Oocyclus ovalis, Alencar & Short & Hamada, 2022

Alencar, Janderson Batista R., Short, Andrew Edward Z. & Hamada, Neusa, 2022, New species and new distributional records of the hygropetric water scavenger beetle genus Oocyclus Sharp (Coleoptera, Hydrophilidae) from the Brazilian Shield, Zootaxa 5087 (2), pp. 275-305 : 288-290

publication ID

https://doi.org/ 10.11646/zootaxa.5087.2.3

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scientific name

Oocyclus ovalis

sp. nov.

Oocyclus ovalis View in CoL sp. n.

( Figs. 7a–e View FIGURE 7 , 11f View FIGURE 11 , 12c View FIGURE 12 , 13a View FIGURE 13 , 14 View FIGURE 14 )

Type material. Holotype (male): “ BRASIL: MINAS GERAIS, Serro, Waterfall of Malheiros , long -43.4459, lat -18.6541, 738 m a.s.l., rock-face seepages, 31.iii.2020, leg. J.B. R. Alencar” ( INPA, Coleoptera , in alcohol) . Paratypes (14 exs.): BRAZIL: Minas Gerais: Same data as holotype (10 exs. INPA ; 4 exs. SEMC, in alcohol) .

Diagnosis. Medium-sized species. Pronotum with rounded posterolateral margins. Elytra surface even, with rows of fine systematic punctures bearing short setae, interrupted in some regions along their length; lateral rows very indistinct, blending with surrounding ground punctation. Elytral sutural interval not raised ( Fig. 12c View FIGURE 12 ). Prosternum with two or four anteromedial spine-like setae. Abdominal ventrites brown to dark brown, not paler than thoracic ventrites.

Adult. Body length 4.0– 4.4 mm (n= 10, mean= 4.21, SD= ±0.21); TL/GW 1.55 ± 0.08 mm. General body shape broadly oval, strongly convex.

Color. Dorsum black ( Fig. 7a View FIGURE 7 ), covered with dense, irregular green or bronze sheen. Anterolateral margins of pronotum with pale strip, extending to ca. 4/5 of lateral margin length. Elytra with irregular patches of bronze or green iridescence; without row of rounded black [=without sheen] spots along suture. Each elytron with one rounded pale spot on distal quarter. Antennomeres 1–5 yellowish brown, club dark brown. Maxillary and labial palps yellow. Ventral face of head dark brown to black. Lateral margins of prosternum; pseudoepipleura and epipleura yellowish brown. Thorax, ventrally brown to black. Legs brown with bronze or green iridescence, except for light brown tarsi. Abdominal ventrites brown to dark brown.

Head. Ground punctation on clypeus and frons moderately coarse, distance between punctures 2.0–3.0×width of one puncture ( Fig. 7d View FIGURE 7 ). Ground punctation on labrum denser than punctation of clypeus, distance between punctures 0.5–1.5×width of one puncture; with few distinct systematic punctures medially. Labrum sometimes bearing short setae. Clypeus with few distinct systematic punctures along anterolateral margins, larger than surrounding punctation and sometimes bearing short setae. Frons with irregular row of systematic punctures toward the median plane of each eye and few fine setae around ocular suture. Maxillary palps subequal in length to width of labrum; segment 3 shorter than segment 2; apical segment longer than penultimate segment. Labial palps about two-thirds as long as width of mentum. Mentum smooth, with scattered coarse punctures; subquadrate, anterior margin slightly convex and depressed.

Thorax. Ground punctation on pronotum and elytra evenly distributed and moderately coarse ( Figs. 7a, c, d View FIGURE 7 ). Pronotal systematic punctures with short fine setae, at least 2× size of surrounding ground punctures; anterior and posterior series each forming an irregular field. Lateral margins of pronotum with fine setae distributed along of its length, being more densely pubescent on anterior half. Pronotal posterolateral angles broadly rounded. Sutural interval on elytra not raised ( Fig. 12c View FIGURE 12 ). Elytral interval with weak or non-existent pubescence in ground punctation. Five rows of systematic punctures: rows 1 and 2 each bearing one small recumbent setae; punctures not larger than surrounding punctuation and at about the same spacing. Rows 3–5 each represented by punctures not larger than surrounding ground punctuation; bearing short setae and as such hardly distinguishable ( Fig. 12c View FIGURE 12 ). Elytral surface without shallow longitudinal depressions medially on posterior half ( Fig. 13a View FIGURE 13 ). Humeral region (in frontal view) without anteromedial elevation. Elytral margins with short spine-like setae situated along their length. Prosternum with clearly defined median carina, slightly elevated anteromedially ( Fig. 7e View FIGURE 7 ); elevated region with two or four spine-like setae. Elevated process of mesoventrite wide and elongate, about twice as long as wide; slightly raised anteriorly; with 4–6 coarse spine-like setae. Metaventrite with posteromedial oval glabrous area ca. twice as long as wide; length of glabrous area about two-thirds length of metaventrite. Procoxae with fine short pubescence and set with coarse, short spine-like setae; grouped on basal half. Meso- and metafemora with scattered punctures bearing short thickened, spine-like setae.

Abdomen. Ventrites covered with scattered, sparsely distributed setae of varying lengths; ventrites 1–4 with scattered, long setae, distinctly longer than longest setae on metaventrite, ventrite 5 more densely pubescent ( Fig. 7b View FIGURE 7 ). Aedeagus: outer margin of parameres sinuous, gradually tapering to apex, not curving inward; inner margin, straight, tapering from distal half (dorsal view); median lobe shorter than parameres, without apical hook. Gonopore located at four-fifths of median lobe. Basal piece tapered ( Fig. 11f View FIGURE 11 ).

Etymology. The specific epithet ovalis (L.), refers to the "egg-shaped" body. To be treated as a noun in apposition.

Distribution. Brazil (Minas Gerais) ( Fig. 14 View FIGURE 14 ).

Remarks. This species shares distinguishable diagnostic features with O. caparao and O. ecolab sp. n.: nonpale abdominal ventrites, elytral suture not raised, elytra surface with rows of systematic punctures bearing short setae. However, O. caparao differs from O. ovalis sp. n. by elytral surface with very shallowly impressed longitudinal grooves near the suture and by the prosternum set with six spine-like setae, in most specimens. O. ecolab sp. n. differs from O. ovalis sp. n. by a row of rounded black [=without sheen] spots along elytral suture and two small circular pale spots on each elytron.


Departamento de Geologia, Universidad de Chile


Instituto Nacional de Pesquisas da Amazonia


University of Kansas - Biodiversity Institute













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