Arboriticus maculatus Borges, Abegg & Bertani, 2025

Borges, Leandro Malta, Abegg, Arthur Diesel, Paladini, Andressa & Bertani, Rogério, 2025, A new genus and five new species of arboreal tarantulas (Araneae: Theraphosidae) from Brazil, Zootaxa 5679 (4), pp. 521-551 : 542-548

Arboriticus maculatus Borges, Abegg & Bertani gen. nov. sp. nov.

( Figs 1 , 61 –73, 77–79, 82–85)

Gen. sp. 1: Bertani, 2023:14–15, 19, 23.

Diagnosis. Males resemble those of A. celsoi gen. nov. sp. nov. by the reduced male palpal bulb keels (Figs 63– 65) in conjunction with the metatarsus I touching the apex of the retrolateral process when flexed. They can be distinguished from those of A. celsoi gen. nov. sp. nov. by the male palpal bulb keels PS, PI and A slightly reduced, but easy to see, presence of R keel (Figs 63–65), and rounded sternum (Fig. 62). Females can be distinguished from those of all other species by the non incrassate metatarsus IV lacking stiff setae and the two spermathecae fused by a short sclerotized area (Fig. 71).

Etymology. The specific epithet “maculatus ” is a Latin word for “spotted”, referring to the small black spots on the legs of the specimens of this species.

Type material. Holotype male ( MNRJ 9041 ), RPPN Estação Veracel (16°23'15.71"S, 39°10'11.04"W), Porto Seguro, Bahia, Brazil, A. D. Abegg col., I.2016 ; Paratype female ( MNRJ 9042 ), same data ; Paratype male from Brazil, state of Bahia, Ilhéus , CEPLAC [14º46’S, 39º13’W] 43 m a.s.l., R. Bertani col., April 1998 ( IBSP 12471 ) ; Paratype male, same locality, A. D. Brescovit col., April 1998 ( IBSP 12472 ) ; Paratype female, Brazil, state of Bahia, Porto Seguro , CEPLAC [16º23’S, 39º10’W] 87 m a.s.l., R . Bertani, April 1998 ( IBSP 12473 ) ; Paratype female, Brazil, state of Bahia, Porto Seguro, Arraial d’Ajuda [16º29’S, 39º04’W], A. Chagas Jr, without data ( MNRJ 12951 ) .

Other material examined. BRAZIL: Bahia : Porto Seguro, Parque Nacional do Pau Brasil [16º27’ S, 39º17’ W], 3 males, H. Gonzales-Filho et al. col., 24–28.III.2022, ( CAD 1283, CAD 1284, CAD 1285) .

Description. Holotype male ( Figs 61 –68, 78) MNRJ 9041. Carapace 15.12 long, 14.24 wide, chelicerae 7.49. Legs (femur, patella, tibia, metatarsus, tarsus, total): I: 16.31, 7.56, 14.20, 14.19, 8.51, 60.77. II: 15.58, 7.06, 13.16, 14.12, 8.39, 58.31. III: 13.10, 5.90, 11.04, 13.61, 7.04, 50.69. IV: 15.90, 6.17, 15.37, 20.12, 7.56, 65.12. Palp: 9.03, 4.67, 8.38, –, 3.46, 23.54. Midwidths: femora I–IV = 2.52, 2.20, 2.73, 2.35, palp = 1.56; patellae I–IV = 2.50, 2.32, 2.45, 2.40, palp = 2.27; tibiae I–IV = 2.03, 1.66, 1.78, 1.72, palp = 2.44; metatarsi I–IV = 1.21, 1.26, 1.12, 1.20; tarsi I–IV = 1.20, 1.19, 1.04, 1.05, palp = 1.88. Abdomen 17.93 long, 14.17 wide. Spinnerets: PMS, 1.58 long, 0.67 wide, 1.50 apart; PLS, 2.67 basal, 1.81 middle, 2.73 distal; midwidths 1.02, 0.92, 0.66, respectively.

Carapace ( Fig. 61 ): 1.06 longer than wide; cephalic area moderately raised. Fovea: Slightly recurved, 2.13 wide. Eyes and eye tubercle: Tubercle 0.83 high, 1.86 long, 2.57 wide. Clypeus 0.22 wide. Sizes and inter-distances: AME 0.55, ALE 0.60, PME 0.38, PLE 0.61, AME–AME 0.37, AME–ALE 0.26, AME–PME 0.15, ALE–ALE 1.70, ALE–PME 0.47, PME–PME 1.26, PME–PLE 0.10, PLE–PLE 1.81, ALE–PLE 0.27, AME–PLE 0.48. Eye group 2.52 wide, 1.27 long. Maxillae: Length 4.42, width 2.52. Cuspules: ca. 212 spread over ventral inner heel. Labium: 1.78 long, 2.51 wide, with ca. 107 cuspules spaced by ca. one diameter from each other on the anterior third center (Fig. 62). Chelicerae. Basal segment with 13 teeth in row on promargin and denticles in basal area. Sternum: 6.95 long, 5.70 wide. Sigilla: first and second pairs rounded, third ovals, all less than a diameter from margin (Fig. 62).

Legs: formula I= IV II III. Length leg IV to I: 1.07. Scopula: Tarsi I – IV fully scopulate. Metatarsi I – II fully scopulate; III 1 /2, IV 1 /6 distal scopulate. Metatarsus IV divided by row of 2–3 setae. Spination: palp: femur p0-0-1, patella p2; tibia p2-3-1, leg I: femur p0-1-2, patella p1, tibia v2-2-1, p1-1-1, r1-1-1, metatarsus v0-0-1ap, p1-0-0; leg II: femur p0-2-2, r0-0-1, patella 0, tibia v2-3-3ap, p1-2-1, r1-1-1, metatarsus v1-0-2ap; leg III: femur p0-2-0, r0-1-1, patella 0, tibia v4-4-3ap, p2-1-1, r1-1-1, metatarsus v1-3-4ap, p1-1-1, r0-1-1; leg IV: femur p0-0-1, patella 0, tibia v3-3-5(2ap), p1-1-1, r1-0-2; metatarsus v16(3ap), p0-1-1, r0-1-1. Spiniform setae: a few spiniform setae on the superior areas of retrolateral maxillae and coxae I and II. A few, sparse spiniform setae on the inferior edge of prolateral coxae I– IV. STC: a single row of 0–5 small teeth on legs I– IV. Urticating setae: Only type I present, position and length range: MA, 0.34–0.37. Distribution of urticating setae on the abdomen dorsum unknown due to a large bald area .

Palp (Figs 63–65). Bulb pyriform, embolus slightly longer than tegulum length, slightly flattened at distal region, apex narrowing abruptly, forming a more or less straight distal portion. Prolateral keels present. PS forming embolus edge distally. PI not reduced. A keel short, directed prolaterally. R present, not pronounced. SA absent.

Bifid tibial spur (Figs 66–68) with two straight processes originating from common base, RP longest. A single, flattened, rhomboidal spine contiguous to the internal upper face of the RP and another on the internal face of the PP. Metatarsus I curved at its basal third, when folded touches the retrolateral side of the RP (Fig. 66).

Color pattern (in alcohol): Carapace, chelicerae, legs, coxae, labium and maxillae light brown with some yellowish brown long setae. Tibiae and metatarsi dorsally with series of small dark spots. Abdomen dorsally black with long yellowish brown setae, ventrally yellowish brown. Femora, patellae, tibiae and metatarsi of legs and palp with very discrete light stripes. Apex of leg and palp segments with very discrete whitish rings on apex.

Description. Paratype female (MNRJ 9042) ( Figs 69 –73, 79). Carapace 16.86 long, 14.54 wide, chelicerae 9.41. Legs (femur, patella, tibia, metatarsus, tarsus, total): I: 12.75, 7.39, 10.63, 9.46, 6.10, 46.33. II: 11.93, 6.30, 8.99, 8.58, 5.77, 41.57. III: 10.33, 5.64, 8.23, 9.48, 5.11, 38.79. IV: 12.54, 5.92, 11.10, 13.40, 5.66, 48.62. Palp: 9.09, 5.31, 7.07, –, 6.76, 28.23. Midwidths: femora I–IV = 2.35, 2.48, 2.72, 2.46, palp = 1.74; patellae I–IV = 2.93, 2.85, 2.62, 2.75, palp = 2.41; tibiae I–IV = 2.48, 2.28, 2.21, 2.26, palp = 2.07; metatarsi I–IV = 1.86, 1.77, 1.75, 1.47; tarsi I–IV = 1.69, 1.68, 1.74, 1.66, palp = 2.01. Abdomen 18.01 long, 13.71 wide. Spinnerets: PMS, 1.58 long, 0.80 wide, 1.41 apart; PLS, 3.02 basal, 1,53 middle, 2.59 distal; midwidths 1.26, 1.02, 0.81, respectively.

Carapace ( Fig. 69 ): 1.16 longer than wide; cephalic area noticeably raised. Fovea: Straight, 3.29 wide. Eyes and eye tubercle: Tubercle 0.60 high, 2.04 long, 2.80 wide. Clypeus 0.25 wide. Eye sizes and inter-distances: AME 0.63, ALE 0.64, PME 0.40, PLE 0.62, AME–AME 0.38, AME–ALE 0.27, AME–PME 0.15, ALE–ALE 1.92, ALE–PME 0.33, PME–PME 1.36, PME–PLE 0.08, PLE–PLE 1.92, ALE–PLE 0.26, AME–PLE 0.48. Eye group 2.62 wide, 1.36 long. Maxillae: Length 5.48, width 3.13. Cuspules: ca. 284 spread over ventral inner heel. Labium 2.22 long, 2.86 wide, with 115 cuspules spaced by ca. one diameter from each other on the anterior third center (Fig. 70). Chelicerae: Basal segment with 13 teeth in row on promargin and denticles on basal area. Sternum: 6.88 long, 6.43 wide. Sigilla: first and second pairs rounded, third ovals (Fig. 70).

Legs: formula I= IV II III. Length leg IV to leg I: 1.05. Scopula: Tarsi I – IV fully scopulate. Metatarsi I – II fully scopulate; III 1 /2, IV 1 /6 distal scopulate. Metatarsus IV divided by row of 3–4 setae. Spination: palp: femur p0-0- 1, patella 0, tibia v0-2-4ap, p0-2-1; leg I: femur p0-0-1, patella 0, tibia v0-1-3, p0-1-0, metatarsus v0-0-1ap; leg II: femur p0-0-1, patella 0, tibia v0-1-2ap, p0-1-0, metatarsus v0-0-3ap, p0-1-0; leg III: femur p0-0-1, r0-0-1, patella 0, tibia v0-2-2ap, p1-1-1, r1-1-1, metatarsus v0-2-3ap, p0-1-1, r0-1-1; leg IV: femur r0-0-1, patella 0, tibia v0-5- 2ap, p1-1-0, r1-1-1, metatarsus v17(4ap), p0-1-2, r0-1-1. Spiniform setae: a few spiniform setae on the retrolateral superior area of maxilla and coxa I, none on coxa II, a row of few spiniform setae on basal area of coxa III, from superior to middle region. Prolateral coxae I– II with small spiniform setae, few larger spiniform setae on edge of inferior coxae III – IV (Figs 72–73). STC: a single row of 4–7 small teeth on legs I– IV. Metatarsus and tibia IV unmodified. Urticating setae: Only type I present, position and length range: LA, 0.21–0.22, LM, 0.23–0.24, LP, 0.25–0.28, MA, 0.26–0.27, MM, 0.46–0.50, MP, 0.34–0.42. Distribution of setae on abdomen dorsum as fig. 5 in Bertani &Guadanucci (2013) .

Spermathecae: Two short spermathecae heavily fused by a short sclerotized area, spermathecal stalk as wide as spermathecal bulb (Fig. 71).

Color pattern (in alcohol): Carapace, chelicerae and legs light brown. Legs with pinkish long setae. Tibiae and metatarsi dorsally with series of small dark spots. Tarsi dorsally brown with orange setae. Coxae of legs, labium and maxillae brown with short orange setae. Abdomen dorsally black with long reddish setae, ventrally yellowish brown. Femora, patellae, tibiae and metatarsi of legs and palp with very discrete light stripes. Apex of leg and palp segments with very discrete whitish rings on apex.

Distribution. Known only from five close localities in the southern half of the state of Bahia Coast, Brazil ( Fig. 1 ).

Natural history. Many specimens were observed on tree trunks and moving between branches during fieldwork. Adult specimens were found occupying cavities in tree trunks, between 1.5 and 2.5 meters in height from the ground (Figs 82–84).

Figures

FIGURE 1. Map of Brazil showing geographic records of Arboriticus gen. nov. species. Dots represent type localities, squares additional localities, and triangles correspond to records of undetermined collected specimens, which are likely undescribed species.

FIGURES 61─68. Arboriticus maculatus gen. nov. sp. nov., holotype male. 61, carapace and chelicerae, dorsal. 62, sternum, labium, maxillae, and coxae, ventral. (63–65) left palp bulb. 63, prolateral. 64, retrolateral. 65, dorsal. (66─68) left tibial apophysis. 66, retrolateral. 67, prolateral. 68, ventral. Scale bar = 1 mm.

FIGURES 69─73. Arboriticus maculatus gen. nov. sp. nov., paratype female. 69, carapace and chelicerae, dorsal. 70, sternum, labium, maxillae, and coxae, ventral. 71, spermathecae, dorsal. 72, coxa III (retrolateral) showing spiniform setae (arrow). 73, coxa IV, prolateral, showing spiniform setae (arrow). Scale bar = 1 mm.