Loxosceles willianilsoni, Fukushima, Caroline Sayuri, Andrade, Rute Maria Goncalves de & Bertani, Rogerio, 2017

Fukushima, Caroline Sayuri, Andrade, Rute Maria Goncalves de & Bertani, Rogerio, 2017, Two new Brazilian species of Loxosceles Heinecken & Lowe, 1832 with remarks on amazonica and rufescens groups (Araneae, Sicariidae), ZooKeys 667, pp. 67-94 : 76-79

Loxosceles willianilsoni sp. n. Figs 52-55, 56-57, 58-61, 62-65, 66-69, 78-79

Material examined

(Table 3). Male holotype (MNRJ 6953) and female paratype (MNRJ 6954), BRAZIL: Rio Grande do Norte, Martins, Casa de Pedra cave (06°05'S, 37°55'W), C. S. Fukushima col., 2014.

Other material examined

(Table 3). Casa de Pedra cave (06°05'S, 37°55'W), 319 m a.s.l., 1 female, A. P. L. Giupponi col., 2014, ref. A100 (MNRJ 6955); 1 female, N. M. Gonçalves col., 2014, ref. N60 (MNRJ 6956); 1 female, N. M. Gonçalves col., 2014, ref. N63 (MNRJ 6957); 1 female, C. S. Fukushima col., 2014, ref. C92 (MNRJ 6958); 1 female, C. S. Fukushima col., 2014, ref. C481 (MNRJ 6959); 1 male, N. M. Gonçalves col., 2014, ref. N59 (MNRJ 6960); 1 male, A. P. L Giupponi col., 2014, ref. A107 (MNRJ 6961); 1 male, C. S. Fukushima col., ref. C76 (MNRJ 6962); 1 male, K. C. T. Riciluca col., 2014, ref. K33 (MNRJ 6963); 1 male, A. P. L. Giupponi col., 2014, ref. A102 (MNRJ 6964); 1 male, C. S. Fukushima col., 2014, ref. C64 (MNRJ 6965); 1 male, C. S. Fukushima col., 2014, ref. C72 (MNRJ 6966), 1 female, C. S. Fukushima col, 2014, ref. C479 (MNRJ 6951).

Diagnosis.

Males of Loxosceles willianilsoni sp. n. resemble those of L. amazonica , L. rufescens , L. bentejui , L. foutadjalloni , L. guayota , L. hupalupa , L. lacta , L. mahan , L. tazarte , L. tibicena , and L. muriciensis sp. n. by incrassated palpal tibia, longer than cymbium (Fig. 54). They differ from those of L. hupalupa , L. mahan and L. tazarte by having shorter embolus (Fig. 54), and entire pars cephalica as well as carapace border dark brown (Fig. 52), best seen in live specimens. From those of L. amazonica , L. rufescens , L. bentejui , L. foutadjalloni , L. guayota , L. lacta , L. tibicena , and L. muriciensis sp. n. they can be distinguished by having straight embolus with a strong curvature on its apex (Fig. 53). Additionally, males of L. willianilsoni sp. n. differ from those of all these species except L. foutadjalloni , L. guayota , and L. muriciensis sp. n. by having leg I at least eight times as long as carapace (Table 1). Females of L. willianilsoni sp. n. resemble females of L. amazonica , L. rufescens , L. bentejui , L. foutadjalloni , L. hupalupa , L. lacta , L. mahan , L. tazarte , L. tibicena , and L. muriciensis sp. n. by having spermathecae with large seminal receptacles and dark sclerotized lateral bands (Fig. 57). Females of L. willianilsoni sp. n. can be distinguished from all these species by the combination of the following characters: spermathecae with dark sclerotized lateral bands almost reaching their apex, which has no lobes and no constriction forming a neck (Figs 57-61), leg I at least 6.5 times as long as carapace (Table 2). Additionally, L. willianilsoni sp. n. males and females can be distinguished from L. mahan , L. tazarte , L. bentejui , L. guayota , L. tibicena and L. hupalupa by lacking a conspicuous dark V-mark posteriorly on pars cephalica.

Description.

Male holotype (MNRJ 6953). Total length 7.39. Carapace 3.16 long, 2.74 wide. Eye sizes and interdistances: ALE 0.15, PME 0.21, PLE 0.18, PME-PLE 0.02, PME-ALE 0.15; clypeus 0.26. Leg formula II, I, IV, III. Legs length: leg I: femur 7.47, patella 0.98, tibia 8.37, metatarsus 8.85, tarsus 1.77, total 27.44; II: 8.29, 1.11, 9.88, 10.95, 1.85, 32.08; III: 6.40, 1.09, 6.23, 7.64, 1.30, 22.66; IV: 7.12, 1.05, 7.08, 8.38, 1.52, 26.15. Palp: femur 1.46 long, 0.31 wide; patella 0.49 long, 0.33 wide; tibia 0.88 long, 0.48 wide; cymbium 0.43 long, 0.42 wide. Labium 0.71 long, 0.38 wide. Sternum 1.78 long, 1.50 wide. Femur I 2.4 times as long, tibia I 2.7 times as long and leg I 8.7 as long as carapace. Palpal femur four times longer than wide, tibia 1.8 times longer than wide, cymbium oval (Fig. 54). Bulb suboval and approximately same size as cymbium. Embolus straight, with a strong curvature on apex, approximately 1.3 times longer than bulb length in retrolateral view, without carina (Fig. 53). Cephalic region of carapace covered by many long setae (Fig. 52). Entire pars cephalica as well as carapace border dark brown (Fig. 52). Legs and palps light brown, covered by short greyish setae on the femora and patellae (Fig. 64). Endites, coxae and sternum light brown. Labium dark brown.

Female paratype (MNRJ 6954): As in male, except: Total length 8.72. Carapace 2.99 long, 2.39 wide. Eye sizes and interdistances: ALE 0.14, PME 0.17, PLE 0.16, PME-PLE 0.02, PME-ALE 0.19; clypeus 0.35. Leg formula II, I, IV, III. Legs length: leg I: femur 5.25, patella 1.17, tibia 5.93, metatarsus 5.88, tarsus 1.24, total 19.47; II: 5.96, 1.14, 6.40, 6.32, 1.50, 21.32; III: 4.76, 1.00, 4.22, 4.80, 1.19, 15.97; IV: 5.32, 1.15, 4.89, 5.96, 1.40, 18.72. Palp: femur 0.98 long, 0.21 wide; patella 0.28 long, 0.25 wide; tibia 0.70 long, 0.20 wide; tarsus 1.06 long, 0.16 wide. Labium 0.53 long, 0.44 wide. Sternum 1.63 long, 1.38 wide. Femur I 1.8 times as long, tibia I 2.0 times as long and leg I 6.5 as long as carapace. Palpal femur 4.7 times longer than wide, tibia 3.5 longer than wide, tarsus not incrassate. Spermathecae with enlarged seminal receptacles; without transversal plate; and presence of dark sclerotized lateral bands almost reaching the apex (Fig. 57). Palps pale brown, except by darker tibiae and metatarsi. Endites pale brown.

Etymology.

This species is named after the biology student Willianilson Pessoa, in honor of his friendship and support during expeditions in Rio Grande do Norte. This name is masculine in gender.

Natural history.

Specimens were found inside Casa de Pedra cave walking on walls, in webs inside wall cracks or under loose stones on the cave ground. This calcarian cave is very large regarding regional patterns and has turistic use ( Ferreira et al. 2010). Apparently, specimens of L. willianilsoni sp. n. are found only inside the cave.