Matta humhum,

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: 416-422

publication ID

https://doi.org/10.11646/zootaxa.4559.3.1

publication LSID

lsid:zoobank.org:pub:10CDA291-A32F-4954-9B80-E33579AF46E3

persistent identifier

http://treatment.plazi.org/id/038887C8-E765-FF98-FF0D-D53EFE901FB7

treatment provided by

Plazi

scientific name

Matta humhum
status

sp. n.

Matta humhum  sp. n.

Figures 10View FIGURE 10 ̄14, 30C.

Types. Male holotype and female paratype from Cave AP_066 (43°40'17''W 20°0'32''S), Caeté, Minas Gerais, Brazil, 12-21/XI/2009, R. Bessi et al. col., deposited in IBSP 179486 and IBSP 179487, respectively.

Other material examined. Brazil. Minas Gerais: Caeté, Cave AP_049 (43°41'29''W 20°2'8''S), 12-21/XI/ 2009, R. Bessi et al. col., 1♀ ( IBSP 179488View Materials)GoogleMaps  ; Cave AP_038 (-43.67925100 -20.03098600), epygean, 07-13/VIII/ 2012, R. Andrade & G. P. Perroni et al. col., 1♂ ( IBSP 186423View Materials)  ; Cave AP_049 (43°41'29''W 20°2'8''S), 31/V-05/ VI /2012, R. Bessi et al. col., 1♂ 1 ♀ ( IBSP 186427View Materials; photo)GoogleMaps  ; Cave AP_066 (43°40'17''W 20°0'32''S), 31/V-05/ VI / 2012, R. Bessi et al. col., 1♂ ( IBSP 186429View Materials)GoogleMaps  ; Barão de Cocais , Cave  RF _009 (43°29'13''W 19°55'6''S), 926 m, 10- 21/III/2 0 0 9, 2♀ ( IBSP 186411View Materials)GoogleMaps  ; Cave   RF _058 (43°41'8''W 20°1'34''S), 1342 m, 10-21/III/2009, 1♂ ( IBSP 186414View Materials)GoogleMaps  ; Cave   RF _005 (43°29'10''W 19°55'3''S), 948 m, 10-21/III/2009, 1♂ ( IBSP 186415View Materials)GoogleMaps  , all collected by R. Andrade et al.; Cave RF _057 (43°41'8''W 20°1'34''S), 1331 m, 22/VI-03/VII/2009, R. Bessi et al. col., 1♀ ( IBSP 186412View Materials)GoogleMaps  ; Cave   RF _069 (43°40'9''W 20°0'35''S), 1502 m, 09-13/XII/2009, R. Bessi et al. col., 1♂ ( IBSP 186413View Materials)GoogleMaps  ; Itabirito, Mina do Pico , 2013, 1♂ 1♀ ( IBSP 186394View Materials, IBSP 186395View Materials, IBSP 186397View Materials)  ; Mariana, Cave GER_0052 (20°17'25''S; 43°22'26''W), 15/IX-01/X/2015, 1♀ ( IBSP 186517View Materials)GoogleMaps  ; Cave SM _63 (20°13'51''S; 43°23'44''W), 11-23/ VIII/2014, 1♂ ( IBSP 186518View Materials)GoogleMaps  ; Cave SM _82A (20°13'38''S; 43°27'43''W), 30/IX-04/X/2013, 2♀ ( IBSP 186519View Materials SEM 1 ♀)GoogleMaps  , all collected by Eq. Carste col.; Cave SM, 13/XII/2012, 1♀ ( IBSP 189177View Materials)  ; Cave FN-012 (43°26'19''W 20°12'29''S), 18/XII/2012, 1♂ ( IBSP 189178View Materials)GoogleMaps  ; Cave FN-010 (43°26'19''W 20°12'27''S), 09/XII/2012, 1♂ ( IBSP 189179View Materials)GoogleMaps  , Cave FN-012 (43°26'19''W 20°12'29''S), 09/XII/2012, 1♂ 3♀ ( IBSP 189180View Materials)GoogleMaps  , all collected by BioEspeleo Consultoria Ambiental; Cave FN_12 (20°12'29''S; 43°26'19''W), 16-21/I/2009, 1♂ ( IBSP 146209View Materials)GoogleMaps  ; Cave FN_15 (20°12'20''S; 43°26'9''W), 5-9/V/2009, 1♂ ( IBSP 146258View Materials)GoogleMaps  ; Cave FN_07 (20°12'37''S; 43°26'21''W), 5-9/V/2009, 1♂ ( IBSP 146179View Materials — SEM ♂)GoogleMaps  ; Cave FN_20, 3-7/II/2011, 1♂ ( IBSP)  , all collected by R. Andrade; Santa Bárbara, Cave APOL _28 (43°40'8''W 20°0'56''S), 30/VI-08/VII/2011, R. Bessi et al. col., 1♀ ( IBSP 186424View Materials)GoogleMaps  ; Cave APOL _28 (43°40'8''W 20°0'56''S), 05-09/XII/2011, R. Bessi et al. col., 1♂ ( IBSP 186426View Materials)GoogleMaps  .

Etymology. The specific name is a noun in apposition that refers to an expression used by people in the Brazilian State of Minas Gerais meaning “no”, and in this case indicates that the species is not blind but has vestigial eyes.

Diagnosis. Matta humhum  is distinguished from other Matta  species by having a combination of males with a leg I with retrolateral projection on a raised base, with four conspicuous setae in elevated sockets in the male ( Fig 12AView FIGURE 12 ̄D) and mushroom shape dorsal fold of the uterus externus in females ( Fig. 10FView FIGURE 10).

Description. Male (Holotype, IBSP 179486). Cephalothorax and abdomen orange. Legs and pedipalps yellow ( Fig. 10AView FIGURE 10). Total length 1.07. Carapace projected, 0.47 long, 0.4 wide, with rugose surface ( Fig. 11A, CView FIGURE 11). Sternal surface tenuously reticulate. Clypeus long, oblique, four times the diameter of the vestigial eyes ( Fig. 11AView FIGURE 11). Eye almost vestigial, diameters and interdistances: AME 0.04, AME-AME 0.08 ( Figs. 10AView FIGURE 10, 11AView FIGURE 11). Cheliceral apophysis short, conical, in the middle area, with long hairs and translucent median lamina ( Fig. 11BView FIGURE 11 ̄C). Leg measurements: I—femur 0.36/ patella 0.13/ tibia 0.28/ metatarsus 0.17/ tarsus 0.23/ total 1.17; II—0.32/ 0.13/ 0.24/ 0.16/ 0.18/ 1.03; III—0.26/ 0.12/ 0.2/ 0.16/ 0.2/ 0.94; IV—0.42/ 0.12/ 0.31/ 0.22/ 0.23/ 1.3. Leg formula 4123. Leg I, spination absent; metatarsus narrowed at base ( Fig. 12AView FIGURE 12 ̄D). Trichobothria as in M. zuiuda  ( Fig. 12EView FIGURE 12). Abdomen ovoid, large sclerotized plate covering dorsal surface ( Fig. 11DView FIGURE 11); ventrally covered by four sclerotized plates ( Fig. 11EView FIGURE 11). Abdominal plates: large pulmonary plate with rounded anterior margin, surrounding pedicel and bearing oval book-lung plates, followed posteriorly by very narrow postgenital plate, suboval preanal plate, and conical anal plate surrounding spinnerets; laterally with four pairs of narrow plates, with same length ( Fig. 11DView FIGURE 11), and a line of the four epiandrous spigots ( Fig. 11FView FIGURE 11). Male palp with femur with three long setae, median short and projected salient plates ( Fig. 12FView FIGURE 12); tibia strongly swollen, rounded posteriorly; cymbium small; bulbus pear-shaped, with conductor with short border, involving the base of the embolus long, curved in the posterior third area and enlarged at apex, with acute and short basal laminar projection ( Fig. 13AView FIGURE 13 ̄F).

Female (Paratype, IBSP 179487). Coloration pattern as in male ( Fig. 10DView FIGURE 10). Total length 1.15. Carapace slightly most projected that in male, with long median dorsal setae and fovea with 4-5 small rounded projections ( Fig. 14AView FIGURE 14 ̄E); 0.47 long, 0.38 wide. Clypeus and sternum as in male. Eye diameters and interdistances as in male. Chelicerae without apophysis, with ventral translucent hyaline keel as in male ( Fig. 14AView FIGURE 14). Leg measurements: Ifemur 0.36/ patella 0.12/ tibia 0.26/ metatarsus 0.16/ tarsus 0.23/ total 1.13; II—0.32/ 0.11/ 0.23/ 0.15/ 0.22/ 1.03; III—0.23/ 0.11/ 0.19/ 0.16/ 0.2/ 0.89; IV—0.38/ 0.12/ 0.32/ 0.2/ 0.21/ 1.23. Leg formula 4123. Leg spination absent. Pedipalpal tarsus ending in acuminate, smooth pit ( Fig. 14FView FIGURE 14). Abdomen with plates as in male ( Fig. 14GView FIGURE 14). Vulvae externally with ᴗ-shaped receptacle, visible by transparency ( Fig. 10EView FIGURE 10); narrow post genital plate and thin copulatory opening ( Fig. 14HView FIGURE 14). Internally with enlarged receptaculum and narrow at base copulatory ducts; central process narrow, with length of the receptaculum ( Fig. 10FView FIGURE 10).

Natural history. Matta humhum  sp. n. is a species known only from caves in the ferruginous formations of the Quadrilátero Ferrífero Iron Region. Specimens were collected in both aphotic and twilight zones and always on the cave floor. Based on reduced eyes and long hairs of trichobothria we hypothesize that this species is a troglobite.

Distribution. Known from caves in Quadrilátero Ferrífero Iron Region in the State of Minas Gerais, Brazil ( Fig. 30CView FIGURE 30).

VI

Mykotektet, National Veterinary Institute

SM

Sarawak Museum

IBSP

Instituto Biologico de Sao Paulo

Kingdom

Animalia

Phylum

Arthropoda

Class

Arachnida

Order

Araneae

Family

Tetrablemmidae

Genus

Matta