Loxosceles carinhanha Bertani, von Schimonsky & Gallao

Bertani, Rogerio, Schimonsky, Diego M. von, Gallao, Jonas E. & Bichuette, Maria E., 2018, Four new troglophilic species of Loxosceles Heinecken & Lowe, 1832: contributions to the knowledge of recluse spiders from Brazilian caves (Araneae, Sicariidae), ZooKeys 806, pp. 47-72: 47

publication ID

http://dx.doi.org/10.3897/zookeys.806.27404

publication LSID

lsid:zoobank.org:pub:6877DA0E-7A92-4EE2-8F33-7D05B337AE73

persistent identifier

http://treatment.plazi.org/id/F90FD902-CBA1-40A1-9B59-506D75D722D3

taxon LSID

lsid:zoobank.org:act:F90FD902-CBA1-40A1-9B59-506D75D722D3

treatment provided by

ZooKeys by Pensoft

scientific name

Loxosceles carinhanha Bertani, von Schimonsky & Gallao
status

sp. n.

Loxosceles carinhanha Bertani, von Schimonsky & Gallao  sp. n. Figs 1, 28-33, 34-36, 37-41

Material examined.

Male holotype ( MZUSP 74436) and female paratype ( MZUSP 74437), 1 female paratype ( MZUSP 74438), 1 female paratype (LES 14709), BRAZIL: Bahia, Carinhanha, Gruna Água Fina cave (13°41'S, 43°48'W) 484 m a.s.l., M.E. Bichuette, N. Hattori and J.E. Gallão leg., 29.v.2012.

Other material examined.

BRAZIL, Bahia: Carinhanha, Gruna Água Fina Cave (13°41'S, 43°48'W) 484 m a.s.l., 1 female and 2 immatures, M.E. Bichuette, N. Hattori and J.E. Gallão leg., 29.v.2012 ( MZUSP 74439).

Diagnosis.

Males of Loxosceles carinhanha  sp. n. can be distinguished from those of all other Loxosceles  species by the thick embolus (Figs 29-31), a strong curvature on basal metatarsus I, and a constriction on distal tibia I (Figs 34, 35). Females of L. carinhanha  sp. n. resemble females of L. cardosoi  sp. n. by having spermathecae as a large, weakly sclerotized pouch with two large receptacles on its distal portion. Females of L. carinhanha  sp. n. can be distinguished from those of L. cardosoi  sp. n. by the spermathecae lacking a sclerotized transverse plate and dorsal parts of bursa copulatrix having only a small sclerotized triangular area (Figs 39-41).

Description.

Male holotype: Total length 7.32. Carapace 3.63 long, 3.39 wide. Eye sizes and interdistances: ALE 0.22, PME 0.22, PLE 0.21, PME-PLE 0.05, PME-ALE 0.27; clypeus 0.38. Leg formula II, IV, III, I. Leg lengths: leg I: femur 7.18, patella 1.44, tibia 6.68, metatarsus 9.29, tarsus 2.18, total 26.77; II femur 9.69, patella 1.51, tibia 10.87, metatarsus 13.34, tarsus 2.23, total 37.64; III: 7.56, 1.33, 7.88, 9.97, 1.70, 28.44; IV: 8.37, 1.41, 8.54, 11.92, 2.16, 32.40. Palp: femur 1.92 long, 0.34 wide; patella 0.54 long, 0.41 wide; tibia 1.12 long, 0.57 wide; cymbium 0.61 long, 0.45 wide. Labium 0.89 long, 0.49 wide. Sternum 1.87 long, 1.74 wide. Femur I 1.9 times as long, tibia I 1.8 times as long and leg I 7.4 as long as carapace. Palpal femur 5.6 times longer than wide; tibia 2.0 times longer than wide; cymbium oval (Figs 32, 33). Bulb suboval and slightly larger than cymbium. Embolus thick and straight, with a curvature on apex, approximately 1.3 times longer than bulb length in retrolateral view, without carina (Figs 29-31). Femur I prolateral median area with a series of enlarged setae (Figs 34, 36). Metatarsus I strongly curved on its basal portion. Distal tibia I abruptly narrow, with a series of strong macrosetae before the constriction (Figs 34, 35). Cephalic region of carapace, fovea, and thoracic striae with long, greyish setae (Fig. 28). Carapace and chelicerae uniformly reddish (Fig. 28). Abdomen, legs, and palp light brown, covered by short, greyish setae. Coxae and sternum light brown; labium and endites slightly darker.

Female paratype: Total length 9.30. Carapace 3.99 long, 3.25 wide. Eye sizes and interdistances: ALE 0.20, PME 0.20, PLE 0.22, PME-PLE 0.05, PME-ALE 0.34; clypeus 0.41. Leg formula II, I, IV, III. Leg lengths: leg I: femur 6.79, patella 1.30, tibia 7.12, metatarsus 7.47, tarsus 1.82, total 24.50; II: 7.97, 1.40, 8.69, 9.30, 1.98, 29.34; III: 6.69, 1.29, 6.42, 7.48, 1.69, 23.57; IV: 7.23, 1.35, 7.20, 9.21, 1.69, 26.68. Palp: femur 1.61 long, 0.28 wide; patella 0.54 long, 0.34 wide; tibia 1.07 long, 0.26 wide; tarsus 1.67 long, 0.23 wide. Labium 0.67 long, 0.54 wide. Sternum 1.98 long, 1.68 wide. Femur I 1.7 times as long, tibia I 1.8 times as long and leg I 6.1 as long as carapace. Palpal femur 5.7 times longer than wide, tibia 4.1 longer than wide, tarsus not incrassate (Fig. 38). Spermathecae are a large, weakly sclerotized pouch with two large receptacles on its distal portion. Dorsal parts of bursa copulatrix have a small, sclerotized triangular area (Figs 39-41). Carapace with some sparse, long, greyish setae (Fig. 37). Carapace light brown, cephalic area, fovea, and border darker (Fig. 37). Chelicerae reddish brown. Abdomen greyish, legs light brown, both covered by short greyish setae. Palp femur and patella light brown, tibia and tarsus reddish brown (Fig. 38). Coxae and sternum light brown, labium and endites brown.

Etymology.

The specific name refers to the type locality of the species, Carinhanha, a municipality in the southwestern section of the state of Bahia, Brazil. The region possesses several cave systems with high diversity and a fragile subterranean fauna.

Remarks.

Loxosceles carinhanha  sp. n. and L. cardosoi  sp. n. males have a uniformly reddish carapace (Figs 28, 42) instead of the brown marked carapace characteristic of the groups gaucho  and rufescens  / amazonica  , and femur I has macrosetae on its prolateral median area (Figs 36, 48), which is exclusive of the two species. They occur in closer areas and are probably sister species. The inclusion of the two species in one of the groups defined by Gertsch (1967) for South American Loxosceles  is not simple question. They could fit in either gaucho  or rufescens  / amazonica  groups. Males of gaucho  group have the cymbium and tibia subequal in length ( Gertsch 1967). However, two species described more recently has slightly longer and slender tibia ( L. chapadensis  and L. niedeguidonae  ). Even though the tibia is not incrassate in these species, the cymbium is larger than the bulb, projecting forward. Considering the variation of tibia length and width in this group, we consider the cymbium size a better character to diagnose males of gaucho  group. Males of the rufescens  / amazonica  group have the cymbium considerably shorter than tibia. More important, however, is they are never much more larger than the bulb. Based in this criterion, both L. carinhanha  sp. n. and L. cardosoi  sp. n. can be included in the rufescens  / amazonica  group (Figs 32, 33, and 46, 47). Concerning females, those of the gaucho  group are readily recognizable by "the seminal receptacles attached to immovable, sclerotized, transverse plate" ( Gertsch 1967). We noted that in species of gaucho  group the receptacles are always slender and strongly sclerotized, except the apex and can be another diagnostic character. Those of the rufescens  / amazonica  group have the "seminal receptacles with a cluster of small, globular lobes at apex" ( Gertsch 1967). More recently, at least two species were known to have a single large lobe at apex, L. mahan  Planas & Ribera, 2015 from Canary Islands and L. willianilsoni  , from Brazil ( Fukushima et al. 2017). We consider that the main characters shared by females of rufescens  / amazonica  group is the spermathecae triangular shape, two free receptacles (not attached to a transverse sclerotized plate) with large basal transverse openings with or without sclerotized edges and two dark sclerotized lateral bands with distinct levels of sclerotization depending on the species (see Planas and Ribera 2015 and Fukushima et al. 2017 for spermathecae variation). Loxosceles cardosoi  sp. n. females have a transverse sclerotized plate (compatible with those species of gaucho  group) and the receptacles are short (contrary to rufescens  / amazonica  group) and broad (as in the rufescens  / amazonica  group). A single dark sclerotized band is present (another characteristic of rufescens  / amazonica  group). The bursa copulatrix is strongly sclerotized. The putative sister species, L. carinhanha  sp. n. has spermathecae weakly sclerotized lacking a transverse sclerotized plate and the receptacles are free. The bursa copulatrix is weakly sclerotized, except for a central triangular area. In favor of the inclusion of L. cardosoi  sp. n. and L. carinhanha  sp. n. in rufescens  / amazonica  group are the short cymbium in males and the broad and no sclerotized receptacles in females. Additionaly, L. carinhanha  sp. n. spermathecae have a single dark sclerotized band. There is no supporting character for the inclusion of males in the gaucho  group. In females, L. cardosoi  sp. n. has the characters transverse sclerotized plate and short receptacles, which are lacking in L. carinhanha  sp. n. Therefore, it seems more parsimonious to include the two species in the rufescens  / amazonica  group, elevating to five the number of species of this group in South America. These two species are very distinctive of the other species of the group both in the New and the Old World.

It has been proposed the origin of Loxosceles rufescens  group in the Old World with a posterior introduction of L. amazonica  during portuguese colonization of Brazil beginning in 1500 ( Duncan et al. 2010). One of the evidences for the introduction hypothesis was the lack of other related species in South America ( Duncan et al. 2010). Recently, Fukushima et al. (2017) described two species related with L. amazonica  and L. rufescens  from Brazil and argued contrary to this possibility for the short time (500 years) for speciation taking place. The discovery of two additional and very distinctive species reinforces the proposal of Fukushima et al. (2017). As the Loxosceles  diversity in South America is still largely unknown, it is necessary more efforts to collect and describe species from more remote areas of Brazil, mainly those in the northeastern and central western regions, as the areas under study here, which seems to be a hot spot for Loxosceles  diversity.

Kingdom

Animalia

Phylum

Arthropoda

Class

Arachnida

Order

Araneae

Family

Sicariidae

Genus

Loxosceles