Matta cambito, Brescovit & Cizauskas, 2019

Brescovit, Antonio D. & Cizauskas, Igor, 2019, Seven new species of the spider genus Matta Crosby from caves in the State of Minas Gerais, Brazil (Araneae, Tetrablemmidae), Zootaxa 4559 (3), pp. 401-444 : 422-427

Matta cambito sp. n.

Figures 15 ̄18, 30A

Types. Male holotype from Cave SMS_150 (20°12'S; 43°51'W), 03/XII/2015, and female paratype from Cave MP_008 (20°12'38''S; 43°51'11''W), 08/IX/2005, Mina do Pico, Itabirito, Minas Gerais, Brazil, R.L. Ferreira col., deposited in IBSP 186400 and IBSP 186399, respectively.

Other material examined. Brazil. Minas Gerais: Itabirito, Mina do Pico, Cave MP _008 (20°12'38''S; 43°51'11''W), 08/IX/2005, R.L. Ferreira col., 2♂ 1♀ ( IBSP 196166 , 1♂ 1♀ = SEM); Cave SMS_150 (20°12'S; 43°51'W), 03/XII/2015, R. L. Ferreira col., 1♀ ( IBSP 196167 — ♀ = SEM); Matozinhos, Cave MOC-113 (19°33'16''S; 44°01'12''W), 04-15/IV/2011, F.P. Franco & C.A.R. Souza et al. col., 1♂ ( IBSP 186420 ) .

Etymology. The specific name is a noun in apposition that refers to an interjection used by people in the Brazilian State of Minas Gerais meaning “legs long and thin”, due to the slender form of this species.

Diagnosis. Matta cambito is distinguished from other Matta species by having a combination of slender body and long legs in males and females ( Fig. 15A, D ), leg I of male with base of the three conspicuous setae in an elongated projection ( Fig. 17A ̄B) and subtriangular dorsal fold of the uterus externus of females ( Fig. 15F ).

Description. Male (holotype, IBSP 186400). Cephalothorax and abdomen yellow. Legs yellowish white ( Fig. 15A ). Total length 1.34. Carapace projected, 0.52 long, 0.32 wide, with rugose surface, four times the diameter of the vestigial eyes ( Figs 15A , 16A, C ). Sternal surface tenuously reticulate. Clypeus long, oblique ( Fig. 16C ). Eye almost vestigial ( Fig. 16A ̄C), diameters and interdistances: AME 0.04, AME-AME 0.08. Cheliceral apophysis short, conical, with long hairs and translucent median lamina ( Fig. 16A ̄D). Leg measurements: I – femur 0.46/ patella 0.15/ tibia 0.43/ metatarsus 0.31/ tarsus 0.36/ total 1.71; II—0.45/ 0.15/ 0.42/ 0.3/ 0.35/ 1.67; III—0.38/ 0.15/ 0.33/ 0.28/ 0.32/ 1.46; IV—0.61/ 0.16/ 0.52/ 0.38/ 0.35/ 2.02. Leg formula 4123. Leg I, spination absent; metatarsus narrowed at base ( Fig. 17B ). Abdomen ovoid, elongated, large sclerotized plate covering dorsal surface ( Fig. 15A ); ventrally covered by four sclerotized plates. Abdominal plates: large pulmonary plate with rounded anterior margin, surrounding pedicel and bearing oval book-lung plates, followed posteriorly by very narrow postgenital plate, rectangular preanal plate, and conical anal plate surrounding spinnerets, laterally with four pairs of narrow plates, with same length ( Fig. 16G ), and a line of the four epiandrous spigots ( Fig. 16H ). Male palp with femur with three long setae, median short and small number of projected salient plates ( Fig. 17H ); tibia strongly swollen, almost oval, rounded posteriorly; cymbium small; bulbus pear-shaped, with conductor with short border, involving the base of the embolus long, poor sinuous, and sharp at apex, with acute and relatively short basal laminar projection ( Fig. 17C ̄G).

Female (Paratype, IBSP 186399). Coloration pattern as in male, but darker ( Fig. 15D ). Total length 1.34. Carapace as in male, 0.56 long, 0.44 wide. Eyes, clypeus and sternum as in male. Chelicerae without apophysis, with ventral translucent hyaline keel as in male ( Fig. 18A ). Endites largeand serrula with 14-18 conical teeth ( Fig. 18C ). Labium subtriangular and more than 8 elongated setae ( Fig. 18C ). Leg measurements: I—femur 0.48/ patella 0.15/ tibia 0.47/ metatarsus 0.31/ tarsus 0.32/ total 1.73; II—0.45/ 0.14/ 0.41/ 0.3/ 0.34/ 1.64; III—0.35/ 0.11/ 0.34/ 0.32/ 0.3/ 1.42 IV—0.64/ 0.15/ 0.56/ 0.4/ 0.33/ 2.08. Leg formula 4123. Leg spination absent. Pedipalpal tarsus ending in acuminate, smooth pit ( Fig. 18B ). Abdomen with plates as in male ( Fig. 18D ̄E). Vulvae externally with ᴗ-shaped receptacle, visible by transparency ( Fig. 15E ); narrow post genital plate and enlarged copulatory opening ( Fig. 18F ). Internally with narrow receptaculum and copulatory ducts; central process narrow, with half-length of the receptaculum ( Fig. 15F ).

Natural history. Matta cambito sp.n. has reduced eyes, similar to those of other cave-adapted Matta species. It is known only from caves in the Quadrilátero Ferrífero Iron Region and one cave in carbonate formation. We hypothesize that this species is a troglobite.

Distribution. Known from caves in the State of Minas Gerais, Brazil ( Fig. 30A ).

Figures

FIGURE 15. Matta cambito sp. n., male IBSP 196166 (A–C), female IBSP 196166 (D‒F) A habitus, dorsal view B palp, retrolateral view C same, prolateral view D habitus, dorsal view E abdomen, ventral view F vulva, cleared, dorsal view.

FIGURE 16. Matta cambito sp. n., male IBSP 196166 A carapace, frontal view B chelicerae, frontal view C carapace, lateral view D same, detail chelicerae, lateral view E same, dorsal view F same, ocular area, detail, frontal view G abdomen, ventral view H same, epiandrous area, ventral view.

FIGURE 17. Matta cambito sp. n., male IBSP 196166 A leg I, prolateral view B same, ventral view (C‒G) male palp, C retrolateral view D detail, retrolateral view E ventral view F detail, ventral view G detail, frontal view H male palp tibiae, dorsal view.

FIGURE 18. Matta cambito sp. n., female IBSP 196167 (A–F), A chelicerae, frontal view B pedipalp, distal area C endites and labium, ventral view D abdomen, lateral view E same, ventral F same, vulva plate.

FIGURE 30. A Matta nuusga = pentagon white, M. cambito = yellow star; B M. teteia = red star, M. humrrum = pentagon blue, M. pititinha = yellow spangle; C M. zuiuda = close white circle, M. humhum = yellow square.