Melloina pacifica sp. nov.

Figs 11, 12, 13, 14, 15, 16, 17, 18, 19

Type material.

Holotype ♂: Colombia, Chocó, Bahía Solano, Jardín Botánico del Pacífico, 6.38, -77.40, 45 m a.s.l., 10-25 February 2022, M. Echeverri, S. Gómez Torres and C. Perafán leg. (ICN 12358). Paratypes, same data as holotype except elevation, 99-145 m a.s.l.: ♀ (ICN 12359), ♂ (ICN 12360), ♂ (ICN 12361), ♀ (ICN 12362), ♂ (ICN 12363).

Etymology.

The specific epithet Melloina pacifica is a noun in feminine refers to the Colombian Pacific region, where the species is distributed.

Diagnosis.

Male of Melloina pacifica sp. nov. can be distinguished from other Melloina species by the relatively longer embolus (Fig. 17), ca. 2 × the tegulum length (<2 × in M. gracilis (Schenkel, 1953),> 3 × in M. santuario Bertani, 2013), by the labium with numerous cuspules (112 vs. 60-80 in other known species), and by the tarsi II, III, IV ventrally cracked at midpoint (III and IV in M. gracilis, only IV in M. santuario). Additionally, differs from M. santuario by the number of spines on tarsi I and II (two rows of 8-10 spines vs. 4 or 5 in M. santuario, similar in M. gracilis 9-12). Female can be distinguished from other Melloina species by the straight, long, and wide spermathecae, without glandular area in the basal third (Fig. 19C), numerous maxillary cuspules (160 vs. 129/141 in M. gracilis, 82/90 in M. santuario, and 60 in M. rickwesti Raven, 1999), and labium with 98 cuspules (77 in M. santuario, ca. 90 in other species).

Distribution.

Known only from the type locality (Figs 1, 2).

Description.

Male (holotype) (Figs 11 - 17). Total length: 16.1. Chelicerae basal segment: length 2.1, width 1.4. Carapace: elongated, length 7.7, width 7.0; cephalic area slightly raised. Abdomen: ovoid, length 7.5, width 3.7. Spinnerets: PLS with three segments, total length 2.52 (basal 0.82, middle 0.75, apical digitiform 0.95); PMS with one segment, length 0.45. (Fig. 12).

Clypeus: absent. Ocular tubercle (Fig. 12E): ovoid, raised, forwardly directed, length 1.04, width 1.78. Anterior eye row procurved, posterior eye row slightly recurved. Eye diameters and interdistances: AME 0.39 (circular), ALE 0.46 (oval), PME 0.30 (oval), PLE 0.35 (oval), AME-AME 0.09, AME-ALE 0.19, PME-PME 0.72, PME-PLE 0.09, PLE-PLE 1.31, ALE-PLE 0.11, AME-PME 0.05. Thoracic fovea (Fig. 12E): transverse, straight, deep, width 2.19; 4.41 from the anterior edge of carapace. Chelicerae basal segment: spiniform setae on three rows on dorsal area and some dispersed on lateral areas, with 15 left/ 14 right well-developed teeth on each furrow promargin, and a group of ca. 43 small teeth near last three basal promargin teeth. Intercheliceral tumescence absent. Fang long. Maxillae (Fig. 13): longer than wide, trapezoidal, with ca. 111 left / 108 right cuspules, spaced, largely spread but more dense over ventral inner heel; the distal prolateral lobe conical and the proximal posterior angle projected. Labium (Fig. 13): sub-rectangular, length 0.77, width 1.15, with ca. 112 cuspules on anterior edge, evenly distributed. Labio-sternal junction: narrow in the midline with two oval sigillae touching and extended to the edge. Sternum (Fig. 13A): rounded, anterior edge with a semicircular area slightly raised (joined to labio-sternal groove), length 3.25, width 3.08, with three pairs of inconspicuous sigillae sclerotized. Sigillae: proximal pairs subcircular, submarginal; distal pair oval, marginal.

Legs pattern: IV>I>II>III. Lengths of legs and palpal segments on Table 3. Tarsal claws: STC long, with row of three or four small teeth, ITC absent on all legs. Claw tufts: weak, present in all tarsi (Figs 14C, D, 15, 16). Tarsal scopulae: pseudoscopula present, tarsi I and II distally with weak pseudoscopulae (Figs 14C, D, 15, 16), III with a few distal sparse setae, IV without scopulae. Metatarsal scopulae: absent in all metatarsi. Trichobothria: filiform of different sizes and clavate in all tarsi, I and II with ca. 22 filiform and ca. 12 clavate, III and IV with ca. 20 filiform and ca. eight clavate; filiform trichobothria also present in all metatarsi and tibia, including palpal tibia. Tarsi II, III, IV ventrally cracked at midpoint. Plumose setae on retrolateral face of femur IV: absent. Stridulatory bristles: absent. Body with strongly pilose setae. Book lung openings oval and sclerotized. Urticating setae: absent.

Spination (proximal to distal). Femora: palp d 5-8-11, p 0-0-3, v 0-2-0, r 0-2-2; I d 6-4-10, p 0-0-3, v 3-4-10 (8 ap), r 0-0-5; II d 5-5-7, p 0-0-1, v 0-0-6 (5 ap), r 1-1-1; III d 5-5-4, p 3-2-2, v 1-3-10 (8 ap), r 1-2-3; IV d 5-2-4, p 0-0-1 ap, v 0-2-10 (8 ap), r 0-1-1. Patellae: palp d 9-7-8, p 0-1-4 ap, v 1-1-4 ap, r 2-3-2; I d 1-1-3, p 1-1-2, v 0-0-2 ap, r 1-1-2 ap; II d 3-2-5, p 1-2-5 (4 ap), v: 0-1-3 ap, r: 1-1-2; III d: 5-4-5, p: 2-2-2, v: 0-2-2 ap, r: 1-1-3 ap; IV d: 3-1-2, p: 0-1-2 ap, v 0-2-3 (2 ap), r 0-0-1 ap. Tibiae: palp d 2-5-5, p 4-2-4 (2 ap), v 5-6-7 (3 ap), r 2-3-8 (2 ap); I d 1-1-3, p 1-1-2, v 0-0-2 ap, r 1-1-2 ap; II d 2-1-1, p 3-2-3 (2 ap), v 4-4-4 (2 ap), r 2-2-0; III d 3-2-3, p 3-2-3 (1 ap), v 2-2-2 ap, r 3-3-3 ap; IV d 7-5-7, p 5-4-4 (1 ap), v 3-2-3 (2 ap), r 2-2-2 (1 ap). Metatarsi: I d 0, p 2-2-1 ap, v 6-4-6 (2 ap), r 1-1-1; II d 2-2-2, p 4-4-4 (1 ap), v 4-5-6 (3 ap), r 3-2-2 (1 ap); III d 4-4-3, p 2-2-2, v 4-4-5 (2 ap), r 2-3-3 (1 ap); IV d: 3-1-4, p: 2-2-2, v: 3-3-4 (2 ap), r: 3-2-2 (1 ap). Tarsi: cymbium p lobe 4, r lobe 10 (8 ap); I d 0, p 3-1-4 (1 ap), v 0, r 3-3-4 (1 ap); II d 1-1-1, p 3-3-4 (1 ap), v 0, r: 3-3-4 (1 ap); III d 3-2-3, p 3-3-4 (1 ap), v 0, r 3-3-4 (1 ap); IV d 3-4-3, p 2-3-3 (1 ap), v 2-1-2, r 2-3-3 (1 ap).

Palp (Fig. 17): palpal bulb pyriform, embolus long, thin, filiform at apex (Fig. 17A-D); cymbium of two dissimilar lobes, distally spinose (Fig. 17E, F); tibia with shallow distoventral groove. Tibial apophysis (Fig. 14E): composed of two unequal branches originating from common base; retrolateral branch longest, distally curved, with two large subapical spines, one internal and one external; prolateral branch straight, small, with a very large basal spine, longer than its length. Metatarsus I straight, when flexed it passes on the retrolateral side of the apophysis.

Coloration. Living spider: carapace, palp, and legs reddish black; femora and tarsi red, distal femora, patellae, tibiae, and metatarsi black; abdomen dark (Fig. 11). In alcohol: carapace reddish brown; palp and legs brown; distal femora, patellae, tibiae, and metatarsi dark brown; abdomen greyish brown.

Female (paratype - ICN 12359) (Figs 18, 19). Total length: 18.1. Chelicerae basal segment: length 2.0, width 1.7. Carapace: elongated, length 8.2, width 7.2; cephalic area slightly raised. Abdomen: ovoid, length 9.1, width 5.8. Spinnerets: PLS with three segments, total length 2.73 (basal 0.91, middle 0.75, apical digitiform 1.07); PMS with one segment, length 0.69. (Fig. 18).

Clypeus: absent. Ocular tubercle (Fig. 18E): ovoid, raised, forwardly directed, length 1.24, width 2.04. Anterior eye row procurved, posterior eye row slightly recurved. Eye sizes and interdistances: AME 0.32 (circular), ALE 0.48 (oval), PME 0.23 (circular), PLE 0.37 (oval), AME-AME 0.09, AME-ALE 0.14, PME-PME 0.8, PME-PLE 0.09, PLE-PLE 1.57, ALE-PLE 0.13, AME-PME 0.06. Thoracic fovea (Fig. 18E): transverse, straight, deep, width 2.51; 5.48 from the anterior edge of carapace. Chelicerae basal segment: spiniform setae on three rows on dorsal area and some dispersed on lateral areas, with 16 well-developed teeth on each furrow promargin, and group of ca. 43 small teeth near last three basal promargin teeth. Fang long. Maxillae (Fig. 19B): longer than wide, with the anterior prolateral lobe conical with ca. 160 cuspules, spaced, largely spread but more dense over ventral inner heel; the distal prolateral lobe conical and the proximal posterior angle projected. Labium (Fig. 19B): sub-rectangular, length 1.02, width 1.73, with ca. 98 cuspules on anterior edge distributed with higher density towards the lateral sides. Labio-sternal junction: narrow in the midline with two oval sigillae touching and extended to the edge. Sternum (Fig. 19A): rounded, anterior edge with a semicircular area slightly elevated (joined to labio-sternal groove), length 3.49, width 3.75, with three pairs of conspicuous sclerotized sigillae. Sigillae: proximal pair subcircular, submarginal; distal pairs oval, submarginal.

Legs pattern: IV>I>II>III. Lengths of legs and palpal segments on Table 4. Tarsal claws: STC long, with row of 2-4 small teeth, ITC absent on all legs. Claw tufts: weak, present in all tarsi. Tarsal scopulae: absent in all legs. Metatarsal scopulae: absent in all legs. Trichobothria: filiform of different sizes and clavate in all tarsi, I-IV with ca. 20 filiform, I-III with ca. ten clavate, IV with ca. seven clavate; filiform trichobothria also present in all metatarsi and tibia, including palpal tibia. Tarsus IV cracked at midpoint. Plumose setae on retrolateral face on femur IV: absent. Stridulatory bristles: absent. Body with strongly pilose setae. Book lung openings oval and sclerotized. Urticating setae: absent.

Spination (proximal to distal). Femora: palp d 2-2-4, p 0-0-1, v 12-9-8, r 0; I d 3-2-3, p 0, v 3-3-5, r 0; II d 1-0-1, p 0, v 4-3-3, r 0; III d 1-2-1, p 1-1-1, v 1-2-3, r 0; IV d 1-1-1, p 0, v 1-2-6, r 0. Patellae: palp d 3-2-3, p 1-1-3 ap, v 0-0-3 ap, r 0-1-2; I d 0, p 0-1-1, v 0-2-2 ap, r 1-1-0; II d 0, p 0, v 0-2-2 ap, r 0; III d 0-1-0, p 0-1-1, v 0-1-2, r 0; IV d 0, p 0, v 0-2-3 (2 ap), r 0. Tibiae: palp d 5-5-3, p 0-1-2, v 6-5-3 ap, r 2-2-2; I d 4-6-4, p 2-1-2, v 3-4-2 ap, r 1-1-1; II d 2-1-1, p 1-1-2, v 4-5-4 (2 ap), r 1-1-1; III d 4-5-5, p 2-2-2, v 3-4-4 (3 ap), r 0-1-1; IV d 2-2-2, p 3-2-1 ap, v 4-5-5 (1 ap), r 1-1-2 (1 ap). Metatarsi: I d 0, p 1-1-0, v 5-5-6 (2 ap), r 0; II d 0, p 1-1-3, v 5-3-5 (2 ap), r 1-2-2 (1 ap); III d 2-3-4, p 2-2-2 (1 ap), v 4-3-3 (1 ap), r 2-2-2; IV d 4-4-4, p 2-2-1, v 4-3-4 ap, r 2-2-2. Tarsi: palp d 0, p 3-3-3, v 1-3-0, r 2-3-2; I d 0, p 3-3-4, v 0-0-2 ap, r 2-3-2; II d 0, p 3-3-3 (1 ap), v 0, r 3-3-3; III d 0, p 3-3-3, v 0, r 3-4-3; IV d 0, p 3-3-4 (1 ap), v 0-3-0, r 4-3-4 (1 ap).

Spermatheca (Fig. 19C): two seminal receptacles digitiform, straight, long, and wide, without glandular area in the basal third.

Coloration. In alcohol: as described in the male.

Remarks.

Melloina pacifica sp. nov. is the first species of the genus described for Colombia, although it is known that Melloina is distributed in different ecosystems, including cave environments ( Perafán 2017; Pérez-Miles et al. 2019). Males were captured actively walking at night and females were captured in shallow burrows, especially muddy ground. This record expands the geographical distribution of the genus, recorded previously only for Venezuela and Panama (WSC 2023). We confirmed the presence of pseudoscopulae in the anterior tarsi of males, as reported by Pérez-Miles et al. (2017). In the present work, M. pacifica sp. nov. is included within Theraphosidae according to phylogenetic analysis of Mori and Bertani (2020) and the preliminary results of Pérez-Miles et al. (2019). It should be noted, as mentioned by other authors, Melloina is a distinctive taxon since it is the only one with the exclusive combination of claw tufts and tarsal pseudoscopulae (only in males). Additionally, its taxonomic position is currently being widely debated (Raven 1985; Pérez-Miles et al. 2019; Mori and Bertani 2020; Goloboff-Szumik and Ríos-Tamayo 2022).