Ovalona altiplana ( Kotov, Sinev & Berrios, 2010 ) Kotov, Sinev & Berrios, 2010

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), Zootaxa 4044 (4), pp. 451-492 : 462-463

III. Ovalona altiplana ( Kotov, Sinev & Berrios, 2010) comb. nov.

( Figs. 5 I–K)

Megard 1967: p. 46, figs 29–32 ( Alona pulchella ); Dominguez 1973, p. 3–7, figs 13–14 ( Alona pulchella var. cambouei ); Kotov, Sinev & Berrios 2010: 40–47, Fig. 19–22 ( Alona )

Type locality. Crater Lake, Licancabur Volcano, Chile-Bolivia border.

Type material. Holotype: adult parthenogenetic female, MGU Ml 95.

Paratypes: 20 parthenogenetic females, MGU Ml 96; 40 parthenogenetic females, AAK M-0410.

Material examined earlier. See Kotov et al. (2011) for the list of material from Chile.

Diagnosis. Parthenogenetic female. General. Length of adult 0.42–0.50 mm. Body regular oval, maximum height at the middle, height/length ratio about 0.64–0.68. Ventral margin with 35–45 setae. Postero-dorsal angle with 35–50 setulae not organized into groups.

Head. Posterior part of head shield broadly rounded. Three connected major head pores, PP about 0.3 IP. Lateral head pores minute.

Labrum. Labral keel moderately wide, with convex anterior margin, rounded apex, and posterior margin without clusters of short setulae.

Second abdominal segment without dense setulae. Postabdomen of moderate width, with almost parallel margins in postanal portion, length about 2.5 heights. Distal margin straight, distal angle almost right, with rounded tip. Postanal portion of distal margin straight, anal portion weakly concave. Dorsal margin with distal part 1.3–1.5 times longer than preanal one, anal and postanal portions of similar length. Preanal angle well-defined, postanal angle not defined. 5–6 rather long marginal denticles of similar size, their length exceeding width of postabdominal claw base, and with 4–5 groups of marginal setulae on anal margin. Eight-eleven closely spaced lateral fascicles of setulae, six-seven distalmost fascicles broad, densely spaced, with distalmost seta of each fascicle as long as marginal denticles. Postabdominal claw of moderate length, slightly longer than preanal portion of postabdomen. Basal spine about 0.25 of length of claw.

Antennule with antennular seta thin, about 1/3 length of antennule, arising at 2/3 distance from the base. Aesthetascs of different length, longest of them of about half length of antennule. Antenna with seta arising from basal segment of endopodite as long as endopodite. Spine on basal segment of exopodite shorter than middle segment. Spines on apical segments longer than apical segments.

Limb I with accessory seta about 1/4 length of ODL seta. Limb III with exopodite seta 3 being longest, seta 6 about 1/2 length of seta 3, other setae less than 1/4 length of seta 3. Limb IV with epipodite without projection. Exopodite seta 3 longest, setae 1 and 2 slightly shorter than seta 3, seta 4 about 2/3 length of seta 3, setae 5 shorter than seta 4, setae 6 shorter than seta 5. Flaming-torch setae with well-developed distal portion. Limb V with epipodite without projection. Exopodite seta 4 three times shorter than seta 1.

Ephippial female. Unknown.

Male. Unknown.

Full description. See Kotov et al. (2010).

Differential diagnosis. O. altiplana is similar in shape and morphology of postabdomen to O. setulosa , but differs from it, and from O. azorica and O. anastasia , by uninterrupted connection between head pores. It differs from other species of setulosa -group: O. anamariae , O. kaingang and O. weinecki , by distinctive postanal marginal denticles of postabdomen, which are long, slender, of similar length; length of all denticles exceed width of postabdominal claw base.

Distribution. Known from freshwater lakes at Andes of North Chile and Bolivia.

Figures

FIGURE 5. A – H, Ovalona nigra (Smirnov, 1996), from Kotov et al. (2010). A – E, parthenogenetic female. A, lateral view; B, head pores; C, middle segment of abdomen; D, postabdomen; E, postanal margin of postabdomen; F – H, adult male. F, lateral view; G, postabdomen; H, distal portion of postabdomen; I – K, Ovalona altiplana (Kotov, Sinev & Berrios, 2010), from Kotov et al. (2010), parthenogenetic female. I, lateral view; J, head pores; K, postabdomen; L – O, Ovalona anamariae (Sinev & Silvabriano, 2012), from Sinev & Silva-Briano (2012), parthenogenetic female. L, lateral view; M, ventral margin of valves; N, head pores; O, postabdomen.