Trachelas mombachensis, Leister, Matthew & Miller, Kelly B., 2015

Leister, Matthew & Miller, Kelly B., 2015, Description of a new tracheline spider, Trachelas mombachensis sp. n., in the T. bispinosus species group from the Mombacho Volcano in Nicaragua (Araneae: Trachelidae), Zootaxa 3936 (1), pp. 141-146 : 143-145

Trachelas mombachensis sp. n.

Figs. 1A–C; 2A, B; 3A–C

Type material. Nicaragua: Granada Dpto: Volcán Mombacho, (11.84°, -85.95°), elev. 700–800 m, “San Joaquin” organic coffee plantation, method of collection malaise trap, J. M. Maes coll., Holotype ♂, ( MSBA 37273), collected 15 December, 1998; Paratype ♀, ( MSBA 37274), collected 15 January, 1999.

Other material examined. Nicaragua: Granada Dpto: Volcán Mombacho, (11° 50’N, 85° 57’W), elev. 700–800 m, “El Progreso” non-organic coffee plantation, method of collection malaise trap, J. M. Maes coll., ( MSBA 37275) 4 ♂, ( MSBA 37277) 1 ♀, collected, 18 August, 1998; ( MSBA 37278) 1 ♀, collected, 30 October, 1998. (11.84°, -85.95°), elev. 700–800 m, “San Joachin” non-organic coffee plantation, method of collection malaise trap, J. M. Maes coll. ( MSBA 37276) 3 ♀, 1 ♂, collected 15 December, 1998.

Etymology. This species is named for its type locality, the Mombacho Volcano, Nicaragua.

Diagnosis. Males of Trachelas mombachensis sp. n. are most similar to T. ecudobus Chickering, 1972 , T. rotundus Platnick & Shadab, 1974 and T. truncatulus F. O. Pickard-Cambridge, 1899 . In these species the pedipalp bulb has only an embolus and conductor, and lacks an additional terminal apophysis. Trachelas mombachensis sp. n. has a slightly twisted embolus that emerges from the tip of the bulb, separating it from T. truncatulus , which has a straight embolus that emerges from slightly below the tip of the bulb. Trachelas mombachensis sp. n. has a wide conductor that curves over the embolus, separating it from T. ecudobus and T. rotundus , which have comparatively thinner straight conductors (Fig. 1A–C).

Females of T. mombachensis sp. n. are most similar to those of T. parallelus Platnick & Shadab, 1974 and T. planus Platnick & Shadab, 1974 in that they all share widely separated copulatory openings. Trachelas mombachensis sp. n. can be separated from T. parallelus by having the lateral ducts extending anteriorly beyond the copulatory openings, whereas the copulatory openings of T. parallelus are situated anteriorly beyond the lateral ducts. Trachelas mombachensis can be separated from T. planus by having the copulatory openings situated at the base of the lateral ducts, whereas the copulatory openings of T. planus are situated such that the lateral ducts extend nearly as far forward as behind the openings.

Description. Male: Total length 4.0 (4.0–4.8). Carapace length 2.5 (2.1–2.6); width 1.6 (1.5–1.9). Carapace dark reddish-brown, granulose, oval, narrowing at cephalic region, anteriorly rounded, covered in thin transparent setae; eight eyes, circular, subequal in size, PER strongly recurved, AER slightly recurved, thoracic groove longitudinal weak; chilum divided ( Fig. 3A, C ).

Chelicerae dark reddish-brown, longer than wide, covered in thin transparent setae; three prominent retromarginal cheliceral teeth with small distal denticle present in some specimens, proximal tooth largest, distal tooth smallest; three prominent promarginal cheliceral teeth, middle tooth largest, proximal tooth smallest.

Sternum dark red-brown, granulose, longer than wide, shield shaped, covered in thin dark, transparent setae. Labium redbrown, trapezoidal, longer then wide, narrowing distally. Endites red-brown, longer then wide, proximally widened, anterolateral spurs present ( Fig. 3B, C ).

Legs I, II reddish-brown; Legs III, IV yellow-brown; legs covered in thin dark setae; legs lacking spines; short, black ventral leg cusp present on tibia and metatarsus I, II; cusp: tibia I 5–12, II 3–9; metatarsus I 7–11, II 3–9; tarsus I 0, II 0. Leg formula: I, IV, III, II.

Abdomen with dorsum light yellow brown, oval, covered in short fine dark setae; orange ill-defined dorsal scutum present, nearly invisible in lighter specimens, longer than wide, darker orange cardiac mark, four dark sigilla ( Fig. 3A, C ).

Ventrally abdomen light yellow-brown, covered in short fine dark setae; ventral scutum orange-brown, oval, wider than long ( Fig. 3B ).

Pedipalp with large rectangular RTA, longer then wide, terminating with small projection; genital bulb yellowbrown, tear shaped, longer than wide, wider than cymbium ventrally, narrowing distally; conductor clear, wide, bent, cupping embolus; embolus short, slightly twisted, emerging from tip of bulb, covered ventrally by conductor (Fig. 1A–C).

Female: Total length 4.7 (4.6–5.0). Carapace length 2.3 (2.3–2.4); width 1.6 (1.5–1.7). Color, form as in male, dorsal scutum absent, ventral leg cusps absent. Ventral epigynum with widely separated copulatory openings; ducts visible through cuticle; ventrally, lateral ducts converge anteriorly, extending beyond copulatory openings; basal enlargements of median ducts visible through cuticle, tear shaped. Vulva dorsally with enlarged lateral ducts angled medially, positioned above globose spermathecae, median ducts enlarged posterolaterally. Coiling of ducts variable among females specimens examined, general position, angle of lateral ducts in relation to copulatory openings, position of spermathecae and median duct expansions remained consistent across specimens examined ( Fig. 2A, B ).

Distribution. Trachelas mombachensis sp. n. is only known from the type locality on the Mombacho Volcano in Nicaragua.

Figures

FIGURES 3 A – C. Trachelas mombachensis sp. n., male habitus: A. Dorsal view; B. Ventral view; C. Lateral view. Abbreviations: Ch—chilum; DS—dorsal scutum; Sp—anterolateral spurs; VS—ventral scutum. (Original illustrations by Matthew Leister).

FIGURES 2 A, B. Trachelas mombachensis sp. n., female genitalia: A. Ventral view of female epigynum; B. Dorsal view of female vulva. Abbreviations: CO—copulatory openings; LD—lateral duct expansion; MD—median duct expansion; ST—spermathecae. (Original illustrations by Matthew Leister).