Coarazuphium xingu Pellegrini, Ferreira & Vieira, 2022

Pellegrini, Thais Giovannini, Ferreira, Rodrigo Lopes, Zampaulo, Robson de Almeida & Vieira, Leticia, 2022, Three new troglobitic Coarazuphium (Coleoptera, Carabidae, Zuphiini) species from a Brazilian hotspot of cave beetles: exploring how the environmental attributes of caves drive ground-beetle niches, Subterranean Biology 43, pp. 97-126 : 97

Coarazuphium xingu Pellegrini, Ferreira & Vieira sp. nov.

Figs 29-32 , 33-38

Type material.

Holotype: Brazil: Pará, São Félix do Xingu, Cave SFX-0057, 6°24'06.2"S, 51°54'08.1"W, ♂, 03.II.2018, Ativo Ambiental leg. (ISLA 75762).

Paratype: the same locality as for holotype, 1 ♀, 20.VII.2018, Ativo Ambiental leg. (ISLA 65430).

Etymology.

The epithet Coarazuphium xingu is given in designation to the type locality, where the two known specimens were collected. Xingu is an indigenous word that means "good and clean water" and names one of the main rivers in the region and an important indigenous reserve, the Parque Indigene do Xingu, currently the largest indigenous reserve in Brazil and one of the most important barriers to advanced agricultural development in the Amazon.

Differential diagnosis.

All characteristics of C. xingu sp. nov. are consistent with the description of the genus Coarazuphium . This species differs from all others of the genus by the following combination of characters: elytral outline subparallel, elytra with maximum width in the posterior half, with a very slight subapical sinuosity; location of setigerous punctures on the head dorsally: one anterior supraorbital and one postocular; antennae not very long, about 0.68 times as long as body length; metafemur without a spine medially at the ventral side.

Description.

Size and proportions. OBL: 3.26 mm ♂, 3.19 mm ♀, EW: 1.09 mm ♂, 1.10 mm ♀, HW/PW: 1.07 ♂, 1.10 ♀.

Habitus. Body with uniform pale to dark brown color (Fig. 30 ).

Integument. Dorsally covered with short recumbent hairs.

Head. Subtrapezoidal (Fig. 30 ), HW/HL: 0.91 ♂, 0.96 ♀. Head almost as wide as pronotum. Location of setigerous punctures on the head dorsally: one pair of anterior supraorbital above the eyes and one pair of postocular; head is covered with a fine pubescence more densely distributed on the vertex margin; ventrally are three pairs of setae on the post-gena located apically and a fine pubescence on the gula (Fig. 29 ). Eyes reduced, depigmented, and flattened, situated laterally at the end of the genal sulcus, ommatidia are not visible at 50 × (Fig. 29 ). Antennae filiform and flagellar (Fig. 30 ), AL: 2.21 mm ♂, 2.11 mm ♀, AL/PL: 3.74 ♂, 3.67 ♀, A1L/A2-4L: 0.76 ♂, 0.75 ♀. First antennomere (scape) with a long seta distally close to the apical portion, and a row of several semi-erect setae; 2nd one very short. Antennal segments 3-10 subequal, rectangular, and almost round in cross-section, except for the tip of the terminal antennomere, which is laterally flattened.

Prothorax. Pronotum trapezoidal, PL/PW: 0.75 ♂, 0.79 ♀ (Figs 29 , 30 ). Maximum pronotum width closely behind the anterior margin, which is almost as wide as head. Anterior angle rounded. Posterior angle acute. Dorsal surface with two pairs of lateral marginal erect setae: one close to the antero-lateral angles, and the other shorter, close to the postero-lateral angles. Prosternum with a pair of submedial setae (Fig. 32 ).

Pterothorax. Metasternum longer than wide. Metepisternum wider than long.

Elytra and hind wings. Elytra free (Fig. 30 ), EL/EW: 1.60 ♂, 1.62 ♀. Elytral outline subparallel, maximum elytral width in the posterior half, EW/PW: 1.39 ♂, 1.50 ♀. Subapical elytral sinuosity very slight. Elytral chaetotaxy: no discal setae present; the umbilicate series of the 8th stria with seven large setae (about 0.58 times as long as elytra) on each elytron: three close to the anterior angle, two marginal in the lateral posterior half, and two on the posterior margin. Hind wings very reduced (Fig. 31 ), 0.10-mm long, HWL/EL: 0.06 ♂.

Legs. Profemur 1.21 (♂) and 1.12 (♀) times as long as mesofemur, and 0.84 (♂) and 0.76 (♀) times as long as metafemur, respectively. Protibia 1.23 (♂) and 1.05 (♀) times as long as mesotibia, and 0.79 (♂) and 0.75 (♀) times as long as metatibia, respectively. Protibia 1.28 (♂) and 1.20 (♀) times as long as protarsus, mesotibia 0.81 (♂) and 0.97 (♀) times as long as mesotarsus, and metatibia 0.93 (♂) and 1.01 (♀) times as long as metatarsus, respectively. First pro-, meso-, and metatarsomere each almost equal to tarsomeres 2-4 combined. Length of protibia and protarsus combined 2.04 (♂) and 2.01 (♀) times as long as pronotum, length of mesotibia and mesotarsus 2.09 (♂) and 2.11 (♀) times as long as pronotum, while length of metatibia and metatarsus 2.99 (♂) and 2.91 (♀) times as long as pronotum, respectively.

Abdomen. Ventrites 2-7 with a very fine pubescence. Seventh ventrite with a pair of small ventral setae at its posterior margin. Male genital segment triangular, GSL: 0.65 mm, GSW: 0.38 mm.

Aedeagus. Median lobe of aedeagus slightly curved ventrally and elongate, narrowed apically, apical margin rounded (Figs 33-35 ), MLA: 0.58 mm, OML: 0.15 mm. Left paramere subtriangular, conchoid, about twice as long as wide, LPL: 0.21 mm; right paramere styliform, about three times as long as wide, distinctly shorter than the left one, RPL: 0.15 mm.

Female reproductive tract. Ovipositor (Figs 37 , 38 ): with a broad laterotergite; basal gonocoxite 1 longer than apical gonocoxite 2, with two small and three long trichoid setae apicoventrally; gonocoxite 2 strongly curved, falciform in lateral aspect, with notched apex, with preapical setose organ circuloid ventrally, with four nematiform setae, laterodorsal surface with many marginal pit pegs medially (on the lateroventral surface, the marginal pit pegs are located more apically). Female genital tract totally membranous (Fig. 36 ). Bursa copulatrix bulbous, expanded in the bursal saculus anteriorly to the insertion point of common oviduct, which is curved basally and partially broken. Spermatheca, spermathecal gland duct, and spermathecal gland were broken and were not represented or visualized. No secondary spermathecal gland observed.

Distribution.

The species was found in a single cave located in the municipality of São Felix do Xingu, state of Pará, Brazil (Figs 2 , 4 , 5 ).

Figures

Figures 29 - 32. Coarazuphium xingu sp. nov., external morphology 29 head and prothorax, lateral view 30 habitus, dorsal view 31 a detail on hind wings, dorsal view 32 prothorax, ventral view. Scale bars: 0.5 mm (30), 0.2 mm (29, 32); 0.1 mm (31).

Figures 33 - 38. Coarazuphium xingu sp. nov., male and female genitalia 33 aedeagus, left lateral view 34 aedeagus, dorsal view 35 aedeagus, right lateral view 36 female reproductive tract, dorsal view 37 gonocoxite, dorsal view 38 preapical setose organ, dorsal view bc bursa copulatrix co common oviduct gc 1 gonocoxite 1 gc 2 gonocoxite 2 hs helminthoid sclerite Lt laterotergite mpp marginal pit pegs pso preapical setose organ. Scale bars: 0.5 mm (36, 38); 0.125 mm (37); 0.1 mm (33 - 35).

Figures 2 - 7. Geographic distribution of C. xikrin sp. nov., C. kayapo sp. nov. and C. xingu sp. nov. 2 location of the caves with occurrences of the new species in the state of Para, Brazil and South America 3 Coarazuphium kayapo sp. nov., a living specimen 4 location of the caves (circles) where Coarazuphium species have been collected. Shaded regions correspond to the different highlands in the area 5 photograph of the Sao Felix do Xingu region, where is situated the type locality (Cave SFX- 0057) of C. xingu sp. nov. 6 photograph of the N 1 N 8 area from the Serra Norte highland, where most of caves with occurrences of C. xikrin sp. nov. are located 7 photograph of a lake found in the Serra Sul highland, where caves with occurrences of C. kayapo sp. nov. are located. Photo credits: Ativo Ambiental (3), Fundacao Casa de Cultura de Maraba (5), Marcelo Rosa (6), and Robson de Almeida Zampaulo (7).