Xenoctenus kaatinga Faustino-Magalhaes & Santos, 2024

Faustino-Magalhaes, Mayara D., Piacentini, Luis N. & Santos, Adalberto J., 2024, The desert wolf-spider genus Xenoctenus: two endemic species from the Brazilian Caatinga, and a redescription of the type-species, X. unguiculatus (Araneae: Xenoctenidae), Zootaxa 5399 (5), pp. 517-539 : 531-536

Xenoctenus kaatinga Faustino-Magalhaes & Santos sp. nov.

Figs 11 , 12 , 13C, D , 14 , 16

Type material. HOLOTYPE: BRAZIL. Piauí: Alvorada do Gurguéia, Fazenda Escola da Universidade Federal do Piauí [8°22’11.5’’S, 43°51’30.2’’W], D.B.S. Barbosa et al. coll., 30/VI/2018, 1 ♁ ( CHNUFPI 4390 ) . PARATYPES: BRAZIL. Piauí: Alvorada do Gurguéia, Fazenda Escola da Universidade Federal do Piauí [8°22’11.5’’S, 43°51’30.2’’W], D.B.S. Barbosa et al. coll., 30/VI/2018, 1 ♀ ( CHNUFPI 4391 ); Guaribas, Parque Nacional da Serra das Confusıes [9°13’12.3’’S, 43°29’26.7’’W], P.R.R. Silva et al. coll., VI/2007, 2 ♁ ( UFMG 30406 ) .

Etymology. The specific epithet is the Tupi for white forest (ka’a [forest], tinga [white]), which is also the etymology of the Brazilian semi-arid Caatinga. Tupi is one of the major language families spoken by native people in Brazil.

Diagnosis. Males can be distinguished from those of all other species of the genus by the tegular distal division (TDD) being oblong, with a straight tip ( Figs 11A–C , 12A–B , 13C ). Additionally, they differ from X. vittatus by the median apophysis being thin and cylindrical ( Figs 11B, C , 12A , 13C ). The RTA of X. kaatinga differs from that of X. vittatus by the presence of a macrosetae-like projection, and from those of X. unguiculatus by its straight tip ( Figs 11C , 12B ). Females of X. kaatinga resemble those X. unguiculagus in the epigynum being longer than wide ( Figs 6A, B , 12C, D ), but differ by the lateral lobes extension (LLE) ending at the base of the epigynum, parallel to the lateral lobes ( Fig. 12C ). Females also differ from X. vittatus and X. pampeanus by the median field lacking a longitudinal groove ( Fig. 12C ). The internal female genitalia of X. kaatinga resemble that of X. unguiculatus in the secondary spermathecae medially curved and thinner than the primary spermathecae, but differ by the secondary spermathecae being longer, posteriorly directed and medially adpressed to the primary spermathecae ( Fig. 12D ).

Description. MALE FROM FAZENDA ESCOLA DA UFPI, ALVORADA DO GURGUḖIA, PIAUÍ, BRAZIL (CNHUFPI 2450; FIG. 6 ). Carapace light brown, with dark brown lateral bands running from eyes to posterior margin of carapace ( Fig. 11D ). Opisthosoma light brown dorsally, with dark brown lateral bands, following carapace pattern, and densely covered by long setae anteriorly ( Fig. 11D ). Chelicerae light brown with median dark brown band. Labium, endites and sternum brown. Legs light brown, with dark spots ( Fig. 11D ). Pedipalps pale yellow, tibia with ventral macrosetae and entirely covered by setae ( Figs 11 C , 12B ). Cymbium covered by setae and with apical thick scopula ( Figs 11A– C , 12 A, B , 13C ). Copulatory bulb sclerotized, dark, longer than wide ( Figs 11A– C , 12 A, B ). Conductor membranous and translucent ( Figs 11 A, C , 12 A, B , 13C ). Embolus flat, with locking lobe at base and subtegular locking lobe ( Figs 11A– C , 12 A, B , 13C ). Tegular distal division (TDD) oblong, with straight tip ( Figs 11A– C , 12 A, B , 13C ). Retrolateral tegular projection apical, long, concave, following conductor ( Figs 11A– C , 12 A, B , 13C ). Median apophysis thin, cylindrical ( Figs 11 B, C , 12 A , 13C ). Total length 10.20. Carapace length 5.30, width 4.80. Eye diameters: AME 0.33, PME 0.31, ALE 0.15, PLE 0.36. Femur of leg I: 6.80. II: 6.60. III: 6.60. IV: 7.90.

FEMALE FROM FAZENDA ESCOLA DA UFPI, ALVORADA DO GURGUḖIA, PIAUÍ, BRAZIL (CNHUFPI 2448). Coloration as in male. Epigynum sclerotized, oval, longer than wide ( Fig. 12C, D ). Lateral lobes extension ending at base of epigynum ( Fig. 12C ). Median field lightly sclerotized, translucent, and without groove ( Fig. 12C ). Internal genitalia sclerotized, dark brown ( Fig. 12D ). Primary spermathecae long; secondary spermathecae shorter, thin, posteriorly directed and medially adpressed to primary spermathecae ( Figs 12D , 13D ). Total length 14.40. Carapace length 5.90, width 4.80. Eye diameters: AME 0.36, PME 0.43, ALE 0.25, PLE 0.41. Femur of leg I: 5.30. II: 5.30. III: 5.40. IV: 7.00.

Variation. In contrast to X. vittatus , males and females of X. kaatinga do not show significant variation in genitalia or in body size. However, this might be a consequence of insufficient sampling, as X. kaatinga has a narrower distribution ( Fig. 16 ) and is less represented in collections. Total body length: female, 13.8–14.4 (n=3). Male, 8.75–11.3 (n=21).

Distribution. Northeastern Brazil, at the middle portion of the Caatinga domain, in the Caatinga stricto sensu ( Fig. 16 ).

Additional material examined. BRAZIL. Bahia: Xique-Xique [10°49’24.05’’S, 42°43’30.08’’W, 408m], P.Rocha coll., 29/II/1996, 1 ♁ ( IBSP 11806 ) . Pernambuco: Buíque, Parque Nacional do Catimbau [8°36’0’’S, 37°9’0’’W], M.C. Carvalho coll., 2–4/VI/2007, 1 ♁ ( UFMG 4843 ) ; Vale do Catimbau [8°35’30.3’’S, 37°14’53.8’’W], D. Araújo & D.M. Cella coll., 6/XI/2002, 1 ♀ ( IBSP 36919 ) . Piauí: Alvorada do Gurguéia, Fazenda Escola da Universidade Federal do Piauí [8°22’11.5’’S, 43°51’30.2’’W], D.B.S. Barbosa et al. coll., 30/VI/2018, 3 ♁ 1 ♀ (CHNUFPI 2448); 10 ♁ (CHNUFPI 2450); Guaribas , Parque Nacional da Serra das Confusıes [9°13’12.3’’S, 43°29’26.7’’W], P.R.R. Silva et al. coll., VI/2007, 1 ♁ (CHNUFPI 2413); ito [9°13’10’’S, 43°29’27’’W], Giovana coll., 11–26/I/2002, 1 ♁ ( IBSP 56027 ); São Raimundo Nonato, Parque Nacional da Serra da Capivara [8°41’42.82’’S, 42°35’10.18’’W, 565 m], R. Recorder coll., 10/II–3/III/2013, 1 ♁ ( IBSP 168388 ) .

Figures

FIGURE 6. Xenoctenus unguiculatus Mello-Leit„o, 1938, female epigynum (A, C) and internal genitalia (B, D). A, B, female from Caucete, San Juan, Argentina (MACN-Ar 35624). A, ventral. B, dorsal. C, D, female from PN Sierra de las Quijadas, San Luis, Argentina (MACN-Ar 45013). C, ventral. D, dorsal. Abbreviations: CD, copulatory ducts; LL, lateral lobes; LLE, lateral lobes extension; MF, median field; S1, primary spermathecae; S2, secondary spermathecae.

FIGURE 11. Xenoctenus kaatinga Faustino-Magalhaes & Santos sp. nov., male from Alvorada do Gurguéia, Piauí, Brazil (CNHUFPI 2450).A–C, bleached palp. A, prolateral. B, ventral. C, retrolateral. D. habitus, dorsal.Abbreviations: C, conductor; E, embolus; MA, median apophysis; RTA, retrolateral tibial apophysis; RTP, retrolateral tegular projection; StLL, subtegular locking lobe. White star on tegular distal division (TDD).

FIGURE 12. Xenoctenus kaatinga Faustino-Magalhaes & Santos sp. nov., male and female from Alvorada do Gurguéia, Piauí, Brazil (CNHUFPI 2448). A–B, expanded, bleached male palp. A, prolateral. B, retrolateral. C, bleached female epigynum, ventral. D, bleached internal female genitalia, dorsal. Abbreviations: C, conductor; CD, copulatory ducts; E, embolus; ELL, embolar locked lobe; LL, lateral lobes; LLE, lateral lobes extension; MA, median apophysis; MF, median field; RTA, retrolateral tibial apophysis; RTP; retrolateral tegular projection; S1, primary spermathecae; S2, secondary spermathecae; St, subtegulum, StLL, subtegular locking lobe; T, tegulum. White star on tegular distal division (TDD).

FIGURE 13. A–B, Xenoctenus vittatus (Mello-Leit„o, 1936) comb. nov., male and female from Itacuruba, Pernambuco, Brazil (UFMG 20060). A, male palp, ventral. B, female internal genitalia, dorsal. C–D, Xenoctenus kaatinga Faustino-Magalhaes & Santos sp. nov., male and female from Alvorada do Gurguéia, Piauí, Brazil (CHNUFPI 2448). C, male palp, ventral. D, female internal genitalia, dorsal. Abbreviations: C, conductor; CD, copulatory ducts; E, embolus; MA, median apophysis; RTP, retrolateral tegular projection; StLL, subtegular locking lobe; S1, primary spermathecae; S2, secondary spermathecae. Black star on tegular distal division (TDD).

FIGURE 14. Geographic distribution records of Xenoctenus Mello-Leit„o, 1938 in South America.

FIGURE 16. Geographic distribution records of Xenoctenus kaatinga Faustino-Magalhaes & Santos sp. nov. and Xenoctenus vittatus (Mello-Leit„o, 1936) comb. nov. on northeastern Brazilian Caatinga domain. The type locality of X. vittatus is uncertain, as it is reported only as the Brazilian state of Paraiba.