Loxosceles tolantongo, Navarro-Rodríguez & Valdez-Mondragón, 2020

Navarro-Rodríguez, Claudia Isabel & Valdez-Mondragón, Alejandro, 2020, Description of a new species of Loxosceles Heineken & Lowe (Araneae, Sicariidae) recluse spiders from Hidalgo, Mexico, under integrative taxonomy: morphological and DNA barcoding data (CO 1 + ITS 2), European Journal of Taxonomy 704, pp. 1-30 : 7-17

Loxosceles tolantongo sp. nov.

urn:lsid:zoobank.org:act:C49E731B-3592-4AF2-8C3B-7DA78E4E2D47

Figs 1–9 , 16–33 , 36–39

Differential diagnosis

Loxosceles tolantongo sp. nov. morphologically resembles L. jaca Gertsch & Ennik, 1983 , also from Hidalgo. However, in lateral view, the palp tibia of the male L. tolantongo sp. nov. is slightly longer than in L. jaca and the curvature of the basal-ventral part of the tibia is less pronounced than in L. jaca ( Figs 20, 22 , 30, 33 ), where it is prominent and totally curved ( Figs 34–35 , 44, 46 ). In dorsal view, the palp tibia of L. tolantongo sp. nov. is thinner and longer ( Fig. 21 ), whereas in L. jaca it is wider and shorter ( Fig. 45 ). In the new species, in lateral view, the embolus is slightly wider basally than that of L. jaca ( Figs 20, 22 vs Figs 44, 46 ). In lateral and dorsal views, the tip of the embolus in L. tolantongo sp. nov. is slightly curved ( Figs 20, 22, 24 ), whereas in L. jaca it is sigmoid ( Figs 44, 46, 48 ). The seminal receptacles of the females of both species are similarly S-shaped ( Figs 36–39, 40–43 ). However, the shape of the base of the receptacles is different: in L. tolantongo sp. nov. it is oval-shaped ( Figs 28 , 36–39 ), whereas in L. jaca it is square-shaped ( Figs 40–43 ). Also, the base of seminal receptacles is more sclerotized in L. tolantongo sp. nov. than in L. jaca ( Figs 28 , 36–39, 40–43 ).

Etymology

The species name is a noun in apposition and refers to the type locality of the new species: the Tourist Center Grutas de Tolantongo, located in the Mezquital Valley, Hidalgo, Mexico.

Material examined

Holotype

MEXICO – Hidalgo • ♂; Municipality of Cardonal, Tourist Center Grutas de Tolantongo ; 20.6503° N, 99.0047° W; 1315 m a.s.l.; 17 Mar. 2017; A. Valdez, E. Briones, J. Valerdi, A. Juárez and M. Sánchez leg.; night collecting; CNAN-T01317 .

Paratypes

MEXICO – Hidalgo • 1 ♂; same collection data as for holotype; CNAN-T01319 • 1 ♂; same collection data as for holotype; 22 May 2018; A. Valdez, J. Valerdi, A. Cabrera, P. Solís and I. Navarro leg.; diurnal collecting; CNAN-T01320 • 2 ♀♀; same collection data as for preceding; CNAN-T01321 , CNAN-T01324 • 1 ♂; Municipality of Cardonal, Tourist Center Grutas de Tolantongo, 500 m west of entrance No. 5; 20.6446° N, 98.9973° W; 1481 m a.s.l.; 22 May 2018; A. Valdez, J. Valerdi, A. Cabrera, P. Solís and I. Navarro leg.; diurnal collecting; CNAN-T01318 • 2 ♀♀; same collection data as for preceding; CNAN-T01322 , CNAN-T01323 .

Other material

MEXICO – Hidalgo • 1 ♂, 5 immatures; Municipality of Cardonal, Tourist Center Grutas de Tolantongo, 500 m west of entrance No. 5; 20.6446° N, 98.9973° W; 1481 m a.s.l.; 22 May 2018; A. Valdez, J. Valerdi, A. Cabrera, P. Solís and I. Navarro leg.; diurnal collecting; LATLAX Ara-0488 • 1 ♂, 1 immature; same collection data as for holotype; 23 May 2018; LATLAX Ara-0490 • 2 immatures; same collection data as for holotype; 22 May 2018; A. Valdez, J. Valerdi, A. Cabrera, P. Solís and I. Navarro leg.; diurnal collecting; LATLAX Ara-0489 • 1 ♂, 2 immatures; same collection data as for holotype; LATLAX Ara- 0137 • 6 ♀♀, 4 immatures; Municipality of Cardonal, Tourist Center Grutas de Tolantongo, ʻEl Paraisoʼ trail ; 20.6502° N, 99.0002° W; 1312 m a.s.l.; 24 Jan. 2019; A. Valdez, P. Solís, M. Cortez, J. Sánchez and D. Montiel leg.; LATLAX Ara-0527 , Ara-0528 .

Description

Male (holotype CNAN-T01317)

Specimen collected manually, preserved and observed in 80% ethanol.

MEASUREMENTS. Total length 5.60. Carapace: 2.60 long, 2.30 wide. Clypeus length 0.25. Diameter of AME 0.20, PME 0.17, PLE 0.13; AME-PME 0.11. Labium: length 0.44, width 0.50. Sternum: length 1.40, width 1.25. Leg lengths: I (total 14.80): femur 4.0/ patella 0.9/ tibia 4.6/ metatarsus 4.1/ tarsus 1.2; II (15.20): 4.4/ 0.7/ 4.6 /4.4 / 1.1; III (12): 3.6/ 0.6/ 3.2/ 3.6 /1; IV (14.60): 4 /0.7 / 3.7/ 4.9/ 1.3. Leg formula: 2-1-4-3.

PROSOMA. Carapace reddish, longer than wide, pyriform, dorsally with slightly dark brown ʻviolinʼ pattern ( Figs 1–5 , 16 , 26 ), which is darker brown than rest of body ( Figs 1–5 , 16 , 26 ). Carapace without lateral spots like other species. Six eyes in three groups, clypeus reddish brown ( Figs 1–5 , 16 , 26 ). Sternum pale reddish, longer than wide ( Fig. 17 ). Labium reddish brown, wider than long, fused to the sternum ( Fig.17 ). Endites pale brown basally, reddish brown distally and white apically. Endites longer than wide, rounded basally ( Fig.17 ).

LEGS. Coxae, trochanters, femora and patella reddish brown, paler on femora III and IV ( Figs 1–5 , 16–17 ), and the rest of the leg browner ( Figs 1–5 , 16 ).

CHELICERAE. Fused basally, reddish brown, stridulatory lines laterally. Fangs reddish brown, with thin setae around them ( Fig. 17 ).

OPISTHOSOMA. Dark gray, paler posteriorly ( Fig 1–5 , 16 ), oval, longer than wide, and high ( Figs 1–5 , 16–17 ). Region of gonopore pale gray, with small setae. Colulus reddish brown, conical ( Fig. 17 ). Spinnerets reddish brown, cylindrical; anterior lateral spinnerets longest, posterior median spinnerets smallest, with long setae. Tracheae opening near posterior margin of opisthosoma.

PALPS. Trochanters and femora pale reddish, paler ventrally in femora; patellae, tibiae reddish brown, longer than wide, wider in distal half than basal half ( Figs 20, 22 , 30–33 ). Tarsus oval, reddish brown, bulb spherical, embolus short, thick at base, narrowed to fine point ( Figs 20–25 ).

Female (paratype CNAN-T01264)

Specimen collected manually, preserved and observed in 80% ethanol.

MEASUREMENTS. Total length 6.64. Carapace: 2.71 long, 2.56 wide. Clypeus length 0.34. Diameter of AME 2, PME 1.8, PLE 1.8; AME-PME 0.2. Labium: length 0.42, width 0.57. Sternum: length 1.56, width 1.36. Leg lengths: I (total 12.42): femur 3.6/ patella 0.88 / tibia 3.36 / metatarsus 3.40 / tarsus 1.18; II (16.65): 3.8/ 1.0/ 3.8 /3.45 / 4.6; III (11.72): 3.60 / 0.96 / 3.04 / 3.06 /1.06; IV (13.23): 3.44 / 0.96 / 3.52 /4.0 / 1.31. Leg formula: 2-4-1-3.

Differs from male as follows:

PROSOMA. Carapace brown and pale brown, with less defined dark brown ʻviolinʼ pattern ( Figs 6–9 , 18 , 27 ). Larger carapace. Sternum paler brown ( Fig. 19 ). Labium more reddish brown. Endites more reddish brown.

LEGS. Coxae, trochanters, femora, patella and tibiae brown ( Figs 6–9 , 18–19 ). Metatarsi and tarsi dark brown ( Figs 6–9 , 18–19 ).

CHELICERAE. Darker reddish brown.

OPISTHOSOMA. Brown and pale brown ( Figs 6–9 , 18–19 ). Spinnerets paler brown.

PALPS. Trochanters, femora and patellae pale brown, tibiae and tarsi reddish brown. Tibiae cylindrical, tarsi conical ( Figs 18–19 ).

GENITAL AREA. Seminal receptacles asymmetric, S-shaped ( Fig. 28 ). Base of seminal receptacles oval and wide, sclerotized ( Fig. 28 ). See variation section for more details ( Figs 36–39 ).

Variation

Males

Males collected from the Tourist Center Grutas de Tolantongo and from 500 m west of entrance No. 5 are pale brown, with legs the same color as carapace; in some cases the legs are darker than the body. The male holotype is darker brown that all other specimens. The male collected from ʻEl Paraisoʼ trail is dark reddish brown, with legs the same color as body. Tourist Center Grutas de Tolantongo, Municipality of Cardonal (N = 5): Tibia I 4.1–5.4 (x = 5); carapace length (CL) 2.2–2.6 (x = 2.5), carapace width (CW) 2.1–2.3 (x = 2). 500 m west of entrance No. 5, Municipality of Cardonal (N = 2): Tibia I 4.1–4.3 (x = 4), CL 2.2–2.4 (x = 2), CW 2.0–2.2 (x = 2). ʻEl Paraisoʼ trail, Municipality of Cardonal (N = 1): Tibia I 5.2, CL 2.7, CW 2.4.

The male palps present a little variation. In the case of the holotype the palp has more marked coloration and the embolus is wider at the base ( Figs 20–25 , 30–33 ).

Females

The female collected from the Tourist Center Grutas de Tolantongo is pale brown on carapace and legs. Females from 500 m west of entrance No. 5 are dark brown on carapace and legs. Females from ʻEl Paraisoʼ trail are dark brown on carapace, with light brown legs. Tourist Center Grutas de Tolantongo, Municipality of Cardonal (N = 2): Tibia I 3.3–3.3 (x = 3), CL 2.2–2.7 (x = 3), CW 2.0–2.5 (x = 2). 500 m west of entrance No. 5, Municipality of Cardonal (N = 2): Tibia I missing–3.2, CL 2.6–2.6 (x = 3), CW 2.2–2.3 (x = 2). ʻEl Paraisoʼ trail, Municipality of Cardonal (N = 6): Tibia I 3.1–3.9 (x = 3), CL 2.4–2.7 (x = 3), CW 2.2–2.4 (x = 2).

The seminal receptacles of females are S-shaped, asymmetrical and broadly variable in shape, even in specimens from the same locality ( Figs 36–39 ). The apical lobes are rounded in some specimens, oval in

others, or even with a sharp tip ( Figs 28 , 36–39 ). The base of the seminal receptacles is variable, in some specimens it is wider, more rounded and more sclerotized than in others ( Figs 28 , 36–39 ).

Natural history

The specimens of L. tolantongo sp. nov. were collected in a xerophytic forest, the native vegetation type around the Touristic Center Grutas de Tolantongo ( Figs 10–15 ). The microhabitat where the specimens were collected was under big rocks, and from inside rotten and dry agave plants ( Figs 12–15 ). Some specimens were collected close to each other.

Distribution

MEXICO: Hidalgo ( Figs 50–51 ).

Molecular analyses and species delimitation

The analyzed matrices include 49 individuals of ten species of Loxosceles , 38 individuals for the CO1 data set and 42 individuals for ITS2 ( Table 1 , Figs 52–56 ). Specimens used in this study, GenBank accession numbers and localities of the specimens are listed in Table 1 . The average genetic p- distance among analyzed species was 15.9% for CO1 and 8.4% for ITS2 ( Figs 52–53 ). Corrected p- distances from the CO1 and ITS2 data recovered nine species of Loxosceles , both with high bootstrap support values ( Figs 52–53 ). Based on the genetic analyses, L. tolantongo sp. nov. is closely related to L. jaca + L. tenango with CO1 ( Fig. 52 ), and with L. jaca with ITS2 ( Fig. 53 ); with an average p -distance between L. tenango and L. tolantongo sp. nov. of 9.6%, and between L. jaca and L. tolantongo sp. nov. of 10.5% for CO1 and 1.8% for ITS2 ( Tables 3–4). Molecular analyses with CO1 and the concatenated matrix (CO1 + ITS2) ( Figs 54 , 56 ) indicate that four different species delimitation methods, including the morphology, were congruent to delimit L. tolantongo sp. nov. as a valid and different species, and recovered a total of nine species. However, using the ABGD species delimitation method under recursive partitions (RP), 14, 11 and 10 species were recovered ( Fig. 54 ). The molecular analyses are consistent with the morphology; the nine species of Loxosceles used in this study were previously described only with morphological characters, except for L. tenochtitlan which was described with different lines of evidence (morphological and molecular) by Valdez-Mondragón et al. (2019). Molecular analyses with ITS2 indicate that of the four different molecular species delimitation methods, only NJ and GMYC (Yule) were consistent with the morphology for delimitation of L. tolantongo sp. nov. ( Figs 53 , 55 ). ABGD and bPTP species delimitation methods do not recover L. totaltongo as a different species, but they recover other species, such as L. zapoteca Gertsch, 1958 , L. colima Gertsch, 1958 (except with initial partitions (IP) (ABGD)) and L. malintzi ( Fig. 55 ). The haplotype network analysis with CO1 data is concordant with the results of the different species delimitation analyses ( Fig. 57 ). There were>10 mutations between haplotypes under CO1 for all the species ( Fig. 57 ). Regarding L. tolantongo sp. nov. and L. jaca + L. tenango , the haplotype network was concordant with the species delimitation, and showed a total of 39 and 36 mutations respectively between haplotypes under CO1 ( Fig. 57 ).

Figures

Figs 1–5. Live male holotype (CNAN-T01317) of Loxosceles tolantongo sp. nov. from the type locality: Tourist Center Grutas de Tolantongo, Municipality of Cardonal, Hidalgo, Mexico. Photos 1–4 by Alejandro Valdez-Mondragón (2019); photo 5 by Claudia Isabel Navarro-Rodríguez (2019).

Figs 6–9. Live female paratype (CNAN-T01321) of Loxosceles tolantongo sp. nov. from the type locality: Tourist Center Grutas de Tolantongo Municipality of Cardonal, Hidalgo, Mexico. Photos 6–7 by Alejandro Valdez-Mondragón (2019); photos 8–9 by Claudia Isabel Navarro-Rodríguez (2019).

Figs 16–19. Loxosceles tolantongo sp. nov. 16–17. Habitus of ♂ holotype (CNAN-T01317), dorsal and ventral views, respectively. 18–19. Habitus of ♀ paratype (CNAN-T01321), dorsal and ventral views, respectively. Scale bars = 2 mm.

Figs 20–25. Loxosceles tolantongo sp. nov., ♂ holotype (CNAN-T01317). 20–22. Left palp, prolateral, dorsal and retrolateral views, respectively. 23–25. Detail of the bulb and embolus, retrolateral, dorsal and apical views, respectively. Scale bars: 20–22 = 0.5 mm; 23–25 = 0.2 mm.

Figs 26–29. Loxosceles tolantongo sp. nov. 26–27. Caparace of ♂ holotype (CNAN-T01317) and ♀ paratype (CNAN-T01321), respectively. 28–29. ♀ paratype (CNAN-T01321). 28. Seminal receptacles. 29. Genital area, ventral view. Scale bars: 26–27 = 1 mm; 28 = 0.2 mm; 29 = 0.5 mm.

Figs 30–35. Variation of the male palps, left palps, prolateral views. 30–33. Loxosceles tolantongo sp. nov. 30–32. Tourist Center Grutas de Tolantongo, Municipality of Cardonal, Hidalgo (type locality). 33. 500 m west of the entrance No. 5 to the Tourist Center Grutas de Tolantongo, Municipality of Cardonal, Hidalgo. 34–35. Loxosceles jaca Gertsch & Ennik, 1983. 2.5 km north of Jacala de Ledezma, Municipality of Jacala de Ledezma, Hidalgo. Scale bars = 0.5 mm.

Figs 36–43. Variation of the seminal receptacles of females, dorsal view. 36–39. Loxosceles tolantongo sp. nov. 36, 39. Tourist Center Grutas de Tolantongo, Municipality of Cardonal. 37–38. 500 m west of the entrance No. 5 to the Tourist Center Grutas de Tolantongo, Municipality of Cardonal. 40–43. Loxosceles jaca Gertsch & Ennik, 1983. 2.5 km north of Jacala de Ledezma, Municipality of Jacala de Ledezma, Hidalgo. Scale bars = 0.2 mm.

Figs 44–49. Loxosceles jaca Gertsch & Ennik, 1983. 44–46. Left palp, prolateral, dorsal and retrolateral views respectively. 47–49. Detail of the bulb and the embolus: retrolateral, dorsal and apical views, respectively. Scale bars: 44–46 = 0.5 mm; 47–49 = 0.2 mm.

Figs 10–15. Habitat and microhabitat of Loxosceles tolantongo sp. nov. 10–11. Xerophytic forest from the type locality: Tourist Center Grutas de Tolantongo, Municipality of Cardonal, Hidalgo, Mexico. 12–15. Microhabitat situated 500 m west of entrance No. 5 to the Tourist Center Grutas de Tolantongo, Municipality of Cardonal, Hidalgo, Mexico (arrows indicate the microhabitat where the specimens can be found: under big rocks and inside of rotten and dry agave plants). Photos 10, 12–14 by Claudia Isabel Navarro-Rodríguez (2018); photos 11, 15 by Alejandro Valdez-Mondragón (2018).

Figs. 50–51. Distribution records of Loxosceles tolantongo sp. nov. from Hidalgo. 50. Known records of Loxosceles tolantongo sp. nov. from the Tourist Center Grutas de Tolantongo, Municipality of Cardonal, Hidalgo, including the type locality. 51. Distribution records of the four species of Loxosceles from Hidalgo, Mexico. Abbreviations: HGO = Hidalgo; MEX = Estado de Mexico; PUE = Puebla; SLP = San Luis Potosí; VER = Veracruz.

Fig. 52. Neighbor joining tree constructed from CO1 data of nine species of Loxosceles Heineken & Lowe, 1832 from Mexico. Colors of branches indicate different species. Numbers on nodes are bootstrap support values. Red circle at node represents Loxosceles tolantongo sp. nov.

Fig. 53. Neighbor joining tree of ITS2 data of nine species of Loxosceles Heineken & Lowe, 1832 from Mexico. Colors of branches indicate different species. Numbers at nodes represent bootstrap support values. Red circle at node represent Loxosceles tolantongo sp. nov.

Fig. 54. Maximum likelihood tree inferred from CO1 gene of species of Loxosceles Heineken & Lowe, 1832 from Mexico. Colors of branches and bars indicate different species. Numbers above bars represent the delimitation methods: 1 = morphology (M); 2 = neighbor joining (NJ); 3 = ABGD with initial partitions (IP); 4–6 = ABGD with recursive partitions (RP); 7 = GMYC yule analysis; 8 = GMYC coalescent analysis; 9 = bPTP with ML; 10 = bPTP with IB. Numbers below bars represent species recovered for each delimitation method. Red numbers on branches correspond to Bayesian posterior probabilities, black numbers are bootstrap support values from the ML analysis.

Fig. 55. Maximum likelihood tree inferred from ITS2 gene of species of Loxosceles Heineken & Lowe, 1832 from Mexico. Colors of branches and bars indicate different species. Numbers above bars represent the delimitation methods: 1 = morphology (M); 2 = neighbor joining (NJ); 3–4 = ABGD with initial partitions (IP); 5–7 = ABGD with recursive partitions (RP); 8 = GMYC yule analysis; 9 = GMYC coalescent analysis; 10 = bPTP with ML; 11 = bPTP with IB. Numbers below bars represent species recovered for each delimitation method. Red numbers on branches correspond to Bayesian posterior probabilities, black numbers are bootstrap support values from the ML analysis.

Fig. 56. Maximum likelihood tree inferred from the concatenated matrix (CO1 + ITS2) of species of Loxosceles Heineken & Lowe, 1832 from Mexico. Colors of branches and bars indicate different species. Numbers above bars represent the delimitation methods: 1 = morphology (M); 2 = neighbor joining (NJ); 3 = ABGD with initial partitions (IP); 4–5 = ABGD with recursive partitions (RP); 6 = GMYC yule analysis; 7 = GMYC coalescent analysis; 8 bPTP with ML; 9 = bPTP with IB. Numbers below bars represent species recovered for each delimitation method. Red numbers correspond to Bayesian posterior probabilities, black numbers are bootstrap support values from the ML analysis.

Fig. 57. Haplotype network from the CO1 data obtained with TCS using PopArt. Each circle represents the haplotypes found in nine species of Loxosceles Heineken & Lowe, 1832 from Mexico. Numbers on branches indicate the number of mutations between haplotypes.