Alona affinis

Alona affinis (Leydig, 1860)

(Fig. 6 G–L, 7)

Baird, 1843: 92–93, Pl. 3: Figs. 9–11 (quadrangularis); Liévin, 1848: 40, Pl. 10: Figs. 6–7 (quadrangularis); Leydig, 1860: 233, Pl. 9: Figs. 68–69 (Lynceus); Sсhödler, 1863: 18–19, Pl. 1: Figs. 17–22 (spinifera); P. E. Müller, 1867: 175–176, Pl. 3: Figs. 22–23, Pl. 4: Figs. 1–2 (oblonga); Stingelin, 1895: 244–246, Pl. 7: Figs. 32–33; Lilljeborg, 1901: 454–461, Pl. 66: Figs. 18–21, Pl. 67, Figs. 1 –17 (Lynceus); Stingelin, 1906: 324–325, Pl. 13: Fig. 18; Behning, 1941: 312–315, Fig. 129; Herbst, 1962: 89, Fig. 69; Smirnov, 1971: 467–474, Figs. 582–588, 590 (Biapertura); Flössner, 1972: 318–321, Pl. 151; Negrea, 1983: 325–329, Fig. 133A–P (Biapertura); Alonso, 1996: 345–346, Fig. 154A–S; Sinev, 1997: 47–55, Figs. 1–3; Sinev, 1998: 58, Flössner, 2000: 297–300, Pl. 110; Fig. 5; Sinev, 2000: 197–202, Figs. 1 –22; Sinev, 2009: 49–51, Figs. 5–6; Hudec, 2010: 306–309, Pl. 73.

Material studied here. Samples, where Alona affinis coexists with A. sibirica sp. nov. are marked by asterisk. Russia: Moscow Area: over 40 parthenogenetic female, 7 ephippial females, 4 adult males from Glubokoe Lake, Ruza district, N 55.75361°, E 36.50417°, 26.09.2019 and 06.10.2019, coll. A.Y. Sinev, N.M. Korovchinsky; over 20 parthenogenetic females from a pond in Tugoles’e-Vozmezhnyi, Shatura district, 55.56242°, E 39.82352°, 4.08.2014, coll. A.A. Zharov, AAK M-2730. Khanty -Mansi Autonomous Area: 1 parthenogenetic female from Lake Pionerskoe, near town of Nizhnevartovsk, N 60.92624°, E 76.47915°, 23.07.2005, coll. A. A. Kotov, AAK 2005-324. Tomsk Area: 5 parthenogenetic females from an affluent on Island Gusiniy, Rivet Ob’, N 56.40743°, E 84.04662°, 18.07.2005, coll. A. A. Kotov, AAK-2005-293; *1 parthenogenetic female from a mine-lake near road Tomsk-Mel’nikovo, N 56.53575°, E 84.13392°, 20.07.2005, coll. A. A. Kotov, AAK 2005-298. Sakha (Yakutia) Republic: 2 parthenogenetic females from an affluent on Melnikova island, River Lena, N 63.86428°, E 127.4509°, 21.08.2010, coll. A. A. Kotov, AAK 2011-019. Kamchatka Area: 1 parthenogenetic females from River Bystraya, N 52.93035°, E 156.6031°, 14.09.2006, coll. T. N. Travina, AAK 2009-078; 2 parthenogenetic females from River Bolshaya near the KamchatNIRO Field station, N 52.76123°, E 156.2647°, 13.08.2009, coll. T. N. Travina, AAK 2009-079; 1 parthenogenetic female from an affluent of River Bystraya, N 52.93035°, E 156.6031°, 17.08.2009, coll. A. A. Kotov, AAK 2009-094; *1 parthenogenetic female, 1 juvenile male of instar II from small pool in sphagnum bog near Bolshaya River, N 52.76419°, E 156.2536°, 24.08.2009 coll. A. A. Kotov, AAK 2009-098; 3 parthenogenetic females from a swampy area near Travianoy Cape on Kurilskoe Lake, N 51.41718°, E157.0454°, 08.2009, coll. A. A. Kotov, AAK 2009-103; 3 parthenogenetic females from Kurilskoe Lake, N 51.41754°, E 157.0459°, 08.2009, coll. A. A. Kotov, AAK 2009-104; 12 parthenogenetic females, 1 ephippial female, 2 males from overgrown pool at Kronotsky Nature Reserve, N 54.23201°, E 160.1616°, 21.08.2014, coll. E.I.Bekker, F. V.Kazansky, AAK M-3027. Mongolia: 3 parthenogenetic females from Tolbo Nuur lake near Tolbo town, Bayan-Ulgii Aimag, N 48.52647°, E 90.14866°, 24.08.2006, coll. C. Jersabek, AAK 2008-078; 1 parthenogenetic female from Buyant Gol (river) near Khovd town, Khovd Aimag, N 47.99126°, E 91.61514°, 14.08.2006, coll. C. Jersabek, AAK 2008-075; *5 parthenogenetic females Uhegiin Gol (river) near Tes town, Uvs Aimag, N 50.49443°, E 93.60029°, 30.08.2006, coll. C. Jersabek, AAK 2008-082; 5 parthenogenetic females from Hoid Gol (river) near Zuungovi town, Uvs Aimag, N 50.03106°, E 94.02315°, 11.09.2006, coll. C. Jersabek, AAK 2008-088; 2 parthenogenetic females from Shar Nuur lake near Hanh (town), Huvsgul Aimag, N 51.08128°, E 99.70592°, 28.07.2005, coll. C. Jersabek, AAK 2008-012; 2 parthenogenetic females from Dalbain Gol (river) near Hanh (town), Huvsgul Aimag, N 47.96486°, E 107.5964°, 01.08.2005, coll. C. Jersabek, AAK 2008-016; 3 parthenogenetic females from Urt Tsaramiin Nuur (lake) near Hatgal town, Huvsgul Aimag, N 47.68809°, E 102.691°, 02.08.2005, coll. C. Jersabek, AAK 2008-018;1 parthenogenetic female from Ugii Nuur (lake), Arkhangai Aimag, N 47.63°, E 102.51°, 18.08.2005, coll. C. Jersabek, AAK 2008-030; 2 parthenogenetic females from Shireetiin Nuur (lake) near Uyanga town, Arkhangai Aimag, N 46.52211°, E 101.831°, 29.07.2006, coll. C. Jersabek, AAK 2008-062; 3 parthenogenetic females from Tuul Gol (river) near Terelj town, Tuv Aimag, N 47.75037°, E 102.7697°, 09.07.2005, coll. C. Jersabek, AAK 2008-005.

Material studied earlier. See Sinev (1997, 2000) for the list of material from Eurasia (A. affinis var. affinis and A. affinis var. ornata) and Sinev (2009) for the list of material from South Africa.

Comments. All studied material, including that from populations coexisting with A. sibirica sp. nov., fully agree with the early detailed redescriptions of the species (Alonso, 1996; Sinev, 1997, 2000, 2009; Hudec, 2010). In Lake Glubokoe (Moscow Area), both females and males of Alona affinis (Fig. 6 G–L) were found together with these of A. sibirica sp. nov. in the same sample. Importantly, morphology of males from Kamchatka populations of A. affinis (Fig. 7) did not differ in any details from that of European populations.

1 Trunk limb I with IDL seta 1 thin, straight, not claw–like, about half length of seta 2....... Alona lepida Birge, 1892 (USA)

- Trunk limb I with IDL seta 1 thick, strongly curved, claw–like, of similar length with seta 2.......................... 2

2 Posteroventral angle of valves with denticles............. Alona sibirica sp. nov. (North Europe, North and Central Asia).

- Posteroventral angle of valves without denticles............................................................. 3

3 Postabdomen of female evenly narrowing distally in postanal portion............................................ 4

- Postabdomen of female with parallel margins in basal half of postanal portion..................................... 5

4 Spine on basal segment of antenna exopodite as long or longer than middle segment.................................................................................................. Alona elliptica Sinev, 1997 (East Australia)

- Spine on basal segment of exopodite much shorter than middle segment......... Alona martensi Sinev, 2009 (South Africa)

5 PP in adult females about 2.5-3 IP...................................... Alona kendallensis Henry, 1919 (Australia)

- PP in adult females about not exceeding 2 IP................................................................ 6

6 Postabdomen of adult male with right, clearly defined distoventral angle...... Alona affinis (Leydig, 1860) (Eurasia, Africa)

- Postabdomen of adult male with rounded distoventral angle..... Alona ossiani Sinev, 1998 (North and South America, South Korea), two subspecies.................................................................................7.

7 Postabdomen of adult male without any marginal denticles................... Alona ossiani ossiani Sinev, 1998 (Brazil)

- Postabdomen of adult male with 1–3 marginal denticles at postanal angle........................................................................................... Alona ossiani herricki Sinev, 2013 (USA, Canada, South Korea)

Molecular analysis. For a preliminary evaluation of the genetic diversity within Alona, we provisionally subdivided all studied alonines into two large groups based on their morphological characters: (1) “true” Alona and (2) artificial group named “others” which could be paraphyletic. Our analysis confirmed that such subdivision is adequate (Table 2), although information on some loci was not complete. The Alona have a high haplotypic and nucleotide diversity and relatively low G+C rate in the protein-coding gene COI what is probably characteristic of all chydorids (Kotov et al. 2016). In contrast, nuclear 18S rDNA has a higher G+C rate and a lower nucleotide diversity, as it is known in some other arthropods (Reumont et al. 2009). Results of the neutrality tests for different populations could suggest similar demographic processes in different lineages and different loci. Both for the Alona ’s and “others”, the results of neutrality tests (Fs>>0; R2>0) confirm a high genetic differentiation and chance of population divergence/mixing. Such results pushed us to study in detail the genetic diversity within each group and resolving of taxonomic uncertainty within these lineages.