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Key for Anthalona species of South-East Asia 1a. IDL seta 3 with long distal portion, armed with thin setules of equal thickness.................................................................................................. Anthalona sanoamuangae Sinev & Kotov, 2012. 1b. IDL seta 3 with thick spine at the middle and shortened distal portion armed with thin setulae, or IDL seta 3 armed with several long spines.......................................................................................... 2 2a. IDL seta 3 with thick spine at the middle and shortened distal portion armed with thin setulae......................... 3 2b. IDL seta 3 armed with several long spines.................................................................. 5 3a. Cosmaria of lateral pores flower-like............................................. Anthalona milleri (Kiser, 1948) 3b. Cosmaria of lateral pores bilobed......................................................................... 4 4a. IDL setae 2-3 thick, curved, claw-like; distal portion of seta 3 shorter than its basal spine. Anterior margin of labral keel with a blunt denticle bearing a spinule.......................... Anthalona harti harti Van Damme, Sinev & Dumont, 2011. 4b. IDL setae 2-3 moderately thick, weakly curved; distal portion of seta 3 longer than its basal spine. Anterior margin of labral keel with a blunt denticle lacking a spinule........................ Anthalona obtusa Van Damme, Sinev & Dumont, 2011. 5a. Posterior setae of valves short, posteriormost setae located before posteroventral angle of valves. IDL setae 2-3 armed with spines of similar thickness and length................... Anthalona spinifera Tiang-nga, Sinev & Sanoamuang, 2016. 5b. Posterior setae of valves long, posteriormost setae located at posteroventral angle of valves. IDL setae 2-3 with basal spine much thicker and longer than others............................................. Anthalona vandammei sp. nov., Published as part of Sinev, Artem Y., Tiang-Nga, Supatra & Sanoamuang, Laorsri, 2023, Anthalona vandammei sp. nov. from Thailand, a sibling species of Neotropical Anthalona brandorffi (Sinev & Holwedell, 2002) (Cladocera: Anomopoda: Chydoridae), pp. 67-78 in Zootaxa 5230 (1) on page 76, DOI: 10.11646/zootaxa.5230.1.4, http://zenodo.org/record/7550516, {"references":["Sinev, A. Y. & Kotov, A. A. (2012) New and rare Aloninae (Cladocera: Anomopoda: Chydoridae) from Indochina. Zootaxa, 3334 (1), 1 - 28. https: // doi. org / 10.11646 / zootaxa. 3334.1.1","Van Damme, K., Sinev, A. Y. & Dumont, H. J. (2011) Separation of Anthalona gen. n. from Alona Baird, 1843 (Branchiopoda: Cladocera: Anomopoda): morphology and evolution of scraping stenothermic alonines. Zootaxa, 2875 (1), 1 - 64. https: // doi. org / 10.11646 / zootaxa. 2875.1.1","Tiang-nga, S., Sinev, A. Y. & Sanoamuang, L. (2016) A new species of the genus Anthalona Van Damme, Sinev and Dumont, 2011 (Cladocera: Anomopoda: Chydoridae) from North-East Thailand. Zootaxa, 4150 (1), 93 - 100. https: // doi. org / 10.11646 / zootaxa. 4150.1.6"]}

Sinev, Artem Y., Tiang-Nga, Supatra, Sanoamuang, Laorsri (2023): Anthalona vandammei sp. nov. from Thailand, a sibling species of Neotropical Anthalona brandorffi (Sinev & Holwedell, 2002) (Cladocera: Anomopoda: Chydoridae). Zootaxa 5230 (1): 67-78, DOI: https://doi.org/10.11646/zootaxa.5230.1.4

Anthalona vandammei sp. nov. Maiphae, Pholpunthin & Dumont 2008: 34, fig. 2b (Alona verrucosa). Etymology. the species is named after our friend and colleague, prominent Belgian cladocerologist Kay Van Damme. Type locality. Lake Kud-Thing, Bueng Kan province, Thailand, 18° 18.548’ N, 103° 39.700’ E. The type series was collected on 30.01.2017 by A.Y. Sinev & S. Tiang-nga. Samples were collected at a depth of about 0.5 m, where there were dense standing and submerged macrophytes. Holotype. A parthenogenetic female from the type locality, deposited in the Zoological Museum of M. V. Lomonosov Moscow State University, Ml-260. Paratypes. Four parthenogenetic females from the type locality, deposited in the Zoological Museum of M. V. Lomonosov Moscow State University, Ml-261. Other material studied. Five specimens from the type locality were dissected for appendage analyses but not kept; three specimens were used for SEM studies. Description. Parthenogenetic female. In lateral view, body high, egg-shaped (Figs. 1A, 2A–E); maximum height after the middle of the body. Height-length ratio 0.65–0.7 in adults. Dorsal margin convex, posterodorsal and posteroventral angles broadly rounded. Posterior margin convex, ventral margin almost straight, anteroventral angle rounded. Ventral margin (Fig. 1B) with 35–40 setae. About 20 anterior setae short, thin, naked; posterior setae (Fig. 3A–B) long, plumose; distalmost setae located at posteroventral angle of valves. Posteroventral angle (Figs. 1C, 3B) with about 15 short setulae not organized into groups. Carapace and head shield covered by tubercles. Head relatively small, round triangle in side view. In lateral view, rostrum protruding downwards. Ocellus smaller than eye. Distance from tip of rostrum to ocellus slightly greater than that between ocellus and eye. Head shield of typical for genus shape (Figs. 2F, 3D–E), covered by tubercles. Rostrum short, with almost straight anterior margin. Posterior margin rounded. Two main head pores with a narrow connection between them; anterior pore somewhat larger than posterior (Figs. 1D, 3F); PP up to 1 IP. Lateral head pores with bilobed asymmetric cosmaria, located at about 1 IP distance from midline, at level of anterior main head pore. Single posterior dorsal pore (Fig. 3G); minute aperture revealed by SEM examination, located behind posterior margin of head shield. Labrum of moderate size, without lateral projections (Figs. 1E, 3C). Labral keel wide, height only slightly exceeding width, with lateral indentations. Anterior margin of keel convex, with small blunt denticle in the upper third; apex rounded; posterior margin convex, without setulae. Thorax two times longer than abdomen. Dorsal surface of abdominal segments not saddle-shaped. Postabdomen (Figs. 1F–G, 4A–D) short and wide; maximum height at postanal angle. Length about 2.1–2.2 height. Ventral margin straight. Basis of claws separated from distal margin by clear incision. Distal margin weakly convex to straight, distal angle broadly rounded. Dorsal margin weakly convex in postanal portion and unevenly concave in anal one, distal part 1.5–1.7 times longer than preanal one, postanal portion 1.5 times shorter than anal one. Preanal angle well-defined, postanal angle weakly defined. Preanal margin almost straight. Postanal margin with 5–6 narrow denticles, length of denticles decreases posteriorly, length of longest denticles about the width of postabdominal claw base. Anal margin with 3–4 groups of marginal spinules and setulae. Eight–ten lateral groups of setulae. In postanal portion fascicles narrow, composed of 3–8 setulae each, distance fascicles between them about width of fascicle; posteriormost setula very long, thick, with length about 2–2.5 widths of postabdominal claw base. In anal portion fascicles wider and spaced more closely, with shorter distalmost setula. Postabdominal claw slender, of moderate length, shorter than preanal portion of postabdomen. Basal spine short and slender, about 0.25 of the claw length. A long spinule located near the base of basal spine. Antennule (Figs. 1H, 3D) of moderate size, length about 2.5widths, with 3 clusters of short setulae at anterior face. Antennular seta of about 2/3 length of antennule, arising at 1/4 distance from the end. Nine terminal aestetascs, longest of them about half length of antennule. Antenna (Figs. 1I, 3H) with antennal formula: setae 0-0-3/1-1-3 and spines 1-0-1/0-0-1. Basal segment robust, with short seta between branches, branches relatively short, basal segments in both branches 1.5 times longer and thicker than others. Basal and middle segment of endopodite with clusters of short setulae. Seta arising from basal segment of endopodite reaching after the end of endopodite. Seta arising from middle segment of endopodite of similar size to shortest apical setae. One of apical setae on both branches significantly shorter and thinner than two others. Spine on basal segment of exopodite slightly longer than middle segment. Spines on apical segments as long as apical segments. Thoracic limbs: five pairs. Limb I (Figs. 4F, 4G, 5A–C). Epipodite oval, with process two times longer than epipodite itself. Accessory seta 2 times shorter than ODL seta. ODL seta with short setulae in distal portion. IDL with two setae, seta 1 absent, seta 3 thick, curved, as long as ODL seta, ending in one thick and two–three slender long spines, seta 2 short, more thin, bearing 2–3 thick spines; in both setae basalmost spine longer and thicker than two others. Endite 3 with four very short setae, setae 1 and с thick, robust, setae a–b thin. Endite 2 with short seta d, setae e–f of similar length, moderately short, 2.5 times shorter than limb itself. Endite 1 with two long 2-segmented setae of similar size (g–i), setulated in distal part, long flat seta (j) pointed to the limb base. No inner setae found on endites 1–2. Ventral face of limb with 5–6 clusters of long setulae. Two ejector hooks, one of them much larger than other. Limb II subtriangular (Figs. 4G, 5D–E). Exopodite elongated, no exopodite seta found. Eight scraping spines, spines 1–3 largest, armed with thin spinules, setae 4–5 much shorter than setae 1–3, all armed with thin spinules. Spines 6–8 short, with wide bases and short distal part, spine 7 smaller than two others, short denticles observed only on spines 6–7. Distal armature of gnathobase with four elements. Filter plate II with seven setae, three distalmost setae much shorter than others. Limb III. (Fig. 5F–G) Epipodite rounded, with short process. Exopodite narrow, with six setae. Seta 3 longest, setae 4, and 5 about 1/2, 2/3 and 1/5 length of seta 3, setae 1–2 very short. Setae 1–4 plumose, seta 5 armed bilaterally with short hard setulae, seta 6 naked. Distal endite with 3 setae, two distalmost members slender, with blunt tips, without denticles in distal part, short bottle-shaped sensillum located between their bases, seta 3 much shorter, with long setulae. Basal endite with four outer setae (a–d) slightly increasing in length basally. Gnathobase not clearly separated from basal endite. Four inner setae (4–7) very short, slightly increasing in size basally; a sensillum near the base of distalmost seta. Distal armature of gnathobase with four elements, the first one an elongated, cylindrical sensillum; the second a geniculated seta; two others are very short short spines with fused bases. Filter plate with seven setae. Limb IV (Fig. 5H–I). Pre-epipodite setulated. Epipodite with finger-like process two times longer than epipodite itself. Exopodite rounded, with six setae. Seta 1–3 long, of similar length, setae 4–6 about two times shorter. Setae 1–4 flat, plumose, setae 5–6 thin, unilaterally armed with short setulae in distal portion. Inner portion of limb IV with three setae and small sensilla. Scraping seta (1) slender, without denticles in distal portion, first flaming-torch seta (2) wider and longer than other (3). Three soft setae, basalmost seta significantly larger than others. Gnathobase with two-segmented seta and a small hillock distally. Filter plate IV with five setae. Limb V (Fig. 5J). Pre-epipodite setulated, epipodite oval, with process longer than epipodite itself. Exopodite bilobed, with four plumose setae. Seta 1 very long, slightly longer than exopodite body, setae 2, 3 and 4 of about 2/3, 1/2 and 1/3 length of seta 1, respectively. Inner lobe moderately wide, with straight outer margin. At inner face, two short setae, distal seta 1.5 times longer than basal. Filter plate V absent. Ephippial female and male unknown. Size: length of adult female in studied material was 0.31–0.38 mm, height 0.25–0.28 mm. Differential diagnosis. Anthalona vandammei sp. nov. differs from the most species of the genus in IDL setae armed with 3–4 very long spines and in limb II with very shortened distal portion spines 6–8; these characters are shared only by Neotropical A. brandorffi (Sinev & Hollwedel, 2002) and South-East Asian A. spinifera. A. vandammei sp. nov. clearly differs from both A. brandorffi and A. spinifera in IDL seta 3 with basal spine being much thicker and much longer than others, while in spines of IDL seta 3 are of similar thickness and length. A. vandammei sp. nov. differs from A. spinifera in the shape of postabdomen, which is narrowing basally in anal portion, in much longer posterior setae of valves, in posteroventral angle of valves armed with about 15 setulae only, and in having only two flaming-torch setae on limb IV. A. vandammei sp. nov. differs from A. brandorffi in longer setae e–f of limb I and in scraper 7 of limb II being only slightly smaller than scraper 6. Other differences between these two species are summarized in Table 1. Distribution. So far, the new species has been recorded in Lake Kud-Thing in Bueng Kan Province, North-East Thailand, and in Thungtong swamp in Surat Thani Province, Southern Thailand (Maiphae et al. 2008).

Murray-Darling Freshwater Research CentreMDFRC item.1. The hypothesis is tested that large daphnids are able to suppress their own and other species' feeding and reproduction by means of excreting an inhibitory chemical (or chemicals).2. In laboratory experiments with an Australian species, Daphnia carinata, water preconditioned with 3–67 daphnids 1-−1 for 30 h had the effect of reducing feeding rates of D. carinata and D. lumholtzi provided with Selenastrum capricornutum.3. For the two Daphnia species, there were highly significant negative correlations between feeding rate and the preconditioning density of D. carinata.4. Water preconditioned with 20–30 daphnids 1-−1 for 1–2 weeks reduced the grazing rates of Daphnia, Moina, and Diaphanosoma 2–3-fold.5. Moina kept in such water for 2 days stopped feeding. Conditioned water kept for 3 days without animals still inhibited grazing by Moina. Hearing to 100°C removed the inhibitory effect.6. Given excess food, and in non-renewed water, a gradient of D. carinata densities developed a strong negative correlation between clutch size and daphnid density after a 6-day time lag. This result may help explain the direct density-dependent regulation of cladoceran reproduction observed earlier in a subtropical lake.

Pleistocene glaciations had a tremendous impact on the biota across the Palaearctic, resulting in strong phylogeographic signals of range contraction and rapid postglacial recolonization of the deglaciated areas. Here, we explore the diversity patterns and history of two sibling species of passively dispersing taxa typical of temporary ponds, fairy shrimps (Anostraca). We combine mitochondrial (COI) and nuclear (ITS2 and 18S) markers to conduct a range-wide phylogeographic study including 56 populations of Branchinecta ferox and Branchinecta orientalis in the Palaearctic. Specifically, we investigate whether their largely overlapping ranges in Europe resulted from allopatric differentiation in separate glacial refugia followed by a secondary contact and reconstruct their postglacial recolonization from the inhabited refugia. Our results suggest the existence of distinct refugia for the two species, with genetic divergence among intraspecific lineages consistent with late Pleistocene glacial cycles. While B. ferox lineages originated from Mediterranean refugia, the origin of B. orientalis lineages was possibly located on the Pannonian Plain. We showed that most dispersal events predominantly happened within 100 km, coupled with several recent long-distance events (> 1000 km). Hence the regional habitat density of suitable habitats in Central Europe is possibly a key to the co-existence of the two species. Overall, our study illustrates how isolation in combination with stochastic effects linked to glacial periods are important drivers of the allopatric differentiation of Palaearctic taxa.

Analysis of Cladocera (Crustacea: Branchiopoda) subfossil remains in lake sediments features prominently in paleolimnological studies. It is well known, however, that species composition in a taphocoenosis (assemblage of subfossil remains in sediments) does not represent perfectly that of the original living community (biocoenosis) from which it came. We analyzed the representation of different Cladocera skeletal components in sediments of 27 Russian water bodies to compare two methods of enumerating relative abundances of cladoceran remains: (1) recording the number of most abundant fragments of each taxon to represent the number of individuals, and (2) recording each fragment of a taxon as belonging to an individual specimen. Overall, for all cladoceran taxa and all water bodies sampled, proportions of different skeletal components differed from what would be expected based on those in live individuals. Carapaces were the most abundant component in 23 of 27 water bodies. Head shields were common, but predominated in only four samples, whereas postabdomens were rare, accounting for

It is widely accepted among the Cladocera (Crustacea) taxonomists that almost all “cosmopolitan” taxa are represented by some un-revised complexes of cryptic species. But many macro taxa of the cladocerans are still unrevised. The aim of this work is to analyze the taxonomic status of Oriental populations of the genus Bosminopsis Richard, 1895 (Anomopoda: Bosminidae) based on morphological characters. We have studied populations from India, Myanmar, Cambodia, Thailand, Laos, Vietnam, Philippines, Malaysia and Papua New Guinea and concluded that Oriental populations belong to a single species, Bosminopsis africanus (Daday, 1908), initially described from Africa. Analysis of literature data confirms that is widely distributed through whole Oriental zone. A single large mucro, or the mucro accompanied by an additional small spine in both sexes, is the main trait which differentiates B. africanus from B. zernowi Linko, 1901 distributed in more northern regions of Eurasia.

A new species of the genus Pseudochydorus Fryer, 1968 is described from Central Mexico. P. margaritalfonsorum sp. nov. differs from the Old World species of the genus, P. globosus (Baird, 1843) and P. bopingi Sinev, Garibian & Gu, 2016 in the morphology of thoracic limbs I–III. Analysis of existing literature data on distribution and morphology of Pseudochydorus in America suggest than P. margaritalfonsorum sp. nov. is an endemic of Central Mexican Plateau, and at least two more species of the genus are present in other regions of America.

Streptocephalus zeltneri Daday, 1910 Streptocephalus (Streptocephalopsis) zeltneri Daday, 1910a: 396 [Terra typica: Africa centralis, Sudan, Yéliman]. Material examined. Two specimens of Type material (syntypes), one male with broken cercopods and one female, labelled as follows: Yeliman, 1907, F. de Zeltner leg., Muséum National d’Histoire Naturelle, Paris; MNHN-Bp 225 (MNHN-IU-2007-483). Additional examined specimens. All from Senegal. Two males and 13 females from Kédougou, 2.3 km east of Bandafassi, 141 m, 13 º 46′36.66″N 13 º 44′13.02″W, 07-VIII-2015; MNCN 20.04 /20421–20.04/20435. One male and two females also from Kédougou, 2.3 km east of Bandafassi, 161 m, 12 º 32′3.38′′N 12 º 18′32.59′′W, 10-VIII- 2015; MNCN 20.04 /20436–20.04/20438. One individual from Kédougou, Bandafassi, 141 m, 12 º 32′21.13″N 12 º 17′20.89″W, 10-VIII-2015; MNCN 20.04 /20439 (Table 2). Published records. Mali: Goumbou (Hamer et al. 1994b; Maeda-Martínez et al. 1995b); Yéliman (Hamer et al. 1994b; Belk & Brtek 1997). Senegal: pool at Ndilla dam, close to Linguère (Monod 1969; Hamer et al. 1994b); Palagu (Maeda-Martínez et al. 1995b). Geographic distribution. This species is only known from Mali and Senegal (Monod 1969; Hamer et al. 1994b; Maeda-Martínez et al. 1995b; Belk & Brtek 1997). Records from Sudan (Hamer et al. 1994b; MaedaMartínez et al. 1995b) are currently located in Mali. The previously recorded populations of S. zeltneri in Senegal need revision (see comments on the geographic distribution account of S. wolof). Remarks. According to the literature, Streptocephalus zeltneri is morphologically similar to S. trifidus Hartland-Rowe, 1969 and S. bouvieri Daday 1910 (Daday 1910a; Hartland-Rowe 1969; Hamer et al. 1994b). In their revision, Maeda-Martínez et al. (1995b) included S. zeltneri in a species group formed by S. bouvieri, S. gauthieri, S. rothschildi and S. spinifer. A more detailed study including morphological and molecular characters would be desirable to unveil the evolutionary relationships among the species of the bouvieri species group sensu Maeda-Martínez et al. (1995b). Brendonck & Coomans (1994) provided a description and a picture of the eggs of the holotype of S. zeltneri, stating that the eggs have simple and more or less regular polygons, and that their ribs are unkeeled. Similarly, the eggs from our samples of S. zeltneri of southeastern Senegal, have unkeeled ribs (Fig. 3B). This trait was consistent in the revised populations of S. zeltneri with mature females (two out of the three populations). Specimens were found in small and transparent pools with clam shrimps. Live specimens present the cercopods and the brood pouch with a strong red coloration., Published as part of Sainz-Escudero, Lucía, Alonso, Miguel & Sánchez-Vialas, Alberto, 2022, Diversity and distribution of Anostraca in temporary ponds in Western Africa with description of a new species of Streptocephalus Baird, 1852 (Pancrustacea: Branchiopoda: Streptocephalidae), pp. 388-412 in Zootaxa 5213 (4) on pages 404-405, DOI: 10.11646/zootaxa.5213.4.4, http://zenodo.org/record/7381453, {"references":["Daday, E. V. (1910 a) Monographie systematique des Phyllopodes Anostraces. Annales des Sciences Naturelles, Zoologie, Series 9, 11, 91 - 489.","Hamer, M., Brendonck, L., Coomans, A. & Appleton, C. (1994 b) A review of the African Streptocephalidae (Crustacea: Branchiopoda: Anostraca) Part 2: north of Zambezi and Kunene rivers. Archiv fur Hydrobiologie, 99, 279 - 311.","Maeda-Martinez, A. M., Belk, D., Obregon-Barboza, H. & Dumont, H. J. (1995 b) A contribution to the systematics of the Streptocephalidae (Branchiopoda: Anostraca). Hydrobiologia, 298, 203 - 232. https: // doi. org / 10.1007 / 978 - 94 - 011 - 0291 - 9 _ 19","Belk, D. & Brtek, J. (1997) Supplement to \" Checklist of the Anostraca \". Hydrobiologia, 359 (1 - 3), 243 - 245. https: // doi. org / 10.1023 / A: 1003172516989","Monod, T. (1969) Contribution a l'etude des eaux douces de l'Ennedi IV. Crustaces Phyllopodes. Bulletin de l'Institut Francais d'Afrique Noire, 31, 500 - 523.","Hartland-Rowe, R. (1969) A new species of Streptocephalus (Anostraca) from Rhodesia. Crustaceana, 16 (1), 78 - 80. https: // doi. org / 10.1163 / 156854068 X 00205","Brendonck, L. & Coomans, A. (1994) Egg morphology in African Streptocephalidae (Crustacea: Branchiopoda: Anostraca) Part 2: North of Zambezi and Kunene rivers, and Madagascar. Archiv fur Hydrobiologie, 99 (3), 335 - 356."]}

Streptocephalus wolof sp. nov. (Figs. 6–9) Etymology. The name wolof refers to the ethnic group native to Senegal, Gambia, and in a lesser extent, to Mauritania. Most of the known geographic range of the newly described species overlaps with the Wolof ethnic distribution. The name is a noun in genitive case. Type material. Holotype. Male: Senegal, Tambacounda, 6 km west of Koutenabe, 93 m, 14 º 15′34.38″N, 12 º 35′42.38″W, 16-VIII-2015 (white label, printed); MNCN 20.04 /20321 (white label, printed); Holotypus, Streptocephalus wolof Sainz-Escudero, Alonso & Sánchez-Vialas, des. 2022 (white label printed). Paratypes. 20males, 15 females: Senegal, Saint-Louis, 2 km north of Podor, 9 m, 16 º 40′17.43″N, 14 º 57′55.29″W, 18-VIII-2015 (white label, printed); MNCN 20.04 /20269–20.04/20289 and 20.04/20327–20.04/20340 (white label, printed). Twenty-six males, 50 females: Senegal, Ziguinchor, Diembéreng, 9 m, 12 º 28′00.61″N, 16 º 47′02.16″W, 13-VIII-2015 (white label, printed); MNCN 20.04 /20290–20.04/20302 and 20.04/20341–20.04/20403 (white label, printed). Thirteen males, 22 females: Senegal, Matam, 1.9 km south-east of Bokiladji, 30 m, 15 º 02′48.91″N, 12 º 43′49.78″W, 17-VIII-2015 (white label, printed); MNCN 20.04 /20303–20.04/20320 and 20.04/20404- 20.04/20420(white label,printed). Five males: Senegal, Tambacounda, 6km west of Koutenabe, 93 m, 14 º 15′34.38″N, 12 º 35′42.38″W, 16-VIII-2015 (white label, printed); MNCN 20.04 /20321–20.04/20326 (white label, printed). All paratypes labelled: “ Paratypus, Streptocephalus wolof Sainz-Escudero, Alonso & Sánchez-Vialas, des. 2022 (white label printed) (Table 2). Description. Male. Head (Fig. 6A) round. Nuchal organ visible. Eyes spherical with diameter as long as its corresponding eyestalk. First antennae filiform, 2 times longer than basal joint of second antenna (Fig. 6A). Distal end with 3 subdistal setae, approximately 2–2.5 times longer than antennular thickness (Fig. 6B). Frontal appendage (Fig. 6C) consisting of 2 slightly curved long and pointed branches, reaching half-length of distal antennomere, with 2 small tips at inner margin, one close to base and other approximately in its half. Single acute basal projection in its ventral surface, whose length is about one-third of the latter. Second antennae (Fig. 6D) reaching thoracopod IX or X when extending backwards. Proximal and distal antennomeres subcylindrical, similar in length, 2 times as long as broad. Inner longitudinal row of 12 or 13 small papillae (sp) from medial part of proximal antennomere to medial part of distal antennomere. Medial part of distal antennomere with transversal row of 5–7 small papillae. Small papillae consist of a conical base with 1 apical small sensory seta. Apical joint (aj) oriented ventrolaterally, at distal end of basal joint, approximately as long as distal antennomere. Hand (according to Maeda-Martínez et al. 1995b) with 2 sharp and smooth rami. Longest ramus (anterior primary ramus, “thumb) 2 times longer than distal antennomere, slightly curved at end of proximal third; small subtriangular blunt (spur) present in its proximal part. Shorter ramus (posterior ramus, “finger) 0.6 times of anterior primary ramus length, and dorsally bent; proximal part with a small rounded protruding structure followed by short thickening. Labrum (Fig. 6E) subtrapezoidal, without distal protuberances; terminal fleshy process straight, tapering distally. Two setulose pads placed ventrally midway and in the base of fleshy process. Phyllopodia with gross structure, typical of the genus (Figs. 7A–E). Eleven pairs of thoracopods. First thoracopod (Fig. 7A) 2 times shorter than seventh thoracopod (Fig. 7C); eleventh thoracopod (Fig. 7E) 0.8 times longer than seventh thoracopod; rest of thoracopods subsimilar in size. Praepipodite (PE) oval, with serrated outline in all thoracopods. Epipodite (EP) wide, with undulated margin (Figs. 7A, C) in the tenth anterior thoracopod; eleventh thoracopod epipodite elongated, with serrated extreme (Fig. 7E). Exopodite (EX) oval, bordered by plumose marginal setae; first thoracopod small (Fig. 7A), not sticking out from endopodite; rest of thoracopods (Figs. 7C, E) of similar size to endopodite. Endopodite (EN) broad, covered by short plumose setae in its outer margin, and provided with a more or less marked depression in the middle (Figs. 7A, C, E). Endites from first to tenth thoracopods: first endite with 2 submarginal spine-like setae on anterior surface, proximal one long and thin, provided with denticles, and distal one shorter, spiniform, with a basal tiny spine-like seta (Figs. 7A, C); second endite with a long spiniform proximal seta, submarginal on anterior surface, with a basal tiny seta (Figs. 7A, C); third endite with 2 unequal submarginal spinelike seta on anterior surface and three plumose setae on posterior surface (Figs. 7B, D); 4 endite with 2 unequal submarginal spinelike seta on anterior surface and 2 plumose setae on posterior surface (Figs. 7B, D); fifth endite with 3 unequal submarginal spinelike seta on anterior surface and 2 plumose setae on posterior surface (Figs. 7B, D). Endites to eleventh thoracopod (Fig. 7E): first endite with submarginal spine-like setae very reduced; second endite with 2 small spines on anterior surface and 3 plumose setae on posterior surface; third and fourth endites with 2 small spines in anterior surface and 2 plumose setae on posterior surface; fifth endite with 1 small spine in anterior surface and 2 plumose setae on posterior surface. Abdominal segments (Fig. 8A) typical of the genus. First, second, and third segments with 2 small cuticle projections, one at each side, close to posterior margin (pointed with arrow in Fig. 8A). Genital segments (Fig. 8B) slightly expanded and partially fused. First segment ventrally smooth. Second segment with linguiform outgrowths 2 times shorter than basal part of gonopods, placed posterolaterally on ventral surface. Basal part of gonopods non-retractile, reaching the end of third abdominal segment; spinulated appendix located in its basal inner side and 2 rounded expansions in its distal end. Everted part of gonopods twice longer than basal part, provided with longitudinal rows of spines. Cercopods (Fig. 8C) of the type “spinose cercopods sensu Maeda-Martínez (1995b), sclerotized, with short spine-like setae replacing the marginal plumose setae on the distal half. Cercopods as long as the last 4 abdominal segments. Anus terminal. Female. First antennae (Fig. 9A) filiform 4 times longer than eye diameter, and 2 and a half longer than second antenna. Distal end as in male. Second antennae (Fig. 9A) broad with rounded end, little longer than eye plus stalk. Distal surface and margins bearing short setae. One small marginal beak on anterior edge close to distal end. Thoracopods as in male. Abdominal segments (Fig. 9C) with smooth surface. Some of them bearing warty outgrowths provided with sensillae (in fourth and sixth segments in the figure). Genital segments (Fig. 9C) completely fused. Brood pouch elongate, fusiform extending to middle of fourth abdominal segment; end provided with an angular flat expansion directed posteriorly (Fig. 9D). Eggs subspherical; surface covered by wide protruding keeled ribs delimiting polygonal fields (Fig. 3A). Diameter around 200 µm. Cercopods (Fig. 9E) broad in the base, margined on both sides by feathery setae gradually shortening to their acute end. Length as last four abdominal segments plus telson. Size. Total body length of the holotype (MNCN 20.04/20321), (including cercopods setae): 7.48 mm. Largest female specimen recorded: 10.56 mm. Geographic distribution. Streptocephalus wolof is known from the following localities in Senegal: 2 km north of Podor, Diembéreng, 1.9 km south-east of Bokiladji, 6 km east of Koutenable and Diabal (Table 2). Future studies could likely extend its distribution to the neighboring countries Mauritania, Gambia, Mali, Guinea, and Guinea-Bissau. The previous recorded populations identified as S. zeltneri in Senegal [Lingure and Palagu (Monod 1969; Hamer et al. 1994b; Maeda-Martínez et al. 1995b)] require revision as they were not examined by us, and therefore, we were unable to confirm its taxonomic identity. However, we tentatively treated these records as S. zeltneri until additional studies confirm its identity (Fig. 1). Remarks. The new species is closely related to Streptocephalus zeltneri. Both species cannot be distinguished based on adult morphological characters, and consequently they can be considered as cryptic species (Marrone et al. 2017). However, they differ on the basis of the eggs macrosculpture. Eggs of S. wolof present their surface covered with carinated ribs, delimiting polygons of variable number of sides (Fig. 3A). This trait was consistent in each revised population that contained mature females. Streptocephalus wolof is the most commonly found and widespread Anostraca species in Senegal, occurring in several ecoregions (including the Sahelian and Sudanian savannas, and the Guinean forest savanna close to the Guinean forest) (Fig. 1). The studied specimens of S. wolof were found during the rainy season in temporary ponds, both with transparent and turbid waters, often in syntopy with amphibian larvae, as Sclerophrys xeros (Tandy, Tandy, Keith & Duff-MacKay, 1976), Kassina senegalensis (Duméril & Bibron, 1841), K. fusca Schiøtz, 1967, Ptychadena bibroni (Hallowell, 1845), and Phrynobatrachus francisci Boulenger, 1912 (Fig. 5)., Published as part of Sainz-Escudero, Lucía, Alonso, Miguel & Sánchez-Vialas, Alberto, 2022, Diversity and distribution of Anostraca in temporary ponds in Western Africa with description of a new species of Streptocephalus Baird, 1852 (Pancrustacea: Branchiopoda: Streptocephalidae), pp. 388-412 in Zootaxa 5213 (4) on pages 397-399, DOI: 10.11646/zootaxa.5213.4.4, http://zenodo.org/record/7381453, {"references":["Maeda-Martinez, A. M., Belk, D., Obregon-Barboza, H. & Dumont, H. J. (1995 b) A contribution to the systematics of the Streptocephalidae (Branchiopoda: Anostraca). Hydrobiologia, 298, 203 - 232. https: // doi. org / 10.1007 / 978 - 94 - 011 - 0291 - 9 _ 19","Monod, T. (1969) Contribution a l'etude des eaux douces de l'Ennedi IV. Crustaces Phyllopodes. Bulletin de l'Institut Francais d'Afrique Noire, 31, 500 - 523.","Hamer, M., Brendonck, L., Coomans, A. & Appleton, C. (1994 b) A review of the African Streptocephalidae (Crustacea: Branchiopoda: Anostraca) Part 2: north of Zambezi and Kunene rivers. Archiv fur Hydrobiologie, 99, 279 - 311.","Marrone, F., Rogers, D. C., Zarattini, P. & Naselli-Flores, L. (2017) New challenges in anistracan research: old issues, new perspectives and hot topics. Hydrobiologia, 801, 179 - 185. https: // doi. org / 10.1007 / s 10750 - 017 - 3345 - 6","Tandy, M., Tandy, J., Keith R. & Duff-MacKay, A. (1976) A new species of Bufo (Anura: Bufonidae) from Africa's dry savannas. Pearce-Sellards Series, Texas Memorial Museum, Austin, 24, 1 - 20.","Dumeril, A. M. C. & Bibron G. (1841) Erpetologie Generale ou Histoire Naturelle Complete des Reptiles. Vol. 8. Enclyclopdique Roret, Paris, 792 pp.","Schiotz, A. (1967) The treefrogs (Rhacophoridae) of West Africa. Spolia Zoologica Musei Hauniensis, KObenhavn, 25, 1 - 346.","Hallowell, E. (1845) Descriptions of new species of African reptiles. Proceedings of the Academy of Natural Sciences of Philadelphia, 2, 247 - 250.","Boulenger, G. A. (1912) Descriptions of new African batrachians preserved in the British Museum. Annals and Magazine of Natural History, Series 8, 10, 140 - 142. https: // doi. org / 10.1080 / 00222931208693207"]}

Streptocephalus sudanicus Daday, 1910 Streptocephalus sudanicus Daday, 1910b: 261 [Terra typica: Sudan, Nioro. Types at the Museum National d’Histoire Naturelle, Paris, and (6942) at the Zoological Institute of the Academy of Sciences (Saint Petersburg, Russia); Belk & Brtek 1995]. Material examined. Six males, seven females from Senegal: Tambacounda, Gourel Yoba, 39 m, 13º25′04.62″N 13 º 24′30.23″W, 11-VIII-2015; MNCN 20.04 /20440–20.04/20452. One male from Senegal: Tambacounda, Diabal, 56 m, 14 º 45′37.66″N 12 º 26′06.66″W, 16-VIII-2015; MNCN 20.04 /20453 (Table 2). Published records. Burkina Fasso: Arbolle, Nion (Maeda-Martínez et al. 1995b). Mali: Nioro du Sahel (Brendock et al. 1992; Belk & Brtek 1997); Yéliman (Belk & Brtek 1997); Goumbou (Belk & Brtek 1997). Niger: Chad-Niger región; Margdi (Brendock et al. 1992). Nigeria: Tofa E of Kabo (Maeda-Martínez et al. 1995b). Senegal: pond in Ndilla, close to Linguère (Monod 1969; Brendock et al. 1992); Palagu (Maeda-Martínez et al. 1995b). Sudan: Kas, E Nyalal lake (Maeda-Martínez et al. 1995b); Geographic distribution. Burkina Faso, Mali, Niger, Senegal, Sudan. Some localities reported from Sudan (Brendock et al. 1992) are actually located in Mali. Remarks. Brendock et al. (1992) noted the singularities of Streptocephalus sudanicus based on the presence of spinules on the finger dorsal side and the existence of tetrahedral eggs (Fig. 3C). They also created a new taxon, the subgenus Parastreptocephalus, based on these characters. Other species included in this taxon are S. lamellifer Thiele, 1900, S. kaokoensis Barnard, 1929, and S. zuluensis Brendonck & Hamer, 1992 (Brendock et al. 1992). The studied pecimens of S. sudanicus were found in pools with turbid water. Live specimens present the cercopods with a marked red coloration., Published as part of Sainz-Escudero, Lucía, Alonso, Miguel & Sánchez-Vialas, Alberto, 2022, Diversity and distribution of Anostraca in temporary ponds in Western Africa with description of a new species of Streptocephalus Baird, 1852 (Pancrustacea: Branchiopoda: Streptocephalidae), pp. 388-412 in Zootaxa 5213 (4) on page 405, DOI: 10.11646/zootaxa.5213.4.4, http://zenodo.org/record/7381453, {"references":["Daday, E. V. (1910 b) Quelques Phyllopodes Anostraces. Nouveaux. Appendice a la Monographie Systematique des Phyllopodes Anostraces avec 5 figures dans le texte. Annales des Sciences Naturelles, Zoologie, Series 9, 12, 241 - 264.","Belk, D. & Brtek, J. (1995) Checklist of the Anostraca. Hydrobiologia, 298, 315 - 353. https: // doi. org / 10.1007 / BF 00033826","Maeda-Martinez, A. M., Belk, D., Obregon-Barboza, H. & Dumont, H. J. (1995 b) A contribution to the systematics of the Streptocephalidae (Branchiopoda: Anostraca). Hydrobiologia, 298, 203 - 232. https: // doi. org / 10.1007 / 978 - 94 - 011 - 0291 - 9 _ 19","Belk, D. & Brtek, J. (1997) Supplement to \" Checklist of the Anostraca \". Hydrobiologia, 359 (1 - 3), 243 - 245. https: // doi. org / 10.1023 / A: 1003172516989","Monod, T. (1969) Contribution a l'etude des eaux douces de l'Ennedi IV. Crustaces Phyllopodes. Bulletin de l'Institut Francais d'Afrique Noire, 31, 500 - 523.","Thiele, J. (1900) Uber eine von Herrn O. Neumann gefundene Phyllopoden-art. Zoologischen Jahrbuchen: Abtheilung fur Systematik Geographie und Biologie der Thiere, 20, 371 - 374.","Barnard, K. H. (1929) Contributions to the Crustacean fauna of South Africa. 10. A revision of Branchiopoda (Phyllopoda). Annals of the South African Museum, 29, 181 - 270.","Brendonck, L., Hamer, M. & Thiery, A. (1992) Occurrence of tetrahedral eggs in the Streptocephalidae Daday (Branchiopoda: Anostraca) with descriptions of a new subgenus, Parastreptocephalus, and a new species, Streptocephalus (Parastreptocephalus) zuluensis Brendonck and Hamer. Journal of Crustacean Biology, 12 (2), 282 - 297. https: // doi. org / 10.2307 / 1549081"]}

Three genera of Anostraca have been recorded so far in Senegal: Streptocephalus Baird, 1852, Branchinella Sayce, 1903 and Artemia Leach, 1819. The occurrence of the previously recorded freshwater species in Senegal have been confirmed in this work, namely Streptocephalus zeltneri Daday, 1910, S. sudanicus Daday, 1910 and Branchinella (Branchinellites) chudeaui (Daday, 1910). New records and the description of a new species are given. The new species, Streptocephalus wolof sp. nov., has been recognized through molecular (mitochondrial and nuclear markers) and morphological (egg shape) data. The adult stage of this new species is morphologically indistinguishable to its closely related species Streptocephalus zeltneri, suggesting the existence of two cryptic species in Senegal. Finally, some taxonomic comments on the genus Streptocephalus are presented.

Branchinella (Branchinellites) chudeaui (Daday, 1910) Branchinellites chudeaui Daday, 1910b: 256 [Terra typica: Bassin du Moyen Niger, Simbidissi. Syntypes at the Muséum National d’Histoire Naturelle, Paris (Linder, 1941) and D1912-93, I/A-73 at the Hungarian Natural History Museum, Budapest; Belk & Brtek 1995]. Branchinella chudeaui (Daday, 1910): Linder 1941: 270. Material examined. Seven males, 23 females, from Senegal: Matam, Tilagne Tokkosel, 31 m, 15 º 58′13.40″N 13 º 36′48.42″W, 17-VIII-2015; MNCN 20.04 /20454–20.04/20483. Five males, from Senegal: Matam, Tilagne Tokkosel, 31 m, 15 º 58′12.13″N 13 º 36′39.27″W, 17-VIII-2015; MNCN 20.04 /20484–20.04/20488. Fifty-seven individuals, not sexed, Senegal: Matam, Tilagne Tokkosel, 31 m, 15 º 58′13.40″N 13 º 36′48.42″W, 17-VIII-2015; MNCN 20.04 /20489–20.04/20545 (Table 2). Published records. Chad: “Guelta de Koub Basso, mountain massif of Ennedi (Monod 1969). Mali-Niger: Bassin du Moyen-Niger, Simbidissi (Daday1910b). Senegal: Ndilla, close to Linguère (Monod 1969); Tambacounda, Poull Koz, 40 or 50 km northeast from the oriental edge of British Gambia (Gauthier 1951); Tambacounda, Poull Bourgou, in the forest savanna that extends to southwest of Tambacounda (Gauthier 1951). Geographic distribution. Reported from Chad, Gambia, Mali-Niger and Senegal (Daday 1910b; Gauthier 1951; Monod 1969; Belk & Brtek 1995, 1997; Rogers et al. 2013). Remarks. The type locality of this species is currently dubious, as “Bassin du Moyen-Niger, Simbidissi could be either in Mali or Niger. Branchinella chudeaui was described within Branchinellites on the basis of gonopodal traits, which are lacking in Branchinella s. str (Daday 1910b; Rogers 2006; Rogers et al. 2013)., Published as part of Sainz-Escudero, Lucía, Alonso, Miguel & Sánchez-Vialas, Alberto, 2022, Diversity and distribution of Anostraca in temporary ponds in Western Africa with description of a new species of Streptocephalus Baird, 1852 (Pancrustacea: Branchiopoda: Streptocephalidae), pp. 388-412 in Zootaxa 5213 (4) on pages 405-406, DOI: 10.11646/zootaxa.5213.4.4, http://zenodo.org/record/7381453, {"references":["Daday, E. V. (1910 b) Quelques Phyllopodes Anostraces. Nouveaux. Appendice a la Monographie Systematique des Phyllopodes Anostraces avec 5 figures dans le texte. Annales des Sciences Naturelles, Zoologie, Series 9, 12, 241 - 264.","Linder, F. (1941) Contributions to the morphology and the taxonomy of the Branchiopoda Anostraca. Zoologiska Bidrag fran Uppsala, 20, 101 - 303.","Belk, D. & Brtek, J. (1995) Checklist of the Anostraca. Hydrobiologia, 298, 315 - 353. https: // doi. org / 10.1007 / BF 00033826","Monod, T. (1969) Contribution a l'etude des eaux douces de l'Ennedi IV. Crustaces Phyllopodes. Bulletin de l'Institut Francais d'Afrique Noire, 31, 500 - 523.","Gauthier, H. (1951) Contribution l'etude de la faune des eaux douces au Senegal (Entomostraces). Imprimerie Minerva, Alger, 169 pp.","Belk, D. & Brtek, J. (1997) Supplement to \" Checklist of the Anostraca \". Hydrobiologia, 359 (1 - 3), 243 - 245. https: // doi. org / 10.1023 / A: 1003172516989","Rogers, D. C., Shu, S. & Yang, J. (2013) The identity of Branchinella yunnanensis Shen, 1949, with a brief review of the subgenus Branchinellites (Branchiopoda: Anostraca: Thamnocephalidae). Journal of Crustacean Biology, 33 (4), 576 - 581. https: // doi. org / 10.1163 / 1937240 X- 00002155","Rogers, D. C. (2006) A genus level revision of the Thamnocephalidae (Crustacea: Branchiopoda: Anostraca). Zootaxa, 1260 (1), 1 - 25. https: // doi. org / 10.11646 / zootaxa. 1260.1.1"]}

Sinev, Artem Y., Dadykin, Ivan A. (2022): Notes on morphology and ecology of an elusive water flea Rhynchotalona latens (Sarmaja-Korjonen, Hakojärvi & Korhola, 2000) (Crustacea: Cladocera). Zootaxa 5200 (3): 260-270, DOI: https://doi.org/10.11646/zootaxa.5200.3.4

Here we report the complete mitochondrial genome of the Arctic fairy shrimp, Branchinecta paludosa (Müller, 1788) (Anostraca, Branchinectidae), which was collected in the High Arctic of North Greenland. A complete 16,059 bp mitochondrion of B. paludosa was sequenced and assembled with the Illumina next generation sequencing platform. The B. paludosa mitogenome contains 13 PCGs, 22 tRNAs and 2 rRNA genes that are commonly observed in most metazoans and shows the conserved gene arrangement pattern of Anostraca. Our results of the phylogenomic analysis are consistent with the previous phylogenetic relationship, based on nuclear 18S ribosomal DNA. The B. paludosa mitogenome will be useful for understanding the geographical distribution and phylogenetic relationship of anostracans.

Rhynchotalona latens (Sarmaja-Korjonen, Hakojärvi et Korhola, 2000) Sarmaja-Korjonen et al., 2000: 166–167, Fig. 2 (Unapertura); Van Damme & Nevalainen, 2019: 465–466, Fig. 1–3; Korovchinsky et al., 2021: 386, Fig. 117:10–13. Description. Parthenogentic female. Body oval in lateral view, low in juveniles (Figs. 1A,B), of moderate height in adults (Figs. 1C,D, 2A–F); maximum height at body middle or behind it; body moderately compressed laterally. Height-length ratio about 0.6 in adults. Dorsal margin strongly convex, postero-dorsal and postero-ventral angles broadly rounded. Posterior margin strongly convex, ventral margin almost straight, antero-ventral angle rounded. Ventral margin (Fig. 1E) with about 40 setae; about 10–15 anterior setae moderately long, 5–7 middle setae very short, posterior 20 setae (Figs. 3E–F) very long, longer than setae of anterior group, posteriormost setae in the group being longest, located at postero-ventral angle. Postero-ventral angle (Fig. 1F) without denticles, with 15–20 moderately long setulae not reaching to the margin of the valves. A row of about 100 very short setulae along posterior margin on inner side of carapace. Sculpture of valves variable, with well or weakly developed longitudinal lines (Figs. 2A–C, F), or with tubercles (Figs. 2D,E). Unlike most Aloninae, adult female always bears a single parthenogenetic egg in the brood chamber; length of the egg slightly less than half-length of specimen. Head relatively small, triangular in lateral view. In lateral view rostrum moderately long, about two lengths of antennule, weakly curved posteriorly. Ocellus smaller than eye. Distance from tip of rostrum to ocellus about 2–2.5 times of that between ocellus and eye. Head shield with shape typical for the alonines, with maximum width behind maxillar articulation, smooth in specimens with linear sculpture of valves, tuberculated in specimens with tuberculated valves. Rostrum elongated, narrow triangular in dorsal view, with rounded tip (Figs. 1G, 3A). Posterior margin of head shield rounded (Figs. 4A,B). Main head pore (Figs. 4A,B) as oval rimmed field; distance from pore to the posterior end of head shield slightly greater than pore length. Lateral head pores minute, located at about two lengths of main head pore from midline, at the level of anterior margin of main head pore. Labrum (Figs. 1H–J) small, without lateral projections. Labral keel of narrow, height about 2 times width. Anterior margin of keel evenly convex, apex broadly rounded, posterior margin weakly convex, without clusters of setules. Thorax two times longer than abdomen. Dorsal surface of abdominal segments not saddle-shaped. Postabdomen short and narrow, with almost parallel margins (Figs. 1K, 4C–E). Distal angle obtuse, rounded. Dorsal margin with anal portion longer than postanal one. Preanal and postanal angles weakly defined. Preanal margin without notches. Postanal margin with 5–6 large single marginal denticles, length of largest of them 1.5 greater than width of postabdominal claw base. Anal margin with 2–3 groups of small spinules. Postanal part with about 3–4 well-developed lateral fascicles of 3–6 thick setules, shorter than marginal denticles; in anal portion 4–5 groups of 7–15 thinner, shorter setulae. Postabdominal claw (Figs. 1L, 4F) weakly curved, shorter than preanal portion of postabdomen. Basal spine short, slightly curved, about 0.15–0.2 length of claw. Antennule long, truncated at the end (Figs. 1M, 3B). Antennular sensory seta slender, about half length of antennule, arising at 2/3 distance from the base. Nine terminal aesthetascs, two longest only slightly shorter than antennule. Antenna of moderate length (Figs. 3C,D, 5A), antennal formula: setae 0-0-3/0-0-2; spines 1-0-1/0-0-1. Basipodite robust, with small seta between branches. Branches with segments of similar length. Spine on basal segment of exopodite about 1/3 length of middle segment. Spine on apical segment of endopodite significantly longer than apical segment. Spine on apical segment of exopodite as long as apical segment. One seta on apical segment of exopodite two times shorter and thinner than two others; longer setae on apical segment of exopodite of similar length and thickness than apical setae of endopodite. Thoracic limbs: six pairs. Limb I (Figs. 5B–C). Epipodite rounded, with a process 2–2.5 times longer than epipodite itself. Accessory seta moderately long, two times shorter than ODL single seta. IDL with two setae, seta 1 not found, setae 2 and 3 moderately thick, armed distally with thin setules, seta 2 slightly shorter than ODL seta, seta 3 slightly longer than ODL seta. Setae of endite 3 increasing in length from behind; seta c of same morphology as setae e–f of endite 2. Inner seta (2) on endite 2 not found; seta b much shorter than setae e–f; setae e and f of similar length, two times shorter than limb itself. Endite 1 with short inner seta (3), two two-segmented setae (g–h) and a short flat seta (i). Ventral face of limb with 5–6 clusters of setae. Maxillar process short, with a single seta. Limb II (Figs. 5D,E). Exopodite elongated, with a long seta. Eight scraping spines decreasing in length proximally, armed with thin setules. Distal armature of gnathobase with four elements. Filter plate with seven setae, posteriormost seta remarkably shorter than others. Limb III (Figs. 5F,G). Epipodite without a process. Exopodite subquadrangular, with seven setae. Setae 1–5 plumose, setae 6–7 slender, thin, without long setules. Seta 3 being longest, seta 6 slightly shorter than seta 3, setae 1, 4 and 7 about half length of seta 3, setae 2 and 5 of 1/4 and 1/3 length of seta 3 respectively. Distal endite with three long setae, two distal setae (1–2) long and thin adapted for scraping, small sensillum (s) located between their bases, seta 3 flattened, with long setules. Basal endite with four stiff setae (a–d) of similar size. Four soft setae increasing in size proximally, small sensillum near the base of distalmost seta. Distal armature of gnathobase with four elements: an elongated, cylindrical sensillum; large geniculated seta; and two spines with fused bases. Filter plate of seven setae. Limb IV (Figs. 5H,I). Pre-epipodite setulated; epipodite with a process longer than epipodite itself. Exopodite subrectangular, with six setae Setae 1–4 flattened, plumose, setae 5–6 slender, thin, naked. Seta 1 being longest, setae 2–3 slightly shorter thans seta 1, seta 4 about 1/3 length of seta 1, setae 5–6 about 2/3 length of seta 1. Inner portion of limb IV with four setae and small elongated sensillum (s) (see Fig. 5I). Scraping seta (1) moderately long, three flaming-torch setae elongated, of similar length, first of them (2) armed with long, thick setulae, two other—with short thin setulae. Three soft setae (a–c) increasing in length basally. Gnathobase with two-segmented seta and a small hillock distally. Filter plate with five setae. Limb V (Figs. 5J,K). Pre-epipodite setulated. Epipodite with a process longer than epipodite itself. Exopodite clearly bilobed of moderate size, with four plumose setae decreasing in length basally; seta 4 about half length of seta 1. Inner limb portion as elongated oval lobe with setulated inner margin. At inner face, two short setae of similar length. Filter plate with three small setae and a large triangular sensillum (s). Limb VI as oval setulated lobe (Fig. 5L). Ephippial female and male unknown. Size. Single found juvenile female of instar I length 0.21 mm, height 0.11 mm Juvenile females of instar II length 0.26–0.27 mm, height 0.14–0.15 mm. Adult parthenogenetic female length 0.27–0.33 mm, height 0.17–0.2 mm. Differential diаgnosis. Rhynchotalona latens differs from all other species of the genus in shape of head shield, which has a broadly rounded posterior angle, and in lateral pores located at significant distance from midline. All other species of the genus (see Røen 1973; Sinev & Kotov 2014) have the posterior portion of the head shield as a broad elongated protrusion with rounded tip, and lateral head pores located very close to the main pore. Habitually, R. latens is most similar to Greenland endemic R. kistarae Røen, 1973, these species differ in shape of the main head pores, which is elongated in R. kistarae. R. latens clearly differs from species of falcata -clade (R. falcata (Sars. 1862), R. weiri Sinev & Kotov, 2014, and R. longiseta Sinev & Kotov, 2014) in rounded anteroventral corner of valves and armament of the postabdomen. In species of the falcata -clade the anteroventral corner of the valves forms an elongated protrusion with rounded tip (Sinev & Kotov 2014). Other differences between R. latens, R. kistarae and species of the falcata -clade are summarized in Table 1. Distribution and ecology. Recent findings belong to Finland, North Karelia and Pechora River Delta. This is an interstitial species, dwelling within patches of the waterlogged Sphagnum mosses at lakes shores; some specimens are accidentally found in littoral zone of such lakes. Water conditions measurements, taken on 26 June 2022 at Krugloe Lake, reveal significant differences between littoral zone of the lake and the patches of Sphagnum mosses. Water squeezed from Sphagnum had a temperature 24.9°C, pH 3.4, oxygen concentration 3.4 mg /l (saturation 41%) and conductivity 34.1 µS/cm, while littoral lake water at 10–15 cm from the coast had temperature 22.1°C, pH 5.3, oxygen concentration 8.8 mg /l (saturation 100%), and conductivity 24 µS/cm. In the studied material, only parthenogenetic females were present from late June to the middle of September. R. latens seems to be a slow and rather reluctant swimmer; observed specimens swim rather slow, unsteady, and for short periods, usually less than 10–15 seconds, preferring crawling on substrate using antennae and postabdomen., Published as part of Sinev, Artem Y. & Dadykin, Ivan A., 2022, Notes on morphology and ecology of an elusive water flea Rhynchotalona latens (Sarmaja-Korjonen, Hakojärvi & Korhola, 2000) (Crustacea: Cladocera), pp. 260-270 in Zootaxa 5200 (3) on pages 261-267, DOI: 10.11646/zootaxa.5200.3.4, http://zenodo.org/record/7260518, {"references":["Sarmaja-Korjonen, K., Hakojarvi, M. & Korhola, A. (2000) Subfossil remains of an unknown chydorid (Anomopoda: Chydoridae) from Finland. Hydrobiologia, 436, 165 - 169. https: // doi. org / 10.1023 / A: 1026502219867","Van Damme, K. & Nevalainen, R. L. (2019) The most latent cladoceran in the Holarctic revealed - sinking Unapertura Sarmaja-Korjonen, Hakojarvi & Korhola, 2000 into the genus Rhynchotalona Norman, 1903 (Branchiopoda: Cladocera: Chydoridae). Zootaxa, 4613 (3), 463 - 476. https: // doi. org / 10.11646 / zootaxa. 4613.3.3","Korovchinsky, N. M., Kotov, A. A., Sinev, A. Y., Neretina, A. N. & Garibian, P. G. (2021) Water fleas (Crustacea: Cladocera) of North Eurasia. Vol. 2. KMK Press, Moscow, 544 pp.","Roen, U. (1973) Rhynchotalona kistarae sp. n. from South Greenland (Crustacea, Cladocera, Chydoridae, Aloninae). Steenstrupia, 3, 89 - 92.","Sinev, A. Y. & Kotov, A. A. (2014) Revision of the Holarctic genus Rhynchotalona Norman, 1903 (Anomopoda: Chydoridae). Zootaxa, 3841 (2), 188 - 210. https: // doi. org / 10.11646 / zootaxa. 3841.2.2"]}