Alona glabra Sars, 1901

Sinev, Artem Y. & Silva-Briano, Marcelo, 2012, Cladocerans of genus Alona Baird, 1843 (Cladocera: Anomopoda: Chydoridae) and related genera from Aguascalientes State, Mexico, Zootaxa 3569, pp. 1-24 : 13-15

Alona glabra Sars, 1901

( Fig 7 )

Sars, 1901, p. 49–51, Pl. 9: figs. 6, 6a; Richard 1897, p. 289–290, figs 35–36 ( cambouei ); Daday 1905, p. 173–174, Pl. 11, figs 3–4; Delachaux 1919, p. 28, Pl. 2, fig. 10 ( cambouei ); Harding 1955, p. 343–344, figs. 61–64 ( cambouei ); Uéno 1967, p. 559, figs 35–36 ( cambouei ); Infante 1980, p. 598–599, figs 5a–c ( pulchella ); Albertina Kameya 1986, p. 135–136, fig. 6–7; Sinev 2001a, p. 203–280, figs 1–40; Elmoor-Loureiro et al. 2004, p. 417, figs 12–13; Kotov, Sinev & Berrios, 2010: 33.

Type locality of A. glabra is " Argentina ", no further information was given by Sars (1901).

Lectotype. Female, GOS F12326a.

Studied material: 12 parthenogenetic females, 2 males from pond between El Picacho and Loma La Plata mountains. Aguascalientes. 23.10.1988 AYS; 20 parthenogenetic females from pond beside highway Aguascalientes city – Calvillo city. Calvillo, Aguascalientes, 0 3.09.1991, AYS.

Comments. Both females ( Figs. 7A–B ) and males ( Fig. 7C–E ) were found. Morphology of the studied specimens completely agrees with the recent redescription of the species ( Sinev 2001a). In our material there were no specimens with tuberculated valves, reported by Kotov et al. (2010) for Andean populations.

In course of the redescription of the species, Sinev (2001a) did not provide a description of male antennule. In studied male specimens, antennule ( Fig. 7E ) moderately thick, length about 2 widths, provided with two lateral and ten terminal aesthetascs of similar length, about 2/3 length of antennule. Male seta short and thick, arising at 3/4 distance from the base, not reaching to the end of antennule. Such morphology of antennule is typical for the group, recorded for all species with known males.

In Aguascalientes, Alona glabra can be at first glance confused with A. aguascalientensis sp. nov. specimens without denticles on posteroventral corner of valves. But A. glabra clearly differs by connected major head pores, protruding distal angle of postabdomen and by the morphology of postanal marginal denticles of postabdomen. In A. glabra , two-three distalmost denticles are significantly larger than others, while in A. aguascalientensis sp. nov., all denticles are of the same size. Male of A. glabra clearly differs from that of A. aguascalientensis sp. nov. by a shorter basal spine of the postabdominal claw.

Distribution. Common in Neotropics, including Mexico ( Sinev 2001a; Elías-Gutiérrez et al. 2008a), encountered in Chilean and Bolivian Andes as well as in lowland (Kotov et al. 2010; Coronel et al. 2007). In Aguascaliantes, A. glabra is found in the south of the state, close to the subtropical region.

Figures

FIGURE 7. A – E, Alona glabra Sars, 1901 from pond between El Picacho and Loma La Plata mountains. Aguascalientes State, Mexico. A – B, parthenogenetic female. A, lateral view. B, postabdomen. C – E, male. C, lateral view. D, postabdomen. E, antennule. F – J, Alona setulosa Megard, 1967. F – I, from pond near Laguna Seca pond, San Josй de Gracia, Aguascalientes state, Mexico, parthenogenetic female. F, lateral view. G, head pores. H – I, postabdomen. J, ephippial female from pond near road to Los Arquitos town (in El Cariñan farm), Jesús María, Aguascalientes State, Mexico. Scale bars denote 0.1 mm for A, C, F, J, 0.05 mm for B, D – E, G – I.