Ovalona bromelicola (Smirnov, 1988) Smirnov, 1988

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 : 476-477

XIII. Ovalona bromelicola (Smirnov, 1988) comb. nov.

( Figs. 8 E–H).

Smirnov. 1988: 65–72. Fig. 1 –15 (Alona). Sinev 2002 b: 109–116, Fig. 1 –36 (Alona).

Type locality. Nicaragua, neighborhood of Managua, Mt. Mombacho, water accumulated in epiphytic bromeliads.

Type material. Holotype. Parthenogenetic female, MGU NNS slide 3448. Allotype. Adult male MGU NNS slide 3374. Paratypes. 6 parthenogenetic females, MGU NNS slides 3495, 3496, 3497, 3500, 3501, 3504; 3 adult males, MGU NNS slides 3356, 3446, 3447.

Material studied earlier. See Sinev (2002b) for the list of material from Nicaragua.

Diagnosis. Parthenogenetic female. General. Length of adult female 0.40–0.51 mm. Body regular oval, rather high; in adults height/length ratio about 0.6–0.7, maximum height before the middle of the body. Ventral margin with 45–60 setae. Postero-dorsal angle with about 100 setulae not organized into groups. Eye and ocellus very small, much smaller than in all other species of the genus.

Head. Posterior part of head shield broadly rounded. Three connected major head pores, PP = 0.8–1.0 IP. Lateral head pores minute. 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, curved, with convex ventral and concave dorsal margins and prominent dorso-distal angle; length about 2.9–3.1 height. Ventral margin strongly convex. Dorsal margin with distal part 1.5 times longer than preanal one; postanal and anal portions of similar length. Postanal and anal portion of distal margin evenly concave. Preanal angle well-defined, postanal angle not defined. Distal margin straight, dorso-distal angle protruding, with rounded tip. 5–7 large marginal denticles in distal part, followed by seven-eight groups of marginal spinules and setulae, decreasing in size basally. Nine-ten wide lateral fascicles of setulae; distalmost seta of each fascicle slightly longer and thicker than others; in postanal portion, longest setule in each fascicle of similar length with distal marginal denticles. Distance between fascicles in postanal portion about half width of fascicles. Postabdominal claw 1.2 times longer than preanal portion of postabdomen. Basal spine very small, straight, thin, less than 0.1 length of claw.

Antennule with antennular seta about 2/3 length of antennule, arising almost at the middle of antennule. Aesthetascs very short, two longest of them of about 0.3 length of antennule.

Antenna with seta arising from basal segment of endopodite longer than endopodite. Spine on basal segment of exopodite about 2/3 length of middle segment. Spines on apical segments shorter than apical segments.

Limb I with accessory seta about 1/3 length of ODL seta. Limb III with exopodite seta 3 being longest; setae 4 and 6 about 1/3 length of seta 3; seta 1 about 1/4 length of seta 3; other setae short. Limb IV with epipodite with long projection. Exopodite setae 1–3 and 4 of similar length; setae 5 and 6 about 1/2 length of seta 4. Flaming-torch setae with well-developed distal portion. Limb V with epipodite with very long projection. Exopodite seta 4 three times shorter than seta 1.

Ephippial female unknown.

Male. General. Length 0.33–0.36 mm. Body low oval, maximum height in the middle of the body, body height/body length about 0.6. Ocellus as large or larger than eye.

Postabdomen narrow, moderately long, with parallel margins in postanal part; dorso-distal angle weakly protruding, rounded. Preanal angle well-defined, postanal angle not defined. Distal part of postabdomen 1.7 times longer than preanal one. Clusters of short setulae in place of marginal denticles, lateral fascicles of setulae same as in female. Postabdominal claw long, as long as preanal portion of postabdomen, without basal spine.

Full description. See Sinev (2002a).

Differential diagnosis. O. bromelicola differs from most Ovalona by the short basal spine of the postabdominal claw, a character shared only by O. karelica . Unique characters of the species are antennule with short aesthetascs, curved postabdomen, and small eye and ocellus.

Distribution. Inhabits water-filled epiphyte bromeliads of rain forests, so far known from Nicaragua only.

Figures

FIGURE 1. Ovalona nuragica from small temporary pond near Laguna de Bonache, near Siles town, Jaén, Spain. A, juvenile female of instar I; B, juvenile female of instar II; C – I, adult parthenogenetic female; C – D, lateral view; E, ventral margin of valves; F, setae from posterior part of ventral margin of valves; G, posteroventral angle of valves; H, head shield; I, head pores; J, ephippial female; K, adult male.

FIGURE 8. A – D, Ovalona capensis (Rühe, 1921), parthenogenetic female, redrawn from Van Damme et al., 2013. A, lateral view; B, rostrum; C, head pores; D, postabdomen; E – H, Ovalona bromelicola (Smirnov, 1988) parthenogenetic female, from Sinev (2002 b). E, lateral view; F, head pores; G, postabdomen; H, antennule; I – M, Ovalona glabra (Sars, 1901), I and K – M from Sinev & Silva-Briano (2012), J from Sinev (2001 a). I – K, parthenogenetic female. I, lateral view; J, head pores; K, postabdomen; L – M, adult male. L, lateral view; M, postabdomen.