Ovalona glabra Sars 1901, comb. nov.
Creators: name: Sinev, Artem Y.
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Branchiopoda
Diplostraca
Ovalona
Ovalona glabra

description: XIV. Ovalona glabra (Sars, 1901) comb. nov.
(Figs. 8 I–M)
Richard, 1897: 289–290, Fig. 35–36 (Alona cambouei); Sars, 1901: 49–51, PL. IX, Figs. 6, 6a (Alona); Daday, 1905: 173–174, Taf. XI, Fig. 3–4 (Alona); Delachaux 1919: 28, Pl. 2, Fig. 10 (Alona cambouei); Harding 1955:. 343–344, Figs. 61–64 (Alona cambouei); Ueno, 1967: 559, Fig. 35–36 (Alona cambouei); Megard, 1967: Fig. 29–32 (Alona pulchella); Infante, 1980: 598–599, Fig. 5,a–c (Alona pulchella); Albertina Kameya 1986:135–136, Fig. 6–7 (Alona); Sinev 2001a: 203–280, Figs 1 –40 (Alona); Elmoor-Loureiro et al. 2004: 417, Figs 12–13.(Alona); Kotov, Sinev & Berrios, 2010: 33 (Alona); Sinev & Silva-Brian, 2012: 13–14, Fig.7A –G (Alona).
Type locality. Argentina, Sars (1901) did not give more detailed data on location
Type material. Lectotype (established by Sinev, 2001a): adult female from Argentina, precise location unknown, from G. 0. Sars collection, ZMOU, F12326a. Paralectotypes: 40 females from the same location, together with numerous deformed specimens and exuviae, ZMOU, F12326b.
Material studied earlier. See Sinev (2001a) for the list of material from Argentina and Brazil, Kotov et al. (2010) for material from Chilean Andes; Sinev & Silva-Briano (2012) for material from Mexico.
Diagnosis. Parthenogenetic female. General. Length of adult 0.35–0.46 mm. Body regular oval, height/ length ratio about 0.58–0.62, maximum height at the middle. Ventral margin with about 40–50 setae. Posterodorsal angle with about 60 setulae not organized into groups.
Head. Posterior part of headshield broadly rounded, sometimes with notch at the middle. Three major head pores with connection between them, PP = 0.3–0.5 IP. Lateral head pores minute.
Labrum of moderate size, labral keel broad, with convex anterior margin and a rounded apex; posterior margin of keel without clusters of setulae.
Second abdominal segment without dense setulae. Postabdomen narrow, with parallel margins in postanal portion, length about 2.8–3 height. Distal margin straight; dorso-distal angle prominent, acute with rounded tip. Dorsal margin with distal part about 2 times longer than preanal one; postanal part 1.5 longer than anal one. Postanal portion of distal margin almost straight, anal portion weakly concave. Preanal angle well-defined, postanal angle weakly defined. 7–8 marginal denticles, evenly decreasing in size basally and with 3–5 groups of marginal setulae on anal margin. Eight-nine wide, closely spaced lateral fascicles of setulae, in postanal portion; longest setule in each fascicle as long as longest marginal denticles. Postabdominal claw slightly longer than preanal portion of postabdomen. Basal spine about 0.2 length of claw.
Antennule with antennular seta of half length of antennule, arising at 2/3 distance from the base. Aesthetascs of different length, two longest of them of about half length of antennule.
Antenna with seta arising from basal segment of endopodite reaching the end of endopodite. Spine on basal segment of exopodite slightly shorter than middle segment. Spines on apical segments slightly longer than apical segments.
Limb I with accessory seta about 1/4 length of ODL seta. Limb III with exopodite seta 3 being longest; setae 4 and 6 about 1/3 and 2/5 length of seta 3, respectively; other setae shorter. Limb IV with epipodite with very short projection. Exopodite seta 3 longest; setae 1 slightly shorter than seta 3; seta 2 about 2/3 length of seta 3; seta 5 about 1/2 length of seta 3; setae 4 and 6 shorter than seta 5. Flaming-torch setae with reduced distal portion. Limb V with epipodite with short projection. Exopodite seta 4 four times shorter than seta 1.
Ephippial female with body higher than in parthenogenetic female, ephippium yellow-brown.
Male. General. Length 0.32–0.34 mm. Body low oval, maximum height in the middle of the body, height/ length ratio about 0.58–0.6.
Postabdomen short, narrowing distally; dorso-distal angle rounded, weakly protruding. Length about 2.6 maximum widths. Postanal angle not defined, preanal angle weakly-defined. Distal part of postabdomen 1.5 times longer than preanal one. Gonopores located almost at the end of postabdomen. Unlike in other species of the genus, marginal setulae of postabdomen quite long. Postabdominal claw very short, 2 times shorter than preanal portion of postabdomen; basal spine long, about 0.4 of claw length.
Antennule with male seta arising at 1/4 length from tip, about 1/5 of antennule length.
Limb I with IDL seta 1 absent; setae 2 and 3 subequal in length, two times shorter and thinner than in female; male seta large, hook-like, 1.5 times longer than seta 3. A row of about 11–12 short, robust setulae on ventral face of limb below copulatory brush.
Full description. See Sinev (2001a).
Differential diagnosis. O. glabra is a sibling-species to O. cambouei and O. pulchella. It differs from O. cambouei by connected head pores, and from O. pulchella by the posterior margin of headshield without notches (or, rarely, with single notch at the middle), and by male postabdomen with rectangular distal portion and long marginal setulae. O. glabra differs from O. bromelicola and O. karelica by long basal spine of postabdominal claw; from O. aguascalientensis and O. capensis by fully connected head pores; and from O. archeri by postanal marginal denticles of postabdomen evenly decreasing in size basally.
Distribution. Common in Neotropics (Sinev 2001a; Elías-Gutiérrez et al. 2006), distributed from Argentina to Mexico and South-East USA, present in Andes (Kotov et al., 2010).
description: Published as part of Sinev, Artem Y., 2015, Revision of the pulchella - group of Alona s. lato leads to its translocation to Ovalona Van Damme et Dumont, 2008 (Branchiopoda: Anomopoda: Chydoridae), pp. 451-492 in Zootaxa 4044 (4) on pages 477-478, DOI: 10.11646/zootaxa.4044.4.1, http://zenodo.org/record/235320