Pleuroxus pamirensis Werestschagin 1923

Pleuroxus pamirensis (Werestschagin, 1923) Figs 5–6 Cornuella pamirensis Werestschagin 1923: 33 -36 (in Russian), 39–40 (in German), Table 2: figs 13–20, Table 3: figs 21– 26; Rylov 1940: 338; Manujlova 1964: 244–245, fig. 129. Pleuroxus pamirensis (Werestschagin) in Smirnov 1971: 257, figs 259–261; Smirnov 1996: 67 –68 (only Pamirs). Not Pleuroxus pamirensis (Werestschagin) in Smirnov 1996: figs 252–253. Type series. Type locality. Lake Zorkul, East Pamirs, Tajikistan (altitude: 4138 m, 37 º 26 ' N, 73 º 37 ' E). In his first description, Werestschagin (1923) stated two localities: "Lake Zor Kul", and "Lake Yashilkul", both from East Pamirs. Smirnov (1971) designated lectotypes from Lake Zorkul and clarified the type locality. Lectotype: Largest adult female (0.71 mm in length) in tube ZIN 1 / 43533. Unfortunately, this specimen is in a moderately bad state. Paralectotypes. Two adult and one juvenile females. Smirnov (1971, 1996) stated three specimens in this tube, but we found an additional juvenile female. Additional material examined. Tajikistan, East Pamirs: Few females from a temporary freshwater body NE of Lake Zorkul, coll. in 0 4.08. 1959 by A. I. Yankovskaya, NNS 1997 -043; female from Lake Yashilkul (altitude: 3700 m, 37 º 45 ' N, 72 º 52 ' E), coll. in 20.07. 1972 by unknown collector, NMK 1080; two females from a pool at E shore of Lake Kara-Kul (altitude: 4000 m, approximately 39 º02' N, 73 º 23 ' E), coll. in 20.07. 1959 by A. I. Yankovskaya, NMK 2302. Diagnosis. Parthenogenetic female. Body relatively transparent, of moderate height (Fig. 5 A, D), postero-ventral angle without denticles. No medial keel on dorsum (Fig. 5 B), valves with paired lateral projections (Fig. 5 C, E). Rostrum long, protruding ventrally behind apex of labral keel, with a pair of tubercles on tip (Fig. 5 F, H). Ocellus and compound eye of subequal size. Labral keel relatively small, with broadly rounded apex. Head shield posteriorly rounded, postpore distance = about 1.6 interpore distance. Reticulation obscure, setae at anterior margin lie at a distance from valve edge (Fig. 6 A); all setae of valve ventral margin exactly marginal (Fig. 6 C–D), setules on posterior margin of valve exactly marginal. Postabdomen wide, narrowing distally, preanal margin longer than anal margin, preanal and postanal angle well-defined, postanal margin with series of solitary postanal teeth, rarely few teeth from this series supplied with additional, smaller tooth (Fig. 6 E–F), postabdominal claw with two basal spines of remarkably different size (Fig. 6 G). Anntenna I relatively thick, not reaching tip of rostrum, with a low basal peg (Fig. 6 I). On antenna II, all apical "swimming" setae subequal in size, lateral seta on basal segment of endopod shorter than other setae (Fig. 6 J). Spine on proximal segment of exopod longer than half of next segment length. All thoracic limbs in general as in P. annandalei. On limb I accessory seta present, smallest ODL seta well-defined, distally with minute setules, two largest IDL setae subequal in size (Fig. 6 K), seta on endite 1 is long (Fig. 6 L). On inner-distal portion of limb II size of scrapers regularly decreasing basally, filter plate II with eight setae, filter plate III with eight setae, filter plate IV with six setae. Exopodite V without special projections distally to distal seta 1. Juvenile female with elongated body (Fig. 5 J), solitary postanal teeth on postabdomen (Fig. 6 H). Ephippial female. Unknown. Male. Described by Werestschagin (1923) inadequately, probably, it has only a single basal spine on postabdominal claw, series of fine setules instead of postanal teeth, three setae of IDL subequal in size. Size. Lectotype 0.71 mm, parthenogenetic females in our material 0.42–0.74 mm. Differential diagnosis. See differences from closest P. annandalei in Table 1. Distribution. Only described from high mountain lakes and associated pools (altitude:> 3700 m) in Tajikistan, East Pamirs. In pools near Lake Zorkul, P. pamirensis coexists with Pleuroxus n. sp, Dunhevedia cf. crassa King, 1853, Macrothrix tripectinata Weisig, 1934, Daphnia magna Straus, 1820 and D. cf. pulex Leydig, 1860 (Kotov 1999, 2008). Comments. Werestschagin's (1923) description of Cornuella pamirensis was relatively adequate, and illustrations were quite realistic. Werestschagin (1923) said nothing about differences of his "hornned" animal from Daday's (1908) taxon, because at that time horns in " Euryalona " annandalei were not known.Published as part of Kotov, Alexey A. & Sheveleva, Natalia G., 2008, Separation of Pleuroxus pamirensis (Werestschagin, 1923) from P. annandalei (Daday, 1908) (Cladocera: Chydoridae), pp. 25-38 in Zootaxa 1775 on pages 32-35, DOI: 10.5281/zenodo.18222

Pleuroxus annandalei Daday 1908

<i>Pleuroxus annandalei</i> (Daday, 1908) <p>Figs 1–4</p> <p> <i>Euryalona annandalei</i> Daday 1908: 328 –329, fig. 3a–c.</p> <p> <i>Sinopleuroxus annandalei</i> (Daday) in Chiang Sieh-chih 1963: 61–62 (in Chinese), 69 (in English), figs 41–46; Shen Chia-jui & Sung Ta-hsiang 1964: 64 (in Chinese), 68 (English).</p> <p> <i>Cornuella annandalei</i> (Daday) in Chiang Sieh-chin & Du Nan-shan 1979: 263–264, fig. 187.</p> <p> <i>Pleuroxus pamirensis</i> (Werestschagin) in Smirnov 1996: 67 –68 (only Mongolia), figs 252–253.</p> <p> <i>Pleuroxus</i> sp. in Pomazkova & Sheveleva 2006: 186, fig. 12.1.</p> <p> <b>Type series</b>. <i>Type locality</i>. "Rham-Tso, altitudine 4480.5 mtr., a superficie maris" (Daday 1908), Chumbi Valley region, South Tibet. <i>Type material</i>. Apparently lost, absent in Daday's collection (Forró & Frey 1982; rechecked by Dr L. Forró in 2007).</p> <p> <b>Material examined</b>. Mongolia. Many parthenogenetic females from Lake Khövsgöl (=Khubsugul) (51º05' N, 100º29' E), Baikal Rift System, coll. in 25.07.1997 by N. G. Sheveleva & Dulma A., AAK 2007- 322; a juvenile female from Achit Nuur (nuur = lake)(49º29' N, 90º30' E), unknown collector, AAK 2007-323 (from Smirnov's slide 3608).</p> <p> <b>Diagnosis.</b> Parthenogenetic female with body relatively transparent, of moderate height, postero-ventral angle without denticles. No medial keel on dorsum, valves with paired lateral projections of size greatly differing among populations. Rostrum long, protruding ventrally to apex of labral keel, with a pair of tubercles on tip. Ocellus and compound eye of subequal size. Labral keel relatively small, with rounded apex. Head shield posteriorly widely rounded, postpore distance = about 1.5–1.8 interpore distance. Valve with reticulation in its ventral portion, all setae of valve ventral margin exactly marginal, setules on posterior margin of valve exactly marginal. Postabdomen wide, narrowing distally, its preanal margin approximately as long as anal margin, preanal and postanal angle well-defined, postanal margin with series of 2–3 relatively small postanal teeth. Anntenna I relatively slender, not reaching tip of rostrum, with a strong basal peg. On antenna II, all apical "swimming" setae subequal in size, lateral seta on basal segment of endopod shorter than other setae. Spine on proximal segment of exopod significantly shorter then half of next segment length. On limb I accessory seta present, smallest ODL seta well-defined, distally with minute setules, two largest IDL setae subequal in size, on endite 1 seta i short. On inner-distal portion of limb II size of scrapers regularly decreasing basally, filter plate II with eight setae. On exopodite III setae 1 shortest among distal setae, filter plate III with eight setae. On inner portion of limb IV setae 2-4 with thick setules, filter plate IV with six setae. Exopodite V without special projections distally to distal seta 1. Juvenile female with solitary postanal teeth. Ephippial female and male unknown. Size up to 1 mm.</p> <p> <b>Redescription.</b> <i>Parthenogenetic female</i>. Body relatively transparent, in lateral view oval, of moderate height for the genus (body height/ body length = 0.70–0.75 in large adults), maximum height in middle (Fig. 1 A). Dorsal margin evenly arched from tip of rostrum to postero-dorsal angle, which is well-defined, posterior margin almost straight, postero-ventral angle broadly rounded, without any denticles, ventral margin with a slight projection somewhat anterior to its middle. Body moderately compressed laterally, without a dorsal medial keel, with lateral projections of size greatly differing among populations from small hillocks (Fig. 1 B– C) to distinct horns. Chinese authors (Chiang Sieh-chin & Du Nan-shan 1979) illustrated another, smaller, pair of projections in posterior half of valves, which were absent in our specimens. Parthenogenetic female carries one-two eggs.</p> <p>Head with a long rostrum, protruding downward (Fig. 1 D), its tip with a pair of tubercles (Fig. 1 E–F). Ocellus and compound eye of subequal size, the former lies near base of antenna I, closer to eye that no tip of rostrum. Labrum with fleshy main body supplied with lateral outgrowths, a relatively large distal labral plate and a relatively small (for the genus) medial labral keel, having rounded apex (Fig. 1 G–I) not reaching tip of rostrum. Head shield elongated, with maximum width anterior to level of mandibular articulation, its posteriormost portion rounded (Fig. 1 J). Two major head pores, postpore distance = about 1.5–1.8 interpore distance (Fig. 1 K). Lateral head pores minute, normally located asymmetrically to midline. Valve with a reticulation expressed in its ventral half (Fig. 1 M); valve portion contacting head shield with a special flap on its inner side; in anterior portion of valve, setae located at a distance from valve margin (Fig. 1 N–O); ventral margin armed with numerous setae of different size in different regions, all plumose and located exactly marginally (Fig. 1 P–S); posterior valve margin with additionally chitinised rim and a row of fine setules.</p> <p>Abdomen short, its first (basalmost) segment with convex dorsal margin. Postabdomen wide, its ventral margin almost straight (Fig. 2 A–B). Preanal margin slightly concave, approximately as long as anal margin, preanal and postanal angle well-defined, postanal margin equal or slightly longer than anal margin, dorso-distal angle widely rounded and slightly prominent distally, inflated basis of claws bordered from postanal margin by a distinct depression. Postanal margin provided with series of 2–3 relatively small postanal teeth. Laterally on postabdomen fascicles of short, fine setules. Postabdominal seta as long as preanal plus anal margin or shorter, with distal segment setulated. Postabdominal claw shorter anal margin, massive, evenly curved, with setules along ventral margin, and two basal spines, proximal one about half size of distal one (Fig. 2 C– D).</p> <p>Antenna I small, its length more than half labral keel length, slightly narrowing distally, with a welldefined basal peg (Fig. 2 E–F). Antennular sensory seta slender, longer than half the antenna I, arising at middle to one third of antennular length from distal end directly from antenna I body, on a small prominence. Nine aestetascs of differing size. Antenna II (Fig. 2 G) relatively short, coxal part with two sensory setae, basal segment robust, with a rudimentary distal spine. Antennal branches relatively elongated, endopod longer than exopod, all segments cylindrical (Fig. 2 H), antennal formula, setae 0-0-3/1-1-3, spines 1-0-1/0-0-1. All apical "swimming" setae of endopod subequal in size, with chitinous insertions within distal segments (Fig. 2 I), lateral seta on basal segment of endopod shorter than other setae. Spine on proximal segment of exopod significantly shorter then half of next segment length. Exopod and endopod apical spines subequal in size.</p> <p>Limb I (Fig. 3 A–B). Accessory seta present, ODL with a long seta armed with short setules distally, and a small seta with short, setulated distal segment. IDL of size similar with ODL, supplied with several series of setules; first IDL seta short, naked, second and third IDL setae subequal in size and similarly armed distally with fine setules. Endite 3 with three soft posterior setae (a–c) and stiff anterior seta 1 of similar length. Endite 2 with short posterior setae d and e, long seta f, and thin anterior seta 2 armed with minute setules distally. Endite 1 with long posterior setae g–h, a short seta i, a very short seta j, and anterior seta 3 similar to seta 2. Fascicles of thin setules on inner face of limb, plus bunches of larger setules at ventral margin of limb. Two slender ejector hooks of subequal size. A short seta, and a setulated hillocks, both remnants of gnathobase I, on limb base.</p> <p>Trunk limb II. Exopodite subquadrangular, with a naked seta. Inner portion of limb with eight scrapers (Fig. 3 C: 1–8), setae 1–2 specially long, with finer setules. A series of small projections posteriorly to distal setae, and a small sensillum near scraper 4. Distal armature of gnathobase with a bunch of setules and four setae (Fig. 3 D: 1–4). Filter plate II with eight setae, two distal members shorter than the rest.</p> <p>Trunk limb III. Exopodite sub-rectangular, with four distal setae (Fig. 3 E: 1–4) and three lateral setae (5– 7). Distal endite with three anterior setae (Fig. 3 F: 1–3), all with minute setules distally, of them two distal setae (1–2) long, basalmost seta (3) short. Small sensillae near bases of setae 2 and 3. Basal endite with four anterior setae (4–7), armed with fine setules distally, a sensillum with pointed tip near seta 4. On posterior surface of limb, six soft setae (a–f) bilaterally armed with sparse, fine setules. Gnathobase not clearly separated from basal endite. Distal armature of gnathobase a with large, bottle-shaped sensillum, three setae and a bunch of setules. Filter plate III with eight setae, distalmost seta shorter than the rest.</p> <p>Trunk limb IV. Exopodite wide, subovoid, with seven setae of unequal size (Fig. 3 G: 1–7). Inner-distal portion of limb IV with four marginal setae (Fig. 3 H: 1–4). Distalmost seta (1) stout, with minute setules on distal segment, setae 2–4 with thick basal segments and slender, setulated distal segments, sensillae located near setae 2 and 3. On posterior surface, four soft setae (a–d), Gnathobase distal armature with four setae. Filter plate with six setae.</p> <p>Trunk limb V. Exopodite large, subovoid, with a single distal seta (Fig. 3 I: 1) and three lateral setae (2–4), no special projections distally to seta 1. Inner limb portion as elongated, flat lobe, with setulated inner margin, supplied with setulated setae 1 and 2. Distal armature of gnathobase as a single projection, filter plate V with four long setae.</p> <p> <i>Juvenile female.</i> Body more elongated as compared with adult (body height/ body length = 0.64–0.68), with almost straight dorsal margin of carapace and less distinct postero-dorsal angle (Fig. 4 A). Labral keel broad (Fig. 4 B), relatively larger as compared with adult. Postabdomen with solitary postanal teeth (Fig. 4 C, F), postabdominal claw (Fig. 4 D, G) in general as in adult. Antenna I with sensory seta in distal half of its body and less distinct basal peg (Fig. 4 E).</p> <p> <i>Ephippial female, male</i>. Unknown.</p> <p> <b>Size.</b> Parthenogenetic females in our material from Khövsgöl 0.46–0.85 mm, 0.9–1.0 mm according to Daday (1908).</p> <p> <b>Differential diagnosis.</b> See differences from closest <i>P. pamirensis</i> in Table 1.</p> <p> <b>Distribution.</b> <i>P. annandalei</i> was also found by M. Alonso (pers. comm.) in a small unnamed lake (48º23'47'' N, 88º53'59'' E) near Dayan Nuur in Mongolian Altai. So, the species is distributed on the Tibetan Plateau (Tibet Autonomous Region and Qinghai Province of China), Baikal Rift System and Mongolian Altai.</p> <p> <b>Comments.</b> Daday (1908) missed the presence of lateral projections on valves in his first description of <i>P. annandalei</i>. Earlier Kotov & Štifter (2005) found that Daday also missed the lateral horns in his description of " <i>Ilyocryptus sordidus</i> (Liévin, 1848) " from Paraguay, subsequently described as <i>I. paranaensis</i> Paggi, 1989. Observations of a specimen in lateral position only, was characteristic of many earlier cladoceran investigators and led to mistakes.</p> <p> Chiang Sieh-chih (1963) and then Chiang Sieh-chin & Du Nan-shan (1979) correctly found that their "horned" chydorids belong to Daday's taxon. But their illustrations are not fully adequate. For example, the posterior gut illustrated by them was too narrow. In reality, it is obvious from their figures that their female had an anal margin longer than the preanal margin, which is characteristic of <i>P. annandalei</i>.</p> <p> Upon re-examination of material from Smirnov (1996), we found that a female from Achit Nuur with solitary postanal teeth on the postabdomen, which was identified by him as <i>P. pamirensis</i>, is actually a juvenile <i>P. annandalei</i> (length 0.60 mm).</p>Published as part of <i>Kotov, Alexey A. & Sheveleva, Natalia G., 2008, Separation of Pleuroxus pamirensis (Werestschagin, 1923) from P. annandalei (Daday, 1908) (Cladocera: Chydoridae), pp. 25-38 in Zootaxa 1775</i> on pages 26-32, DOI: <a href="http://zenodo.org/record/182222">10.5281/zenodo.182222</a&gt

Alona floessneri Sinev, Alonso & Sheveleva, 2009, sp. nov.

<i>Alona floessneri</i> sp. nov. <p>(Figs. 5–8)</p> <p> <b>Etymology.</b> The species is named after German cladocerologist Dietrich Flössner.</p> <p> <b>Type locality.</b> Uvs Nuur (Nuur = lake), Uvs aimag, north-west Mongolia –Russian border, 50º06’55”N, 92º24’25”E.</p> <p> <b>Holotype.</b> parthenogenetic female, preserved in 80% ethanol, deposited at ZMOU, Ml-79.</p> <p> <b>Paratypes.</b> 18 parthenogenetic females from type, preserved in 80% ethanol, deposited at ZMOU, Ml-80. 20 parthenogenetic females, 5 gamogenetic females and 8 males from lake Khar Nuur, Hövsgöl aimag, North –central Mongolia. (49º23’38”N, 98º25’19”E), preserved in 80% ethanol, deposited at the first author personal collection in Institute for Ecology and Evolution, Moscow.</p> <p> <b>Diagnosis.</b></p> <p> <i>Female</i>. Of moderate size, length up to 0.56 mm. Body irregular oval, of moderate height, height /length ratio about 0.70–0.74, maximum height in the middle of the body. Whole carapace covered by narrow longitudinal lines. Head shield with broadly rounded posterior margin, rostrum short and rounded. Three narrowly connected major head pores, central pore located at the middle between other pores. PP about 0.8– 0.9 IP. Lateral head pores dot-like, located at 1.0–1.2 IP distance from midline. Labral keel suboval, with rounded apex, without clusters of setules on posterior margin.</p> <p>Postabdomen of moderate width (length about 2.5–2.6 height), with almost parallel margins and broadly rounded dorsodistal angle. Dorsal margin with distal part about 1.9–2.2 times longer than preanal one, with postanal portion 1.4–1.6 times longer than anal. Preanal angle moderately prominent, an incursion in place of postanal angle. Postanal portion of dorsal margin convex, anal portion almost straight. Eight–ten clusters of small marginal denticles along preanal margin, decreasing in size basally, and 3 wide clusters of very short setules on anal margin. About 10 lateral fascicles of setules along dorsal margin; 6 fascicles in postanal portion very wide, with setules 2 time longer than marginal denticles. All setules in fascicles of similar width. Postabdominal claw of moderate length, slightly longer than preanal portion of postabdomen. Basal spine long and thin, about 1/3 of length of claw.</p> <p>Antennula with 9 terminal aesthetascs, longest of them of about half length of antennula. Antennal formula, setae 0-0-3/1-1-3, spines 1-0-1/0-0-1. Seta arising from basal segment of endopodite as long as endopodite. Spine on basal segment of exopodite shorter than middle segment. Spine from apical segment of exopodite slightly shorter than this segment. Apical spine of endopodite of same length as this segment.</p> <p>Limb I with very long accessory seta, IDL of limb I with three setae, IDL seta 1 very small, two others armed with short setules distally. Exopodite of limb II with very small seta, scraping spines not differentiated. Exopodite of limb III with six setae, seta 3 being longest, seta 4 three times shorter than seta 5. Exopodite IV with 6 setae, setae 4 and 6 of exopodite IV about 2/3 length of seta 5. Exopodite V with 4 setae, filter plate I consist of single seta. Epipodites IV and V without projections. Limb VI absent.</p> <p> <i>Male.</i> Body regular oval, of moderate height, height/length ratio about 0.66–0.70, maximum height at the middle of the body. Postabdomen short, with narrowing anal portion, subrectangular postanal portion, and a distinct bulk at ventrodistal portion of postabdomen.. Dorsodistal angle not defined. Sperm duct openings located almost at the end of postabdomen. Clusters of short setules in place of marginal denticles, lateral fascicles of setules same as in female. Postabdominal claw 1.5 times shorter than that of female, basal spine 2 times shorter than in female.</p> <p>Antennule with 10 terminal and 2 lateral aesthetascs. Male seta arising at 1/4 length from tip, about 1/3 of antennule length. Thoracic limb I with U-shaped copulatory hook, IDL seta 1 absent, setae 2 and 3 subequal in length, male seta thick, curved, as long as seta 3.</p> <p> <b>Description.</b></p> <p> <b>Parthenogenetic female</b>. <i>General</i>: In lateral view body irregular oval, moderately high (Fig. 5 A–B, 6A– D). Maximum height in the middle of the body. In adults height/length ratio about 0.70–0.74. Dorsal margin arched, without any depression at the border of valves and head shield. Posterodorsal and posteroventral angles broadly rounded. Posterior margin almost straight. Posterodorsal angle with about 100 setules of equal size, reaching almost to the middle of the posterior margin of valves. A row of about 110 smaller setules along the posterior margin (Fig. 5 D, 6E) at some distance from it on inner side of carapace. Ventral setae as in previous species (Fig. 5 C). Anteroventral angle rounded. Whole carapace covered by narrow longitudinal lines (Fig. 6 A–D). Head as in previous species.</p> <p> <i>Head shield</i> with gently poligonal sculpture (Fig. 6 A–C)). Head pores (Fig. 6 F, 7A–B) and labrum (Fig. 7 C–E) as in previous species.</p> <p> <i>Postabdomen</i> (Fig. 5 F–G, 6G–H) of moderate width, weakly narrowing in postanal portion, with broadly rounded dorso-distal angle. Length about 2.5–2.6 height. Ventral margin almost straight. Incursion between basis of claws and distal margin unclear. Distal margin weakly convex. Dorsal margin with distal part about 1.9–2.2 times longer than preanal one, with postanal portion 1.4–1.6 times longer than anal. Preanal angle well defined, postanal angle as clear incursion. Postanal portion of dorsal margin convex, anal portion almost straight. Preanal margin almost straight. Eight-ten clusters of small marginal denticles along preanal margin, decreasing in size basally, and 3 wide clusters of very short setules on anal margin. A row of about 10 lateral fascicles of setules along dorsal margin; 6 fascicles in postanal portion very wide, with setules 2 times longer than marginal denticles, fascicles in anal portion 2 times shorter, of similar width. All setules in fascicles of similar width. Additional fascicles of setules located above the main row in anal portion. Postabdominal claw of moderate length, slightly shorter than preanal portion of postabdomen. Basal spine long and thin, about 1/3 of length of claw.</p> <p> <i>Antennule</i> similar to that of the previous species (Fig. 7 F), but broader, height/width ratio about 2.5. Antenna as in the previous species (Fig. 6 I, 7G).</p> <p> <i>Thoracic limbs</i>: five pairs. Limb I as in previous species (Fig. 7 H–I), but setae of endite III clearly differentiated in size. Limb II as in previous species (Fig. 7 J). Limb III as in previous species (Fig. 7 K–M), but seta 5 of exopodite armed with small, thin setules. Limb IV as in previous species (Fig. 7 N–O), but setae 6 and 4 of exopodite considerable shorter in comparison with seta 5. Limb V as in previous species (Fig. 7 P).</p> <p> <b>Ephippial female</b> (Fig.8 A) similar in shape to parthenogenetic female, body height/body length: 0.66– 0.70. Carapace in contact with ventral border of ephippium with polygons in place of longitudinal striae. Ephippium dark brown. Ocellus of same size as eye or slightly larger.</p> <p> <b>Male</b>. General shape of adult male (Fig. 8 B) regularly oval, with convex posterior margin, body height/ body length = 0.66–0.70. Ocellus and eye of same size as in parthenogenetic female.</p> <p> <i>Postabdomen</i> (Fig. 8 C–D) short, with narrowing anal portion. Postanal portion subrectangular with distinct ventrodistal bulge. Dorso-distal angle not defined. Preanal and postanal angles well defined. Distal part of postabdomen 1.1 times longer than preanal. Sperm ducts opening ventrally at the end of postabdomen, very close to base of claws.</p> <p>Clusters of short setules in place of marginal denticles, lateral fascicles of setules same as in female. Postabdominal claw 1.8 times shorter than that of ephippial female, basal spine 3 times shorter than claw.</p> <p> <i>Antennule</i> (Fig. 8 E) and <i>thoracic limb I</i> (Figs 8 F–H) as in previous species.</p> <p> <b>Size:</b> adult females, length 0.43–0.55 mm, height 0.30–0.35 mm. Ephippial females, length 0.45–0.57 mm, height 0.30–0.38 mm. Males, length 0.34–0.37 mm, height 0.24–0.25 mm.</p> <p> <b>Remarks.</b> <i>Alona floessneri</i> <b>sp. n.</b> differs from <i>A. irinae</i> <b>sp. n.</b> in body shape, with almost straight posterior margin, in sculpture of the carapace, composed of narrow longitudinal lines, in peculiar shape of the male and female postabdomen, in presence of short groups of distal marginal denticles of female postabdomen, and in shorter setae 4 and 6 of exopodite IV. <i>Alona floessneri</i> <b>sp. n.</b> differs from <i>A. salina</i> in the morphology of the lateral fascicles of setules of postabdomen, in IDL morphology, in the shape of male postabdomen, and in its smaller size. Differences between these species are summarized in Table 1.</p> <p> <b>Distribution and ecology</b>. <i>A. floessneri</i> <b>sp. nov.</b> has a wide distribution in saline and subsaline water bodies in Mongolia, which supports the idea that it can appear in similar environments in other Asian countries.</p> <p> In Mongolia this species is known from Uvs Nuur (85), Kholboo Nuur (109: 45º15’11.9”N, 114º06’45.5”E), Sumiin Bulagriin Nuur (139: 49º08’39”N, 114º52’28.6”E), Khar Nuur (215) and Zuun Khooloi Nuur (309: 47º17’52.3”N, 92º43’53.0”E). In brackets reference numbers and coordinates of the sampling sites in the website <b>http://www.geodata.es/mongolian_lakes</b> where further information and pictures of the water bodies can be seen.</p> <p> Uvs Nuur is a large (361459 hectares) permanent mesotrophic alkaline salt lake with salinity about 13 g /l, Na/Mg/Cl/SO4 type, pH about 9.0 (Flössner et al., 2005), and water electrical conductivity of 29400 μS/cm. Macrophytes are scarce. We presume that the species was already reported from this lake by Flössner <i>et al</i>. (2005) as <i>Alona elegans,</i> together with other two halobiont crustaceans, the cladoceran <i>Moina salina</i> Daday, 1888, and the calanoid <i>Arctodiaptomus salinus</i> (Daday, 1885). The presence of <i>Alona elegans</i> sensu stricto in the lake is quite improbable, since it is a freshwater species, never reported from saline water (Alonso 1996; Flössner 2000).</p> <p> Zuun Khooloi Nuur is a shallow, permanent, 773 hectare playa lake. Water is mesotrophic and highly mineralised (10300 μS/cm) and alkaline (pH 9.1). Accompanying halobiont crustacean species were the cladoceran <i>Moina salina</i> and the calanoid <i>Metadiaptomus asiaticus</i> (Ul’yanin 1875), together with the halotolerant <i>Daphnia magna</i> Straus, 1820.</p> <p> Kholboo Nuur (149 hectares and 8120 μS/cm), Sumiin Bulagriin Nuur (1,700 hectares and 7200 μS/cm), and Khar nuur (7 hectares and 13300 μS/cm) are shallow permanent or semi permanent lakes. As in the previous ones, water is highly mineralised but also very turbid because of suspended clay particles. The crustacean community in these lakes is as well characterized by halobiont and halo-tolerant species, namely the calanoid <i>Arctodiaptomus rectispinosus</i> Kikuchi, 1940, <i>Daphnia magna</i> and <i>Moina brachiata</i> (Jurine, 1820) in Kholboo; <i>M. brachiata</i> in S. Bulagriin; <i>Daphnia triquetra</i> G.O.Sars, 1903, <i>M. brachiata</i> and the calanoid <i>Metadiaptomus asiaticus</i> in Khar.</p>Published as part of <i>Sinev, Artem Y., Alonso, Miguel & Sheveleva, Natalia G., 2009, New species of Alona from South-East Russia and Mongolia related to Alona salina Alonso, 1996 (Cladocera: Anomopoda: Chydoridae), pp. 1-23 in Zootaxa 2326</i> on pages 10-15, DOI: <a href="http://zenodo.org/record/192078">10.5281/zenodo.192078</a&gt

Alona salina Alonso 1996

<i>Alona salina</i> Alonso, 1996 <p>(Figs. 9–11)</p> <p> <i>Alona</i> sp. <i>—</i> Alonso, 1990: 224 –225, fig. 2a–b. <i>Alona salina</i> Alonso, 1996: 335 –337, fig. 150.</p> <p> <b>Material examined.</b> Parthenogenetic and ephippial females, adult and juvenile males (over 250 specimens in total) from Laguna de la Dehesilla, 39º25’19.08”, N, 2º50’26.47”E, neighborhood of Mota Del Cuervo, Castilla La Mancha, Spain, 0 1.05.1999.</p> <p> <b>Description.</b> <i>Parthenogenetic female</i>. General: In lateral view body regular oval, moderately high in adult (Fig. 9 C), lower, irregular oval in juveniles (Fig. 9 A–B). Maximum height in adult at the middle of the body; in juveniles, in the second quarter of the body. In juveniles of both instars height /length ratio about 0.60; in adults 0.64–0.68. Dorsally arched, without any depression at the border of valves and head shield. Posterodorsal and posteroventral angles broadly rounded. Posterior margin convex. Posterodorsal angle with about 50 setules of similar size, much thicker than in two previous taxa, separated into several groups. A row of about 100 smaller setules along the posterior margin (Fig. 9 E), at some distance from it on inner side of carapace. Ventral setae as in two previous species. Anteroventral angle rounded. Carapace covered by narrow longitudinal lines and hexagons, clearly visible under optic microscope (Fig. 9 D).</p> <p>Head relatively small, triangle-round in lateral view, rostrum short, pointing downward. Eye larger than ocellus. Distance from tip of rostrum to ocellus equal or slightly greater than that between ocellus and eye.</p> <p>Head shield with gently polygonal structures (Fig. 9 A–F). Three narrowly connected major head pores, connection between them more narrow than in two previous species (Fig. 10 A–B). Middle pore slightly smaller than others, located at the middle between others. PP about 0.6–0.8 IP. Lateral head pores slightly elongated, located about 1.1–1.2 IP distance from midline, at the level between the middle and anterior major head pores. Labrum (Fig. 10 C–E) as in two previous species.</p> <p> <i>Postabdomen</i> (Fig. 9 G–H) wider than in two previous species, weakly narrowing in postanal portion, with broadly rounded dorsodistal angle. Length about 2.3–2.5 height. Ventral margin almost straight. Inflated basis of claws bordered from distal margin by clear incision. Distal margin almost straight. Dorsal margin with distal part about 1.8–2.0 times longer than preanal one, with postanal and anal portion subequal in length. Postanal portion of distal margin weakly convex, anal portion concave. Preanal angle moderately defined, postanal angle not defined or weakly defined. Preanal margin almost straight.</p> <p>Postabdomen with 8–10 clusters of small marginal denticles and setules, decreasing in size basally, along preanal and anal margin; 8–10 lateral fascicles of setules; 6 or 7 fascicles in postanal portion wide, with setules two times longer than marginal denticles, fascicles in anal portion much smaller. First setules in postanal fascicles more thick than others. Postabdominal claw of moderate length, slightly shorter than preanal portion of postabdomen. Basal spine thin, about 1/4 of length of claw, a cluster of long setules located near its base.</p> <p> <i>Antennule</i> (Fig. 10 F) same as in <i>A. floessneri</i> <b>sp. nov</b>. Antenna (Fig. 10 G) same as in two previous species.</p> <p> <i>Thoracic limbs</i>: five pairs. Limb I as in two previous species (Fig. 10 H–I), but IDL setae 2 and 3 more strong and robust. Setae of endite III slightly differentiated in size. Limb II as in two previous species (Fig. 10 J). Limb III as in two previous species (Fig. 10 K–L), but seta 5 of exopodite armed with long, thick setules. Limb IV as in two previous species (Fig. 10 M–N), but setae 6 and 4 of exopodite almost as long as seta 5. A small sensillum on inner portion of the limb between bases of two basalmost flaming-torch setae, this structure was not observed in two previous species. Limb V as in two previous species (Fig. 10 O).</p> <p> <b>Ephippial female</b> (Fig. 11 A) with higher body than parthenogenetic female, ephippium dark yellowbrown, with prominenet sculpture in shape of longitudinal lines thicker than on the rest of valves, in some specimens irregular polygons are present in lower portion of ephippium.</p> <p> <b>Male</b>. General shape of juvenile males of instar I (Fig. 11 B) and II (Fig. 11 E) similar to that of juvenile females of same instar. General shape of adult male (Fig. 11 I) similar to that of instar II juvenile female, body height/body length = 0.63–0.65. Ocellus and eye of same size as in female.</p> <p> <i>Postabdomen</i>. In juvenile males of instar I similar to that of juvenile female (Fig. 11 C), with sperm duct openings located before the middle of ventral margin. In juvenile males of instar II, shorter than that of female (Fig. 11 F), with clear step on ventral margin in region of gonopores. Armament of postabdomen and postabdominal claw same as in female in both juvenile instars. In adult male, postabdomen short, with almost parallel margins in distal portion, dorso-distal angle broadly rounded (Fig. 11 J). Preanal angle not defined, postanal angle well-defined. Distal part of postabdomens 1.3 times longer than preanal. Sperm duct openings located almost at the end of postabdomen. Clusters of short setules in place of marginal denticles, lateral fascicles of setules same as in female. Postabdominal claw 1.5 times shorter than that of female, basal spine of same size as in female.</p> <p> <i>Antennule</i>. In instar I male same as in female. In instar II male antenule broader than in female, with anlage of male seta, aestetascs same as in female (Fig. 11 G). In adult male antennule much shorter than in female (Fig. 11 K), with 10 terminal and 2 lateral aesthetascs as long as terminal ones. Male seta arising at 1/3 length from tip, about 1/3 of antennule length.</p> <p>Thoracic limb I. In instar I male with short anlage of copulatory hook, IDL same as in female (Fig. 11 D). In instar II male, copulatory hook curved (Fig. 11 H). Ventral face of limb with anlage of copulatory brush seta and a peculiar hillock above it, not present in any other instar. IDL with anlage of male seta, other setae same as in female. In adult male, limb I more stout than that of female (Fig. 10 L), with U-shaped copulatory hook. Copulatory brush present. Row of about 15 short setules on ventral face of limb under copulatory brush (Fig. 11 M). IDL seta 1 absent, setae 2 and 3 setae subequal in length, much thinner than in female, male seta thick, curved, as long as seta 2.</p> <p> <b>Size.</b> In the studied population, instar I juvenile females length 0.29–0.32 mm, height 0.19–0.20 mm; instar II, length 0.35–0.38 mm, height 0.23–0.24 mm; adult female, length 0.39–0.61 mm, height 0.27–0.34 mm; instar I juvenile males, length 0.29–0.30 mm, height about 0.19 mm; instar II, length 0.31–0.33 mm, height 0.19–0.22 mm; adult males length 0.36–0.39 mm, height 0.22–0.24 mm.</p> <p> Our data on morphology of <i>Alona salina</i> fully agree with those in the previous reports (Alonso 1990, 1996) with one exception. Alonso (1996) mistakingly reported that the antenna of <i>A. salina</i> lack seta on the middle segment of exopodite. This seta is present. The morphology of ephippium of <i>A. salina</i> agrees with that reported by Vandekerkhove et al. (2004).</p> <p> <b>Distribution and ecology</b>. <i>A. salina</i> is known from permanent and temporary subsaline and saline water bodies on the Iberian Peninsula. Alonso (1996) considers it an Iberian endemic, typical of the Spanish endorheic systems. According to Boronat <i>et al.</i> (2001), it occurs at the wide diapason of salinities ranging from 5.7 to more that 100 mg /l. In the Iberian Peninsula, <i>A salina</i> coexists with halo-tolerant cladocerans namely <i>Daphnia magna,</i> <i>Daphnia akinsoni</i> Baird, 1859, <i>Moina brachiata</i> and <i>Dunhevedia crassa</i> King, 1853, but also with true halophyle cladocerans such as <i>Moina salina</i> and <i>Daphnia mediterranea</i> Alonso, 1985 (Alonso 1998).</p>Published as part of <i>Sinev, Artem Y., Alonso, Miguel & Sheveleva, Natalia G., 2009, New species of Alona from South-East Russia and Mongolia related to Alona salina Alonso, 1996 (Cladocera: Anomopoda: Chydoridae), pp. 1-23 in Zootaxa 2326</i> on pages 15-20, DOI: <a href="http://zenodo.org/record/192078">10.5281/zenodo.192078</a&gt

Redescription of Daphnia turbinata Sars, 1903 (Crustacea: Cladocera: Daphniidae)

Zuykova, Elena I., Sheveleva, Natalia G., Kotov, Alexey A. (2019): Redescription of Daphnia turbinata Sars, 1903 (Crustacea: Cladocera: Daphniidae). Zootaxa 4658 (2): 317-330, DOI: https://doi.org/10.11646/zootaxa.4658.2.

Composition and Structure of Lake Kotokel

Представлены материалы по зоопланктону озера Котокельского, которое находится в непосредственной близости от Байкала. Определен таксономический состав, показатели биоразнообразия и структуры, сезонная и пространственная динамика зоопланктона в подледный и период открытой воды. Приведена сравнительная характеристика видового состава и количественных показателей зоопланктона с данными за 1966, 1979, 1986 гг. (Антипова, Помазкова, 1971; Сорокина, 1982; Дзюменко, 1988). Данные по зоопланктону (разнообразие, количество видов-индикаторов трофности, число видов в структурообразующем комплексе, индекс разнообразия по биомассе, максимальная и средняя численность и биомасса; ход кривой сезонной динамики), полученные в результате наших исследований, подтверждают эвтрофный тип озера.This paper presents results on zooplankton studies of Lake Kotokel which is located in the immediate vicinity of Lake Baikal. The authors studied taxonomic composition, biodiversity, structure, seasonal and spatial dynamics of zooplankton during ice and free-ice periods. Data on species composition and quantitative parameters of zooplankton were compared with those obtained for 1966, 1979 and 1986 (Antipova, Pomazkova, 1971; Sorokina, 1982; Dzyumenko, 1988). Results of zooplankton research (diversity, a number of species-indicators of trophic level, a number of species in the structure-forming complex, biomass diversity, maximal and average abundance and biomass, and a curve of seasonal dynamics) confirm that Lake Kotokel is of a mesotrophic type

Composition and Structure of Lake Kotokel

Представлены материалы по зоопланктону озера Котокельского, которое находится в непосредственной близости от Байкала. Определен таксономический состав, показатели биоразнообразия и структуры, сезонная и пространственная динамика зоопланктона в подледный и период открытой воды. Приведена сравнительная характеристика видового состава и количественных показателей зоопланктона с данными за 1966, 1979, 1986 гг. (Антипова, Помазкова, 1971; Сорокина, 1982; Дзюменко, 1988). Данные по зоопланктону (разнообразие, количество видов-индикаторов трофности, число видов в структурообразующем комплексе, индекс разнообразия по биомассе, максимальная и средняя численность и биомасса; ход кривой сезонной динамики), полученные в результате наших исследований, подтверждают эвтрофный тип озера.This paper presents results on zooplankton studies of Lake Kotokel which is located in the immediate vicinity of Lake Baikal. The authors studied taxonomic composition, biodiversity, structure, seasonal and spatial dynamics of zooplankton during ice and free-ice periods. Data on species composition and quantitative parameters of zooplankton were compared with those obtained for 1966, 1979 and 1986 (Antipova, Pomazkova, 1971; Sorokina, 1982; Dzyumenko, 1988). Results of zooplankton research (diversity, a number of species-indicators of trophic level, a number of species in the structure-forming complex, biomass diversity, maximal and average abundance and biomass, and a curve of seasonal dynamics) confirm that Lake Kotokel is of a mesotrophic type

Contrasting phylogeographic patterns and demographic history in closely related species of Daphnia longispina group (Crustacea: Cladocera) with focus on North-Eastern Eurasia.

Species with large geographic distributions present a challenge for phylogeographic studies due to the logistic difficulties of obtaining adequate samples. Daphnia O.F. Müller (Anomopoda: Daphniidae) is a model genus for evolutionary biology and ecology, but many regions such as the remote areas of Siberia, remain poorly studied. Here we examined genetic polymorphism in the ribosomal 12S and the protein-coding ND2 mitochondrial genes of three closely related taxa of the Daphnia (Daphnia) longispina complex, namely D. galeata Sars, D. longispina O.F. Müller and D. dentifera Forbes. We estimated the phylogenetic relationships among these taxa based on a concatenated alignment of these two genes. Using sequences from the present study and those available in GenBank, we investigated the geographic distributions of the mitochondrial haplotypes of these species and proposed an evolutionary scenario for each taxon. Network structures, haplotype distribution patterns, and FST values indicated significant differences in the evolutionary history of the examined species. Our analysis of D. galeata populations confirmed its recent and fast expansion, without a previous phase of a strong population disconnection. In contrast, the high haplotype diversity in D. dentifera and D. longispina could be explained by the survival of different phylogroups in several glacial refugia located in different geographic regions. For all studied species, maximum haplotype diversity was recorded in the remote regions of Siberia-lakes of the Yenisei River and Transbaikalia. Our study is an important step in our understanding of the evolutionary history of the Daphnia longispina group and provides further evidence of the biogeographic significance of Siberia for freshwater taxa

Structure and Quantitative Characteristics of Zooplankton and Zoobenthos in the Upper Lena River Basin

Представлены материалы по таксономическому составу, структуре и количественным характеристикам зоопланктона и зообентоса русловой части, пойменных водоемов и заливов верхнего участка р. Лена. Видовой состав фауны планктона включает 76 видов, в том числе реликт северного происхождения – Cyclops scutifer, обитающий в оз. Исток Лены. По структурным характеристикам зоопланктона трофический статус водоемов изменяется от олиготрофного до α-мезотрофного типа. Основу зообентоса составляют личинки стрекоз, поденок, ручейников и хирономидThe authors provide data on the taxonomic composition, structure and quantitative characteristics of zooplankton and zoobenthos from the mainstream, floodplain water bodies and side channels of the upper Lena River. A total of 76 species of plankton were recorded, including the northern relict C. scutifer, found in Lake Istok on Lena River. Judging by the structure and quantitative characteristics of zooplankton, the trophic status of these waters ranges from oligotrophic to α-mesotrophic. The zoobenthos is composed mainly of dragonfly larvae, mayflies, caddisflies and chironomid