Seven new species of the spider genus Matta Crosby from caves in the State of Minas Gerais, Brazil (Araneae, Tetrablemmidae)
Author
Brescovit, Antonio D.
Author
Cizauskas, Igor
text
Zootaxa
2019
2019-02-21
4559
3
401
444
journal article
27445
10.11646/zootaxa.4559.3.1
2dac93f3-40be-45f8-ba84-10026f56a001
1175-5326
2627047
10CDA291-A32F-4954-9B80-E33579AF46E3
Matta humrrum
sp. n.
Figures 19
̄21, 30B.
Types.
Male
holotype
and female
paratype
from Cave MOC-N3 (
44°01'21''W
19°33'01''S
), Matozinhos,
Minas Gerais
,
Brazil
,
04-15/IV/2011
, F.P. Franco & C.A.R. Souza
et al
. col., deposited in IBSP 186422.
Other material examined.
Brazil
.
Minas Gerais
:
Matozinhos
,
Cave
MOC-117 (
44°1'7''W
19°33'0''S
),
01-08/ VIII/2011
,
1♀
(
IBSP
180287
)
;
Cave
MOC-N3 (
44°1'21''W
19°33'1''S
),
01-08/VIII/2011
,
3♀
(
IBSP 180
288;
SEM
)
;
Cave
MOC-30 (
44°1'6''W
19°33'2''S
),
08-18/II/2011
,
1♀
(
IBSP 186419
)
;
Cave
MOC-30 (
44°1'6''W
19°33'2''S
),
08-18/II/2011
,
1♀
(
IBSP 186421
)
,
all collected by
F. P. Franco
& C.
A. R. Souza
et al
. col.;
Barão de Cocais
,
Cave
BRU_034,
X/2013
,
Ativo Ambiental
col.,
2♀
1 imm. (
IBSP 186376
)
;
Caeté
,
Cave
AP_064 (
43°40'10''W
20°0'37''S
),
31/V-05/
VI
/2012
,
R. Bessi
et al
. col.,
1♂
(
IBSP 186428
)
;
Itabirito
,
Mina do Pico
,
Cave
MP
,
M.P.A. Oliveira
col.,
1♀
(
IBSP 182515
)
;
1♂
2♀
(
IBSP 182519
;
SEM
)
;
1♀
(
IBSP 182523
)
;
2013,
M.P.A. Oliveira
col.,
1♂
(
IBSP 186396
; photo)
;
Cave
MP
_008 (
20°12'38''S
;
43°51'11''W
),
20/X/2011
,
Equipe Carste
col.,
1♀
(
IBSP 186393
; photo)
;
Mariana
,
Cave
SPA_03 (
20°17'48''S
;
45°36'46''W
),
12/V/2011
,
UFLA
col.,
1♂
(
IBSP 196147
)
;
Cave
SPA_16 (
20°17'43''S
;
45°37'5''W
),
8/V/2011
,
UFLA
col.,
1♂
(
IBSP 196148
)
;
Pedro Leopoldo
,
Cave
HOLC
_0025 (
19°34'43''S
;
44°00'59''W
),
22/VII-18/VIII/2015
,
Equipe Carste
col.,
1♀
(
IBSP 186506
)
;
Rio Acima
,
Cave
VG-26 (
43°53'55''W
20°6'60''S),
29/III-01/IV/2011
,
R. Andrade
&
I. Cizauskas
et al
. col.,
1♀
(
IBSP 179522
)
;
Cave
VG-26 (
43°53'55''W
20°6'60''S),
29/III-01/IV/2011
,
R. Andrade
&
I. Cizauskas
et al
. col.,
1♀
(
IBSP 179523
)
;
Santa Bárbara
,
Cave
APOL
_0001 (
43°39'56''W
20°0'35''S
),
21-25/XI/2011
,
R. Bessi
et al
. col.,
1♀
(
IBSP 186425
)
.
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 “yes”, and in this case indicates that this species is blind.
Diagnosis.
Matta humrrum
is distinguished from other
Matta
species by having a combination of leg I of male with retrolateral projection on a pedunculated base, with four conspicuous setae in sturdy sockets (
Fig. 20E
̄F), piriform dorsal fold of the uterus externus in females (
Fig. 19F
) and total absence of eyes (
Fig. 20A, C
) in both sexes.
Description.
Male
(
holotype
, IBSP 186422). Carapace, chelicerae, labium, endites, sternum and abdomen orange. Legs yellowish white (
Fig. 19A
). Total length 1.48. Carapace projected, 0.64 long, 0.5 wide, with rugose surface (
Fig. 20A
̄C). Sternal surface tenuously reticulate. Clypeus long and oblique (
Fig. 20C
). Eyes absent (
Fig. 20A
̄C). Cheliceral apophysis short, conic, projected down, with long hairs and translucent median lamina (
Fig. 20B
̄D, G). Leg measurements: I—femur 0.58/ patella 0.18/ tibia 0.42/ metatarsus 0.28/ tarsus 0.33/ total 1.79; II—0.52/ 0.16/ 0.4/ 0.27/ 0.28/ 1.63; III—0.44/ 0.15/ 0.34/ 0.23/ 0.28/ 1.44; IV—0.55/ 0.16/ 0.53/ 0.37/ 0.32/ 1.93. Leg formula 4123. Leg spination absent; metatarsus narrowed at base (
Fig. 20E
).
Abdomen
ovoid, large sclerotized plate covering dorsal surface (
Fig. 20E
); 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, and a line of the four epiandrous spigots.
Male palp:
femur with three long setae, median short and small number of projected plates; tibia strongly swollen, rounded posteriorly; cymbium small; bulbus pear-shaped, with conductor with elevated and sinuous border, involving the base of the embolus long, sinuous, and enlarged at apex, with acute and relatively short basal laminar projection, with enlarged base (
Figs 20G
̄H, 21 ĀB).
FIGURE 19
.
Matta humrrum
sp. n.
, male IBSP 186396 (
A–C
), female IBSP 186393 (
D‒F
)
A
habitus, dorsal view
B
palp, prolateral view
C
same, retrolateral view
D
habitus, dorsal view
E
abdomen, ventral view
F
vulva, cleared, dorsal view.
FIGURE 20
.
Matta humrrum
sp. n.
, male IBSP 182519 A carapace, frontal view
B
chelicerae, frontal view
C
carapace, lateral view
D
chelicerae, detail, lateral view
E
leg I, prolateral view
F
same, prolateral view
G
chelicerae, projection, detail, dorsal view
H
male palp, frontal view.
FIGURE 21
.
Matta humrrum
sp. n.
, (
A‒B
) male IBSP 182519 (C̅H) female IBSP 180288 A palp, prolateral view
B
same retrolateral view
C
carapace, frontal view
D
chelicerae, detail, frontal view
E
carapace, lateral view
F
abdomen, lateral view
G
same, ventral view
H
same, vulva plate, ventral view.
Female
(IBSP 186422). Coloration pattern as in male (
Fig. 19D
). Total length 1.49. Carapace as in male, 0.62 long, 0.47 wide. Eyes absent, and clypeus and sternum as in male (
Fig. 21C
̄E). Chelicerae with very small boss, next to border of carapace, with ventral translucent hyaline keel, as in male (
Fig. 21D
). Leg measurements: Ifemur 0.52/ patella 0.16/ tibia 0.41/ metatarsus 0.29/ tarsus 0.31/ total 1.69; II—0.45/ 0.14/ 0.37/ 0.26/ 0.31/ 1.53; III—0.42/ 0.15/ 0.33/ 0.24/ 0.26/ 1.4; IV—0.57/ 0.15/ 0.53/ 0.36/ 0.32/ 1.93. Leg formula 4123. Leg spination absent. Pedipalpal tarsus ending in acuminate, smooth pit.
Abdomen
with plates as in male (
Fig. 21 F
̄G). Vulvae externally with large ᴗ-shaped receptacle (
Fig. 19E
); narrow post genital plate and wide copulatory opening (
Fig. 21H
). Internally with sharp receptaculum and large copulatory ducts; central process oval, distally coiled, with half-length of the receptaculum (
Fig. 19F
).
Natural history
.
Matta humrrum
sp. n.
is the only species described in this paper that completely lacks eyes. Specimens were collected mainly in iron caves in the Quadrilátero Ferrífero Iron Region. Individuals were found in deep regions of the caves under stones on the cave floor. We hypothesize that this species is a troglobite.
Distribution.
Known only from caves in the State of
Minas Gerais
,
Brazil
(
Fig. 30B
).