Brachypelma emilia, (WHITE, 1856)

Mendoza, Jorge & Francke, Oscar, 2020, Systematic revision of Mexican threatened tarantulas Brachypelma (Araneae: Theraphosidae: Theraphosinae), with a description of a new genus, and implications on the conservation, Zoological Journal of the Linnean Society 188, pp. 82-147 : 112-116

BRACHYPELMA EMILIA ( WHITE, 1856)

( FIGS 2, 23– 26, 36E–H, 38)

Mygale emilia White, 1856: 185 , pl. 43 (D male).

Brachypelma emilia ( Simon 1891: 338) , D male and female; Smith (1986: 49, fig. 27h), Tmf from Eurypelma = Avicularia ; Smith (1987: 49, plate 2, fig. 27h), male; Hancock & Hancock (1989: 46, fig. 41), female; Schmidt (1992: 10), Tmf from Euathlus per Raven; Schmidt (1993: 82, fig. 188), female; Smith (1994: 166, figs 901–915), male and female; Pérez-Miles et al. (1996: 46, figs 9–10), male and female; Tesmoingt et al. (1997a: 9, plate 2, fig. 6), female; Schmidt (1997: 19, figs 191, 193), male and female; Locht et al. (1999: 196, fig. 7), female; Peters (2000: 68, fig. 222), female; Bertani (2001: 338, figs 153–156), male and female; Peters (2003: 117, figs 473–474, 477, 480, 483), male and female; Schmidt I2003: 152, figs 274–277), male and female; Gabriel & Longhorn (2015: 100, fig. 13), female.

Material examined

Neotype of Brachypelma emilia : MEXICO: Durango: ♂, Ciudad , leg Mr. Forrer (BMNH- 1898-12-24 -32). 1 ♂ (labelled as paratype), Ciudad, leg. Forrer ( OUNMH Jar 106).

Note: Both specimens mentioned as neotype and paratype were designated by Smith (1994: 166).

Other material: MEXICO: Nayarit: 1 ♂ 4 ♀, Mpio. Compostela , 9.xii.2012, E. Goyer, E. Hijmensen, D. Ortiz (CNAN-Ar003599, CNAN-Ar007153, CNAN-Ar007173,CNAN-Ar007178,CNAN-Ar007875); 1 ♂, Mpio. Estación Ruíz, 1.xii.1989, A. Cadena (CNAN-Ar003436); 4 ♂, Mpio. Estación Ruíz, 5.xii.2014, J. Mendoza, G. Contreras (CNAN-Ar007146, CNAN-Ar007894,CNAN-Ar007895,CNAN-Ar007899) ; Sinaloa: 1 ♂, Mpio. Mazatlán , vii.1959, without more data (CNAN-Ar003427); 1 ♂ 1 ♀, Mpio. Mazatlán, 3.xii.2014, J. Mendoza, G. Contreras (CNAN-Ar007898, CNAN-Ar010602); 1 ♂, Mpio. Mazatlán, without more data, Collection E. Simon ( MP Ar4871A); 1 ♂, Mpio . Sinaloa de Leyva , 30.i.1965, without more data (CNAN-Ar003590) ; Sonora: 1 ♂, Mpio. Altar, 9.i.1970, W. Lopez Forment (CNAN-Ar003578) ; Jalisco: 1 ♀, Norte del Río Santiago, Godman, Salvin , without more data (BMNH- 1962-2-28-1); 1 ♂, donation received from private collection of J. Mendoza (CNAN-Ar003631) .

Diagnosis

Brachypelma emilia can be distinguished from all other known Brachypelma species by the coloration of the carapace and legs, with carapace orange except in the caput, which is black in colour ( Fig. 26A–C). The legs have black femora and patellae, orange tibiae and metatarsi I– III are black and IV is orange ( Fig. 36E– H). It also differs in the shape of genitalia in both sexes with palpal bulb slightly curved to dorsal having a small and narrow spoon-shape ( Fig. 24C–D). The prolateral superior keel is slightly developed, thin and directed retrolaterally ( Fig. 24A, C). The prolateral inferior keel is absent, the apical keel normally developed, wide but not shorter than prolateral superior keel ( Fig. 24B). It also differs by the spermatheca ventral face smooth, with a single receptacle strongly sclerotized slightly notched in the middle, spermathecal baseplate oblanceolate ( Fig. 25E, F).

Brachypelma emilia is identified by possesing the following character combination: male palpal bulb with narrow spoon-shape embolus curving slightly to dorsal through its length, prolateral superior keel slightly developed; apical keel normally developed, wide but not shorter than the prolateral superior keel tip. Embolus tip directed to retrolateral. Embolus similar in length than tegulum ( Fig. 24A–D). Spermatheca fused with single semitrapezoidal receptacle. Spermathecal baseplate divided, oblanceolate; one and half wider than its height ( Fig. 25E, F). Carapace of both sexes carapace orange with black triangle in the ocular area ( Fig. 26A–C).

Redescription

Male (CNAN-Ar003599) ( Figs 23, 24, 26A): Body length 40.16 (not including chelicerae and spinnerets), carapace 20.23 length, 18.85 width. Caput not markedly elevated; fovea procurved, 3.80 wide ( Fig. 23A). Eyes: anterior eye row procurved, posterior eye row recurved. Eye sizes and interocular distances: AME 0.43; ALE 0.60; PME 0.33; PLE 0.37; AME–AME 0.70; AME–ALE 0.20; PME–PME 1.23; PME–PLE 0.13; ALE–PLE 0.37. Ocular tubercle width 2.47, length 2.27; clypeus 0.23 ( Fig. 23D). Labium length 2.60, width 3.40; with 109 cuspules. Maxilla inner corner with approximately 205 (left) and 179 (right) cuspules. Cheliceral promargin with ten (left) and nine (right) teeth (proximal to distal: first–third large, fourth small, fifth–seventh medium, eighth–tenth large; first–third large, fourth small, fifth–seventh medium, eighth–ninth large). Sternum length 10.10, width 9.38. Sigilla oval, fourth pair hardly visible, posterior pair one and half its length from the margin ( Fig. 23B). Leg formula: IV, I, II, III. Length of legs and palpal segments (femur, patella, tibia, metatarsus, tarsus, total): I: 17.25, 9.39, 11.67, 12.22, 9.28, 59.81; II: 15.93, 9.20, 10.96, 11.89, 8.21, 56.19; III: 14.35, 8.11, 10.00, 12.08, 8.15, 52.69; IV: 16.86, 8.63, 12.81, 16.13, 9.92, 64.35. Palp: 11.83, 7.23, 9.61, -, 4.14, 32.81. Spinnerets: PMS, 2.20 long, 1.00 apart; PLS, 3.10 basal, 2.20 middle, 3.20 distal. Tarsi I – IV entirely scopulated. Metatarsus I entirely scopulated, II scopulated 75%, III scopulated 50% distally, IV scopulated 30% distally. Tibia I with two tibial apophyses normally developed, which originate from a common base. Prolateral apophysis with inner spine third its length; retrolateral apophysis wider in basal half, apex almost straight ( Fig. 23F, G). Metatarsus I curved ( Fig. 23E). Stridulatory setae: with claviform stridulating setae on palp trochanter retrolateral face; leg I trochanter and femur prolateral face. Chaetotaxy (left side): femora I 1p; II 1 p; palp 1p; patellae none; tibiae I 1p, 2v; II 2 p, 3v; III 2 p, 5v, 1r; IV 1 p, 4v, 1p; palp 2p, 1v; metatarsi I 1v; II 2 v; III 3 p, 7v, 1r; IV 1 p, 18v, 1r. Palp: embolus slightly curved to dorsal having a small and narrow spoon-shape, prolateral superior keel slightly developed, thin and directed retrolaterally; prolateral inferior keel absent; apical keel normally developed, wide but not shorter than prolateral superior keel. Opening of the embolus is on the prolateral side, just behind the opening is located a concavity which delimits the apical keel boundary from the remaining part of the embolus. Embolus apex slightly curved to retrolateral ( Fig. 24A–D). Urticating setae: types I and III arranged in one dorsoposterior patch, black in colour. Type III are located in an oval dorsomedial area extended to posterior. Type I surround the type III area, with intermediates between type III and I in transition areas ( Fig. 23C) .

Female (CNAN-Ar010602) ( Fig. 25A–E): Body length 61.31 (not including chelicerae and spinnerets), carapace 26.34 length, 24.33 width. Caput not markedly elevated; fovea straight, 6.40 wide ( Fig. 25A). Eyes: anterior eye row procurved, posterior eye row recurved. Eye sizes and interocular distances: AME 0.65; ALE 0.70; PME 0.50; PLE 0.70; AME–AME 0.63; AME–ALE 0.33; PME–PME 1.57; PME–PLE 0.07; ALE–PLE 0.40. Ocular tubercle width 3.25, length 2.83; clypeus 0.27 ( Fig. 25D). Labium length 3.05, width 3.85; with 94 cuspules. Maxilla inner corner with approximately 187 (left)–208 (right) cuspules. Cheliceral promargin with nine (left)–nine (right) teeth. Sternum length 11.60, width 10.90. Sigilla oval, fourth pair hardly visible; posterior pair twice its length from the margin ( Fig. 25B). Leg formula: IV, I, II, III. Length of legs and palpal segments (femur, patella, tibia, metatarsus, tarsus, total): I: 17.87, 10.79, 13.69, 13.40, 8.75, 64.50; II: 16.35, 10.18, 12.05, 11.77, 8.94, 59.29; III: 15.69, 9.40, 10.97, 12.79, 8.50, 57.35; IV: 18.34, 10.20, 14.20, 17.91, 9.98, 70.63. Palp: 13.20, 8.35, 10.12, -, 9.92, 41.59. Spinnerets: PMS, 2.90 long, 3.00 apart; PLS, 4.30 basal, 2.90 middle, 4.35 distal. Tarsi I – IV entirely scopulated. Metatarsus I entirely scopulated, II scopulated 90%, III scopulated 50% distally, IV scopulated 40% distally. Stridulatory setae: with claviform stridulating setae on palp trochanter and femur retrolateral face; leg I trochanter and femur prolateral face. Chaetotaxy (left side): femora I 1p; palp 1p; patellae none; tibiae I 1p, 3v; II 1 p, 4v; III 1 p, 5v, 1r; IV 1 p, 6v, 1r; palp 2p, 5v; metatarsi I 4v; II 4 v; III 1 p, 8v, 2r; IV 2 p, 14v, 1r. Genitalia: fused semicircular spermatheca, with a single receptacle strongly sclerotized slightly notched in the middle, four times wider than its height. Spermatheca baseplate divided, widely separated above, each baseplate oblanceolate 3.5 wider than high, inner side smaller than the outer ( Fig. 25E). Variation: some specimens have a wider base up to five times greater than height, young or juveniles can present the superior edge slightly inward in middle. Ventral face smooth. Baseplate division can vary in length ( Fig. 25F). Urticating setae: types I and III arranged in one dorsoposterior patch, black in colour. Type III are located in an oval dorsomedial area extended to posterior. Type I surround the type III area, with intermediates between type III and I in transition areas ( Fig. 25C) .

Colour pattern: In live specimens, adults of both sexes have the carapace orange (pantone 7412c) on almost all the carapace except in the caput, which is pantone process black in colour, and also has a longitudinal line of beaver colour (pantone 4715c) that goes from back of the eyes to the fovea ( Figs. 26A–C); chelicerae dorsally blue whale colour (pantone 533c); ventral coxae, labium, maxillae and sternum black pearl colour (pantone black 6c); abdomen dorsally black with Christine colour setae (pantone 7583c), ventrally black pearl colour. Legs and palpi: femora and patellae black pearl; tibiae orange (pantone 157c); metatarsi I–III black (pantone black 7c) with proximal third rope colour (pantone 876c), IV black (pantone black 7c) with large brandy punch colour (pantone 722c) covering it almost completely; tarsi black (pantone black c) ( Fig. 36E–H). With juveniles of same pattern but paler in colour.

Distribution and habitat: Brachypelma emilia is known from the northern Pacific Coast region on the western side of Sierra Madre Occidental, being found in southern Sonora, Sinaloa, Nayarit and a small area in north-western Jalisco, just on the border of Jalisco with Nayarit. It could also be possibly found in Durango, but there is no evidence for that yet ( Figs 2, 38). It occurs in drier, coastal thorn scrub, grasslands, palm transition to deciduous forest, and into higher elevations of oak forest ( Fig. 26D). It is a fossorial species whose modified or self-excavated burrows can be found under large rocks, under dense thorny thickets, large tree roots or burrows in leafy ground cover, in both forested and moderately disturbed areas. Some can be also found close to houses or human structures, but this is most likely because the spiders lived there before these buildings were constructed. Burrows do not have any silk around the entrance to indicate there is a spider inside. This species is sympatric (overlapping distributions) with a small population of Brachypelma klaasi in south-western Nayarit (Mendoza, personal observation).