Metopioxys carajas Asenjo, 2019

Asenjo, Angélico, Pietrobon, Thadeu & Ferreira, Rodrigo Lopes, 2019, A new troglobitic species of Metopioxys (Staphylinidae: Pselaphinae) from Brazilian iron ore caves, Zootaxa 4576 (1), pp. 195-200 : 196-200

Metopioxys carajas Asenjo sp. nov.

( Figs. 1–15 )

Type material ( 3 ♂♂, 3 ♀♀). Holotype: BRAZIL: ♂, labeled “Gruta N4E 10— FONA Carajás -PA // 20.x [October]- 01.xi [November] [20]06 Andrade et al col [back side write N4E-10, left elytrum and right protibia and protarsi missing]”, “Carste(Coleo) 0904”, “Tubo 40-Olhos s/pigmento // Antenas e pernas grandes”, “12”, “VII”, “ Metopioxys // sp. nov. // Det. A. Asenjo, 2014”, “ HOLOTYPE ♂ / Metopioxys / carajas Asenjo sp. nov. / Desig. Asenjo et al., 2018” ( CEMT).

Paratype: (2 ♂♂, 3 ♀♀), labeled: “Gruta N5S20—Flona Carajás –PA[Pará state] // 0596664mE/9327035mN SAD’69 // 25.viii [August]- 3.ix [September].09 R. Andrade et all col. [back side write 117]”, “ Pselaphinae sp18”, “ Metopioxys // sp. nov. // Det. A. Asenjo, 2014” [Male]. “Gruta N5S20—Flona Carajás –PA[Pará state] // 0596664mE/9327035mN SAD’69 // 25.viii [August]- 3.ix [September].[20]09 R. Andrade et all col.[back side write 118, meso and metatarsi missing]”, “ Pselaphinae sp8”, “ I38 ”, “ Metopioxys // sp. nov. // Det. A. Asenjo, 2014” [Male]. “Gruta N5S10—Flona Carajás –PA[Pará state] // 596113mE/9325034mN SAD’69 // 14- 23.x [October].[20]09 R. Andrade et all col. [back side write 482. Right maxilar palpi, left elytra and right metatarsi, left metaleg are missing]”, “ Pselaphinae sp8”, “ I39 ”, “ Metopioxys // sp. nov. // Det. A. Asenjo, 2014” [Female]. “Gruta N5S85—Flona Carajás –PA[Pará state] // 0596684mE/9327144mN SAD’69 // 25.viii [August]- 03.ix [September].[20]09 R. Andrade et all col. [back side write 73]”, “ Pselaphinae sp8”, “ Metopioxys // sp. nov. // Det. A. Asenjo, 2014” [Female]. “Gruta N4E21—Flona Carajás –PA[Pará state] // 0592943mE/9332978mN SAD’69 // 20.iv-04.v. [20]10 R. Andrade et al col.[back side write 905, right metarsus is missing]”, “ Pselaphinae sp8”, “ Metopioxys // sp. nov. // Det. A. Asenjo, 2014” [Female]. All paratypes with label “ PARATYPE / Metopioxys / carajas Asenjo sp. nov. / Desig. Asenjo et al., 2018” and are deposited in ISLA .

Diagnosis. Metopioxys carajas sp. nov. is different from the other known species based on the shape of the aedeagus ( Figs. 7–9 ) and the lack of eyes ( Fig. 3 ).

Description. Holotype male, BL: 1.95. Body, mouthparts, antennae, and tarsi reddish light-brown ( Figs. 1–2 ).

Head ( Figs. 1, 5 ): pyriform (HL: 0.50; HW: 0.32), anterior region distinctly narrower, slightly raised at antennal tubercle. Posterior margin of head abruptly narrowed and with posterior-lateral angles rounded. Neck almost 3/4 width of head, and lateral margins straight ( Figs. 1, 5–6 ). Head with two vertexal foveae [VF] ( Figs. 1, 5 ) near posterior margin. Vertex longitudinally impressed with sulcus running from anterior margin of antennal tubercle to one fovea on vertex; sulcus wider on central disk on vertex around the fovea on vertex. Ventral surface of head ( Fig. 6 ) with long gular sulcus widening towards neck, interrupted at posterior third by curved sulcus that connected two gular foveae [GF]. Compound eyes absent ( Figs. 1–2, 3, 5 ). Antennae ( Figs. 1–2, 4 ) longer than body length, scape almost half antennal length, last three antennomeres abruptly widened, scape length (all lengths without peduncle) 0.97 mm, width 0.07 mm, pedicel shorter than scape (length 0.17: width 0.05), antennomeres 3 to 7 longer than wide: 3 (length 0.30: width 0.04), 4 (length 0.07: width 0.04), 5 (length 0.13: width 0.04), 6 (length 0.06: width 0.04), 7 (length 0.09: width 0.04); antennomere 8 subquadrate (length 0.04: width 0.04), antennomere 9 longitudinally oval (length 0.10: width 0.07), antennomere 10 almost subquadrate (length 0.07: width 0.10), antennomere 11 longitudinally oval with pointed apex (length 0.15: width 0.10); all antennomeres covered by long setae.

Thorax ( Figs. 1, 5 ): pronotum cordiform (PL: 0.39; PW: 0.30) widest at middle. Pronotum convex, with spine on each anterolateral, two rounded protuberance on anterior half and two small rounded protuberance on posterior half of pronotum, with lateral antebasal foveae [LAF]. Pronotum with anterior and basal margins convex. Prosternum with lateral procoxal fovea [LPCF]. Mesoventrite with prepectal fovea [PPF] and lateral mesosternal fovea [LMSF]. Metaventrite with lateral mesocoxal foveae [LMCF], lateral metasternal fovea [MLTF] and median metasternal fovea [MMTF]. Region of metaventrite in articulation with metacoxae like to rounded protuberance.

Elytra: subquadrate (EL: 0.55; EW: 0.53), sides gradually broadening apically ( Fig. 1 ). Posterior margins convex, humeri with small longitudinal carina with small tooth. Elytron [left elytra is missing] with two basal elytral foveae [BEF] at anterior margin, one close to elytral suture, second fovea smaller and located at middle of elytral base. Apicolateral margin of elytra slightly notched. Flight wings weakly developed.

Legs ( Figs. 1–2 ): legs long and slender. Femora thickened at apical half. Tibiae slightly curved and similar in length to femora, all tibiae thickened at apex. Protibiae in its internal face carinate and without microsetae on posterior and mesial region. Tarsi 3-segmented, first tarsomeres very short, last 2 tarsomeres longer, tarsomere 2 longer that segment 3; all tarsi with single claw and minute accessory seta. Procoxae conical and prominent, mesocoxae globular-conical and prominent, metacoxae transverse, region that articulates with meta-trochanter conical. Procoxae and mesocoxae contiguous, metacoxae widely separated.

Abdomen ( Figs. 1–2 ): slightly margined, with five visible tergites (morphological tergites IV–VIII), tergite VIII with rounded apex. Tergites and sternites IV–VII fused and bordered by fine carina. Sternite III visible as small transverse plate between metacoxae with long transversal sulcus. Sternite VIII ( Figs. 10–11 ) emarginated with small prolongation on apical half, apex with long setae. Sternum IX divided longitudinally ( Figs. 12–13 ).

Aedeagus: asymmetric, median lobe slightly bulbous at base ( Figs. 7–9 ).

Female with characters of head, pronotum, and elytra as are described for males. Abdominal sternum VIII with posterior margin rounded and without small prolongation.

Habitat and ecological notes. The specimens were collected in humid environments, under rocks on aphotic zone in five caves (N4E_0010, N4E_0021, N5S_0010, N5S_0020, and N5S_0085). The caves are located in the Serra Norte Geomorphological Unit ( Valentim & Olivito 2011). The mountain range has a plateau on top, the slopes have gradual (20 to 40%) to steep inclines (45 to 100%), and the caves are at an elevational range of between 600 to 700m ( Fig. 14 ).

The predominant vegetation is the Submontane Open Ombrophylous Forest with vines ( Veloso et al. 1991). The vegetation is constituted by an open forest formation with presence of cipó commonly known as “lianas” ( Fig. 15 ).

Etymology. The specific epithet name “Carajas” refers to the locality “Serra dos Carajás” where the specimens were collected. This is a noun in apposition.

Distribution. Known from five iron-rich caves located in the “Serra dos Carajás” west to the municipality of Marabá, Pará state, Brazil ( Fig. 14 ).

Comments. The new species belongs to Metopioxys , based on the long spine on each side of the pronotum ( Figs. 1, 5 ), and third antennomere longer than second ( Fig. 4 ) ( Raffray 1908, Park 1942). The new species is included in the gladiator species-group defined by Comellini (1983), which is characterized by the presence of one spine on each side of pronotum ( Figs. 1, 5 ), and one small tooth on the humeral region of the elytra.

Figures

FIGURE 14. Map where the specimens of Metopioxys carajas sp. nov. were collected. The code numbers on the map represent the names of the caves.

FIGURE 15. The entrance and vegetation around the caves. The code numbers represent the name of the caves.

FIGURES 1–13. Metopioxys carajas new species, holotype, 1, habitus, dorsal view; 2, habitus, left lateral view; 3, head, left lateral view; 4, left antenna, lateral view; 5, head and pronotum, dorsal view; 6, head and pronotum, ventral view; 7, aedeagus, ventral view; 8, aedeagus, lateral view; 9, aedeagus, dorsal view; 10, segment VIII (T8, tergum VIII and S8, sternum VIII), lateral view; 11, sternum VIII (S8), ventral view; 12, tergum IX left plate, ventral view; 13, tergum IX right plate, ventral view. Scale bars: 1 mm (1–2); 0.5 mm (4–6); 1 mm (3, 7–13).