Ovalona kaingang (Sousa, Elmoor-Loureiro & Santos, 2015) Sousa, Elmoor-Loureiro & Santos, 2015

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 : 468-469

VII. Ovalona kaingang (Sousa, Elmoor-Loureiro & Santos, 2015) comb. nov.

Sousa, Elmoor-Loureiro & Santos, 2015a: 1–12, Fig. 1–4 ( Alona ).

Type locality. Pond in Sao Simao, Mostardas, Rio Grande do Sul state, Brazil (30 57′ 06″ S, 50 42′ 29″ W).

Type material. Holotype - parthenogenetic female at Museum of Zoology of the University of Sao Paulo, access number MZUSP 29593. For the list of paratypes see Sousa et al. (2015a).

Diagnosis. Diagnosis based on published description. Parthenogenetic female. General. Length of adult female 0.33–0.40 mm. Body ovoid, of moderate height, height/length ratio about 0.63, maximum height after midline. Ventral margin with about 40–50 setae. Postero-dorsal angle with about 50 setulae not organized into groups.

Head. Posterior part of head shield broadly rounded. Three connected major head pores, PP less than 0.2 IP. Lateral head pores minute.

Labrum. Labral keel of moderate width, with convex anterior margin and blunt or rounded apex, posterior margin of keel without clusters of setulae.

Second abdominal segment without dense setulae. Postabdomen short and wide, weakly narrowing distally, length about 2–2.4 height. Ventral margin straight. Distal margin straight, distal angle right or obtuse, with rounded tip. Dorsal margin with almost straight postanal portion and concave anal portion. Distal part 1.5 times longer than preanal, anal and postanal portions of similar length. Preanal angle well-defined, postanal angle weakly defined. Postabdomen with 6 short marginal denticles on postanal margin and with 3–4 groups of setulae on anal margin. Eight-nine moderately wide, sparsely spaced lateral fascicles of setulae, with distalmost setulae in postanal fascicle longer than marginal denticles. Postabdominal claw of moderate length, equal in length to preanal portion of postabdomen. Basal spine about 0.3 length of claw.

Antennule with antennular seta about 1/2 length of antennule, arising at 2/3 distance from the base. Aesthetascs of different length, two longest of them of about 2/3 length of antennule. Antenna with seta arising from basal segment of endopodite shorter than endopodite. Spine on basal segment of exopodite slightly shorter than middle segment. Spine on apical segment of exopodite longer than apical segment of exopodite, spine on apical segment of endopodite of same length than apical segment of endopodite.

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

Ephippial female unknown.

Male. General. Length 0.27–0.3 mm. Body low oval, maximum height in the middle of the body, height/length ratio about 0.55. Ocellus smaller than eye.

Postabdomen short, narrowing distally in anal portion and subrectangular in postanal portion, dorso-distal angle broadly rounded. Preanal angle well-defined, postanal angle not defined. Distal part of postabdomen only slightly longer than preanal. Clusters of short setulae in place of marginal denticles, lateral fascicles of setulae same as in female. Postabdominal claw 2 times shorter preanal portion of postabdomen, basal spine of about 0.3 claw length.

Antennule with male seta arising at 1/4 length from tip, not reaching to the end of antennule.

Thoracic limb I with IDL seta 1 absent; setae 2 and 3 short, but robust, subequal in length; male seta curved, almost as long as seta 2. On ventral face of limb below copulatory brush a row of about 15 short thick setulae.

Full description. see Sousa et al. (2015a).

Differential diagnosis. O. kaingang differs from O. anastasia , O. azorica and O. setulosa by uninterrupted connection between head pores. O. kaingang differs from O. anamariae by the absence of long posteriormost seta in the anterior group of ventral setae of valves and by postabdomen with parallel margin in postanal portion. O. kaingang differs from O. altiplana by morphology of postanal marginal denticles of postabdomen (in O. altiplana , all denticles are long and narrow, of similar length, their length exceeding width of postabdominal claw base). O. kaingang differs from O. weinecki b y smaller size (size of adult O. weinecki 0.5–0.65 mm), smaller IP/PP ratio (PP = 0.6–0.7 IP in O. weinecki ) and postabdomen with defined dorsodistal angle and composite marginal denticles of postabdomen.

Distribution. Minas Gerais state and Rio Grande do Sul state, Brazil.

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.