Ovalona azorica ( Frenzel & Alonso, 1988 ) Frenzel & Alonso, 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 : 467-468

VI. Ovalona azorica ( Frenzel & Alonso, 1988) comb. nov.

( Figs. 6 F–G)

Frenzel & Alonso, 1988: 449–465, Figs. 1–8 ( Alona ); Alonso, 1996: 331–332, fig. 147 ( Alona ); Sinev, Alonso, Miracle & Sahuquillo, 2012: 60–61, Figs. 8–10 ( Alona ).

Type locality. Lagoa do Canario, Sao Miguel, the Azores.

Type material. Holotype. Parthenogenetic female at the Zoological Museum of Hamburg University, K- 32354; see Frenzel & Alonso (1988) for list of paratypes.

Material studied earlier: see Sinev et al. (2012) for the list of material from Azores and Iberian peninsula.

Diagnosis. Parthenogenetic female. General. Length of adult up to 0.48 mm. Body regular oval, of moderate height, in adults height/length ratio 0.65–0.72, maximum height at the middle. Valves smooth or with small tubercules in dorsal portion. Ventral margin with about 35–45 setae. Postero-dorsal angle with about 100 setulae not organized into groups.

Head. Posterior part of headshield as protruding angle with pointed tip. Three major head pores with a narrow connection between anterior and middle pores, middle and posterior not connected. Posterior pore located very close to head shield margin, distance between medium and posterior pore greatly increases with the size of specimen, varying from 1.5 to 2.5 distances between anterior and middle pore. Lateral head pores minute.

Labrum of moderate size, labral keel narrow, with convex anterior margin and a rounded apex, posterior margin of keel with two clusters of setulae.

Second abdominal segment without dense setulae. Postabdomen of moderate length and width, with parallel margins in postanal portion, length about 2.5 height. Dorsal margin straight in postanal portion, anal margin concave; distal part of postabdomen about 1.5 times longer than preanal one, postanal and anal margins approximately of similar length. Preanal angle well-expressed, prominent, postanal angle weakly defined, distal margin straight, dorso-distal angle rounded. Postanal margin with 5–6 clusters of 2–4 short elementary denticles, only distalmost 1–2 denticles can be composite. About 10 narrow, sparsely spaced lateral fascicles of setulae, in postanal portion distalmost setulae very long and thick, three times longer than marginal denticles. Postabdominal claw slightly shorter than preanal portion of postabdomen. Basal spine weakly curved, about 0.2 of the claw length.

Antennule with antennular seta about 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 thin, as long as endopodite. Seta arising from middle segment of endopodite of same size with apical setae. Apical setae of both branches not differentiated. Spine on basal segment of exopodite slightly shorter than middle segment. Spines on apical segments longer than apical segments.

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

Ephippial female. Body of same height as in parthenogenetic female, maximum height before the middle of the body, ephippium dark yellow-brown.

Male. General. Length 0.28–0.34 mm. Body low oval, maximum height in the middle of the body. Ocellus and eye of same size as in female.

Postabdomen strongly narrowing in anal part, with rectangular postanal part and defined posteroventral angle.

Postanal angle not defined, preanal angle well-defined. Distal part of postabdomen 1.5 times longer than preanal. Sperm duct openings at the end of postabdomen. Clusters of short setulae in place of marginal denticles, lateral fascicles of setulae same as in female. Postabdominal claw two times shorter than that of female, with short basal spine about 0.2 length of claw.

Antennule with male seta arising at 1/4 length from tip, reaching to the end of antennule.

Thoracic limb I with IDL seta 1 absent, setae 2 and 3 short and thin, subequal in length, male seta curved, almost as long as seta 2. On ventral face of limb below copulatory brush a row of 20–25 short thick setulae.

Full description. see Frenzel & Alonso (1988), Alonso (1996) and Sinev et al. (2012).

Differential diagnosis. Ovalona azorica is a sibling-species to O. anastasia , these two species have same morphology of postabdomen and appendages. O. anastasia differs from O. azorica by morphology of main head pores, in O. anastasia distance between middle and posterior pore equal to 1–1.5 distances between anterior and middle pore, remaining more or less the same in specimens of any size, while in O. azorica distance between middle and posterior pore increases with the size of specimen, varying from 1.5 to 2.5 distances between anterior and middle pore. O. azorica and O. anastasia clearly differs from other species of setulosa -clade by morphology of head pores, with connection present only between anterior and middle pore, and by posterior margin of head shield forming an angle.

Distribution. Azores Islands and West Iberia.

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 2. Ovalona nuragica from small temporary pond near Laguna de Bonache, near Siles town, Jaén, Spain. A – E, parthenogenetic female; A – B, same specimen in lateral and latero-frontal view; C, head pores; D, main head pores; E, lateral head pore; F, ephippial female.

FIGURE 3. Ovalona nuragica from small temporary pond near Laguna de Bonache, near Siles town, Jaén, Spain. A – J, parthenogenetic female. A, variability of labral keels; B, postabdomen; C, postanal margin of postabdomen; D, postabdominal claw; E, antennule; F – G, antenna; H – I, thoracic limb II; J, thoracic limb V; K – M, adult male. K, postabdomen; L, distal part of postabdomen; M, antennule.

FIGURE 4. Ovalona nuragica from small temporary pond near Laguna de Bonache, near Siles town, Jaén, Spain. A – E, thoracic limbs parthenogenetic female. A, limb I; B, exopodite of limb III; C, inner portion of limb III; D, exopodite of limb IV; E, inner portion of limb IV; F, adult male, limb I; G – K, parthenogenetic female with abnormal morphology of limbs; G, ejector hooks of limb I; H, endite 1 of limb I; I – J, inner portions of limbs III; K, inner portion of limb IV.

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.

FIGURE 6. A – E, Ovalona anastasia (Sinev, Alonso, Miracle & Sahuqillo, 2012), from Sinev et al., (2012). A – C, parthenogenetic female. A, lateral view; B, head pores; C, postabdomen; D – E, adult male. D, lateral view; E, postabdomen; F – G, Ovalona azorica (Frenzel & Alonso, 1988), from Sinev et al. (2012), parthenoghenetic female. F, head pores; G, postabdomen; H – L, Ovalona setulosa (Megard, 1967), from Sinev (2009). H – J, parthenogenetic female. A, lateral view; J, head pores; I, postabdomen; K – L, adult male. K, lateral view; L, postabdomen.

FIGURE 7. A – B, Ovalona weinecki (Studer, 1878), parthenogenetic female. A, lateral view, redrawn from Frey, 1988; B, postabdomen, redrawn from Van Damme & Dumont, 2008; C – G, Ovalona archeri (Sars, 1988), from Sinev (2002 c). C – E, parthenogenetic female. C, lateral view; D, head pores; E, postabdomen; F – G, adult male. F, lateral view; G, postabdomen; H – N, Ovalona aguascalientensis (Sinev & Silva-Briano, 2012), from Sinev & Silva-Briano (2012). H – L, parthenogenetic female. H, lateral view; I, posteroventral margin of valves; J – K, head pores; L, postabdomen; M – N, adult male. M, lateral view; N, postabdomen.

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.

FIGURE 9. Ovalona cambouei (Guerne & Richard, 1983) from paddy field near Shorkul' lake, Khoresm Area, Uzbekistan. A – H, parthenogenetic female. A, lateral view; B, ventral margin of valves; C, posteroventral margin of valves; D – E, headshield; F – G, head pores; H, postabdomen; I, ephippial female; J – K, adult male. J, lateral view; K, postabdomen.

FIGURE 10. Ovalona cambouei (Guerne & Richard, 1983) from paddy field near Shorkul' lake, Khoresm Area, Uzbekistan. A – N, parthenogenetic female. A – B, labrum; C, antennule; D, antenna; E, limb I; F, IDL and ODL of limb I; G, limb II; H, exopodite of limb III; I – J, inner portion of limb III; K, exopodite of limb IV; L – M, inner portion of limb IV. N, limb V. O – Q, adult male. O, limb I; P. copulatory hook and IDL of limb I; Q, antennule.