace expressed, usually acute. Posteroventral angle broadly rounded. Ventral margin of valve rounded, anterodorsal angle rounded. Sculpture of valves fine, represented by cells elongated in dorsoventral direction. Superficial hairs on head and valves surface. In dorsal and ventral view, body subovoid, laterally compressed in anterior view. FIGURE 11 . Moina kaszabi Forró, 1988 , adult parthenogenetic female from Sukhbaatar, Mongolia. A, Adult parthenogenetic female, general view. B, Head, lateral view. C, Labrum. D, Valve. E, Setulated hooks on posterior most portions of valves. F, Armature of posterior margin of valve. G, Armature of posteroventral portion of valve. H, Armature of ventral portion of valve. I–K, Postabdomen. L–M, Postabdominal claw in outer and inner views. Scale bars 0.1 mm. FIGURE 12 . Moina kaszabi Forró, 1988 , adult parthenogenetic female from Sukhbaatar, Mongolia.A, Antenna I. B–C, Antenna II. D, Limb I. E, Limb II. F–G, Gnathobase of limb II and its setae. H, Limb III. I, Innerdistal portion of limb III. J, Limb IV. K, Innerdistal portion of limb IV. L, Limb V. Scale bars 0.1 mm. FIGURE 13 . Moina kaszabi Forró, 1988 from Sukhbaatar, Mongolia. A–F, Ephippial female. G–S, Adult male. A, Ephippial female, general view. B, Ephippium, lateral view. C–D, Ephippium dorsal plate. E–F, Ornamentation of central portion of ephippium. G, Adult male, general view. H, Labrum. I, Valve. J, Setulated hooks on posterior most portions of valves. K, Armature of posteroventral portion of valve. L, Armature of ventral portion of valve. M–N, Postabdomen. O, Antenna I. P, Distal portion of antenna I. Q–S, Limb I and its portions. Scale bars 0.1 mm. FIGURE 14 . Moina kaszabi Forró, 1988 , adult parthenogenetic female from Sukhbaatar, Mongolia. A, Dorsal head pore. B, Valve. C, Setulated hook on posterior most portion of valves. D, Armature of ventral portion of valve. E, Armature of posteroventral portion of valve. F–G, Postabdomen and its distal portion. H, Preanal portion of postabdomen. I, Postabdominal claw, outer view. J, Limb I. Scale bars 0.1 mm for F, 0.05 mm for B, G–H, J, 0.02 mm for A, C–E, I. FIGURE 15 . Moina kaszabi Forró, 1988 from Sukhbaatar, Mongolia. A–E, Ephippial female. F–G, Adult male. A, Antenna II. B, Ephippium, lateral view. C–D, Ornamentation of ephippium. E, Ephippium dorsal plate. F–G, Male postabdomen and its distal portion. Scale bars 0.2 mm for B, 0.1 mm for A, C–D, F, 0.02 mm for E, G. FIGURE 16 . Comparison of armature of posteroventral portion of valve in Moina belli Gurney, 1904 from Pool 2 on Thaba Tseka Road, km 45.2 from T.O., Drakensberg, Lesotho (A–B) and Moina kaszabi Forró, 1988 from Sukhbaatar, Mongolia (C–D). A, C, Posteroventral portion of valves, outer view. B, D, Posteroventral portion of valves, inner view. Scale bars 0.05 mm for –D, 0.02 mm for A, 0.01 mm for B. Head typical of genus, relatively large, with shallow supra-ocular depression ( Fig. 11B ). Compound eye large, ocellus absent. Ovoid dorsal head pore on anterior side of depression between head and brood chamber. Labrum “ Ilyocryptus -like” (sensu Hudec 2010 ) ( Fig. 11C ), similar to that of M. belli . Valve large, ovoid. Anterior portion of ventral margin with relatively long setae, covered by short setulae ( Fig. 11D, G, H ). Inner side of valve, setulae after ventralmost setae prominently grouped; distalmost setula in each group longer and thicker than setulae located more proximally to setulated setae ( Fig. 11G ). Posteroventral portion of valve with setulae subequal in size and thickness ( Fig. 11F ). Setulated curved hooks in the dorsalmost portion of valve posterior margin ( Fig. 11E ). Thorax relatively long, abdomen short, proportions typical for genus. Postabdomen elongated, with conically narrowing distal portion ( Fig. 11I–K ), proportions and armature similar to that of M. belli . Preanal margin with transverse rows of long hairs. Anal margin covered by bunches of short setulae. Basis of claws not inflated. On lateral face, postanal margin with large bidentate tooth (branches always unequal in length) and row of 7–9 large, triangular plumose teeth. Postabdominal seta almost two times longer than postabdomen; its distal segment covered by long delicate setulae. Postabdominal claw large, slightly curved, with pointed tip ( Fig. 11L–M ), proportions and armature as in M. belli . Antenna I rod-like, elongated (its length approximately six diameters of antennular body base), slightly curved ( Figs. 11B , 12A ), as in M. belli . Antenna II large ( Fig. 12B–C ), as in M. belli . Antennal formula: setae 0-0-1-3/1-1-3, spines 0-1-0-1/0-0-1. Lateral and apical swimming setae of both antennal branches covered by long, fine setulae. Spine on second exopod segment short but comparable in length with both apical exopod and endopod spines. Mandible and maxilla I not studied. Thoracic limbs : five pairs ( Fig. 12D–L ), proportions and armature as in M. belli . Ephippial female . Characters of ephippial female similar to those of parthenogenetic female except dorsal portion of valves modified into a dark brown ephippium, containing two resting eggs ( Fig. 13A ). Dorsal part of valves with wrinkled, chitinous reinforced, dorsal plate ( Fig. 13B ); microsculpture of plate represented by transverse wrinkles ( Fig. 13C, D ). In lateral view, macrosculpture of ephippium central portion represented by polygonal meshes ( Fig. 13E ). Surface of some cells in central portion wrinkled ( Fig. 13F ). Ornamentation of anterior portion of ephippium represented by rectangular cells, not protruding above ephippium surface. Male. In lateral view ( Fig. 13G ), body ovoid, slightly elongated as compared to female (body height/length about 0.50). Dorsal margin of valve slightly elevated above head, posteroventral angle distinct. Head more elongated than in female, also covered by fine hairs. Labrum similar to that of female ( Fig. 13H ). Dorsal head pore present. Compound eye large, ocellus absent ( Fig. 13G ). Valve ovoid, more elongated than in female; anterior surface also covered by fine hairs. Armature of ventral margin ( Fig. 13I, K–L ) of valve as in female. Setulated curved hooks ( Fig. 13J ) located in dorsalmost portion of posterior margin of valve. Thorax relatively long, abdomen short. Postabdomen generally as in female, with preanal margin covered by transverse rows of long hairs ( Fig. 13M– N ). Gonopore opening on dorsolateral position at some distance from base of postabdominal claw. Antenna I significantly longer than in female, curved, covered by tiny hairs and transverse rows of minute denticles ( Fig. 13O ). Antennular sensory seta long, arising from proximal quarter of antennular body. Male seta more robust, located at some distance from sensory seta. Apical tip of antennular body separated into two parts: first part with nine short aesthetascs, second part with 6–7 thick bisegmented hooks of similar size ( Fig. 13P ). Limb I ( Fig. 13Q ) generally as in female, but with large, curved copulatory hook ( Fig. 13R ) and long exopodite. Proximal portion of exopodite covered by long setulae, distal portions with small denticles ( Fig. 13S ). Size. Adult parthenogenetic females to 1.35 mm ; ephippial females to 1.00 mm; adult males to 0.95 mm . Variability. No significant variability was found between all investigated individuals ( Figs. 14–16 ). Taxonomic remarks. In the paper of Kotov et al. (2013) , the name of M. kaszabi was misspelt as Moina kazsabi Forró, 1988 . We cannot exclude that M. kaszabi is a junior synonym of M. turkomanica due to “a relatively small” geographical distance between the Karakum Desert and Mongolia and similarities of the environmental conditions at the respective type localities of the two taxa. Populations from the Karakum Desert should be re-examined in the future. Unfortunately, original Keiser’s materials are lost (see above). Moina gouldeni Mirabdullaev, 1993 from Kazakhstan and Uzbekistan according to description of Mirabdullaev (1993) could belong to M. belli species due to its large size (length of parthenogenetic female to 1.47 mm ), bristled seta 2 of limb I, two eggs in the ephippium and long exopodite in male limb I. Armature of ventral margin and posteroventral portion of valve in this taxon is represented by a row of fine ungrouped denticles after the posteriormost seta ( Mirabdullaev 1993 ).This character shares M. gouldeni with M. belli s.str. , rather than with M. kazsabi . But then Mirabdullaev et al. (2009) considered this taxon as a junior synonym of M. lipini Smirnov, 1976 , although the first description of the latter included only a very superficial morphological analysis, Bekker et al. (2016) revealed (based on genetic methods) that there is only a sole M. lipini clade in Central and Southern portions of European Russia (i.e. at the border of Kazakhstan ). Unfortunately, no information about dorsal dorsal head pore was represented by Mirabdullaev et al. (1993 , 2009). Note that according to these authors, specimens identified at first as M. gouldeni and then as M. lipini have no hairs on their heads and valves. This character shares M. gouldeni and M. lipini with M. ephemeralis Hudec, 1997 . Therefore, M. ephemeralis may also be a junior synonym of M. lipini . The same idea was already proposed by Bekker et al. (2016) . Interestingly, Hudec (1997) said nothing about a head pore in M. ephemeralis . The presence of short hairs on preanal margin of postabdomen again shares M. ephemeralis with M. lipini and M. gouldeni . Apparently, it is a very dubious step to separate a special subgenus Exomoina Hudec, 2010 for M. ephemeralis and M. macrocopa . Although these two species have two eggs in the ephippium and long exopodite in male limb I, they significantly differ from each other by several small-scale, but important, morphological features. Moreover, we have to date a more promising set of morphological traits in the large-size tropical and subtropical moinids as compared to that used by Hudec (2010) : presence of two eggs in the ephippium, different length of hairs on dorsal side of postabdomen, lack of head pore and presence/or absence of long exopodite on male limb I ( Goulden 1968 ; Smirnov 1976 ; Martínez-Jerónimo et al. 2004 ; Neretina & Kirdyasheva 2019 ). The genetic distance between the M. macrocopa -clades and M. lipini is also quite large, although they are grouped together ( Bekker et al. 2016 ). No doubt, the fine morphology of moinids with two eggs in the ephippium from Central Asia should be re-examined in the future in order to clarify their taxonomic status. However, to date it is evident that diversity of moinids in the arid regions of Palearctic is underestimated and separation of the subgenus Exomoina based only on European species is premature. Distribution and ecology. Several populations of M. kaszabi are known from Mongolia ( Brtek et al. 1984 ; Forró 1988 ; our study) and from steppes of Asian Russia at the border with Mongolia (our study), but they are not recorded in the Great Lake Depression ( Alonso et al . 2019b ) and large saline lakes of Mongolia ( Alonso 2010 ). Any belli -like populations are unknown also from China ( Xiang et al . 2015 ; Ni et al. 2019 ) and Japan ( Makino et al. 2020 ). Ecologically, M. kaszabi is similar to M. belli and also inhabits temporary water bodies with muddy, sometimes highly eutrophic, waters.