Flavalona margipluma Sinev & Dumont 2016

Flavalona margipluma

(Sousa, Santos, Güntzel, Diniz, de Melo Junior & Elmoor-Loureiro, 2015) comb. nov.

Alona margipluma Sousa, Santos, Güntzel, Diniz, de Melo Junior & Elmoor-Loureiro, 2015: 445–455, figs 1–4.

Alona iheringula – Silva, Abreu, Orlando, Wisniewski & Santos-Wisniewski 2014: 2–5, fig. 1.

Diagnosis (according to Sousa et al. 2015)

Female

Length of adult 0.32–0.43 mm. Body regular oval, maximum height at mid-body, height/length ratio about 0.65. Valves from previous molts not retained. Posteroventral angle without setules protruding beyond valve margins. Ventral margin with 45–50 setae. Valves covered by thin, sparsely spaced longitudinal lines.

Eye larger than ocellus. Rostrum short, broadly rounded. Posterior margin of head shield broadly rounded. Three major head pores, middle pore slightly smaller than others, located near posterior pore. Connection between middle and posterior pore wide, connection between middle and anterior pore narrow. PP ca 0.7–0.95 IP. Lateral head pores of ca 0.7–0.85 IP length, lateral pore pockets rounded, with depth about 1.5 of pore length. Labral keel without denticles.

Postabdomen truncated, length 2.4–2.6 heights. Distal margin straight, distal angle prominent, acute with rounded tip. Dorsal margin weakly convex in preanal part, concave in anal part, straight in postanal part. Distal part of dorsal margin 3 times longer than preanal one, with preanal portion 1.3–1.5 times longer than anal one. Preanal and postanal angles weakly defined. Postanal margin of postabdomen provided with 11–13 marginal denticles. Anal margin with 4–5 clusters of marginal setules. About 10 lateral fascicles of setules, distal setules in fascicle being longest. Postabdominal claw of moderate length, longer than preanal portion of postabdomen. Basal spine small, its length less than width of postabdominal claw base.

Antennule with longest aesthetasc of about 2/3 length of antennule. Scrapers of limb II of similar morphology. Exopodite III with seta 6 of ca 2/3 length of seta 3. Exopodite IV with seta 3 being longest, setae 1–2 slightly shorter, setae 4–6 ca 0.5 length of seta 3. Epipodite IV and V with processes as long as the epipodite itself. Exopodite V not bilobed.

Male

Unknown.

Differential diagnosis

Flavalona margipluma comb. nov. differs from F. setigera comb. nov. by three main head pores, from F. natalensis comb. nov. and F. cheni comb. nov. by deep pockets of lateral head pores (in these species the depth of the pockets is less than half the depth of the pore). It also differs from F. natalensis comb. nov. by its costata -like valve sculpture. Flavalona margipluma comb. nov. is similar in morphology to F. costata comb. nov., but differs in exopodite V not separated into two lobes and in basal spine of postabdomen shorter than the width of claw base. Unique to the species is the bottle-shaped main sensillum of limb IV. Sousa et al. (2015) suggested that the presence of thin setules between the bases of setae on the ventral valve margin is unique to F. margipluma comb. nov., but such setules are present in all Flavalona gen. nov., yet were overlooked in previous studies.

Type material

Holotype

Adult parthenogenetic ♀, the Museum of Zoology of the University of São Paulo, MZUSP 33196.

Paratypes

See Sousa et al. (2015) for the list of paratypes.

Type locality

BRAZIL: Criminosa Lake, Porto Murtinho, Pantanal, Mato Grosso do Sul, 21º40ʹ28.8″ S, 57º53ʹ28.5″ W.

Distribution

So far known from Mato Grosso do Sul state, Pernambuco state and Distrito Federal of Brazil (Sousa et al. 2015). In littoral zone of lakes among macrophytes.