Eriauchenius rangita, Wood, Hannah M. & Scharff, Nikolaj, 2017

Wood, Hannah M. & Scharff, Nikolaj, 2017, A review of the Madagascan pelican spiders of the genera Eriauchenius O. Pickard-Cambridge, 1881 and Madagascarchaea gen. n. (Araneae, Archaeidae), ZooKeys 727, pp. 1-96 : 1

Eriauchenius rangita sp. n. Figs 7, 30

Type material.

Male holotype: Madagascar, Antananarivo, NE outskirts Antananarivo, Ambohimanga Village, 27 Jul 1992, cryptic searching, V. & B. Roth (deposited in CAS; CASENT9010053).

Other material examined.

MADAGASCAR: Female paratype, Fianarantsoa, Forêt d’Atsirakambiaty, 7.6 km 285° WNW Itremo, 20°35'36"S, 46°33'48"E, 1550 m., 22-26 Jan 2003, montane rainforest, general collecting day, includes one hatched eggcase, Fisher, Griswold et al. (CASENT9005939); 1F, Fianarantsoa, Forêt d’Atsirakambiaty, 7.6 km 285° WNW Itremo, 20°35'36"S, 46°33'48"E, 1550 m., 22-26 Jan 2003, montane rainforest, general collecting day, includes one hatched eggcase, Fisher, Griswold et al. (CASENT9005772); 1F, Fianarantsoa, Forêt d’Atsirakambiaty, 7.6 km 285° WNW Itremo, 20°35'36"S, 46°33'48"E, 1550 m., 22-26 Jan 2003, montane rainforest, general collecting night, includes one hatched eggcase, Fisher, Griswold et al. (CASENT9016773); 1F,1Juv, Fianarantsoa, Forêt d’Atsirakambiaty, 7.6 km 285° WNW Itremo, 20°35'36"S, 46°33'48"E, 1550 m., 22-26 Jan 2003, montane rainforest, general collecting, beating and puffing spiders, Fisher, Griswold et al. (CASENT 9018883); 1F, Fianarantsoa, Forêt d’Atsirakambiaty, 7.6 km 285° WNW Itremo, 20°35'36"S, 46°33'48"E, 1550 m., 24 Jan 2003, montane rainforest, within fallen palm frond, includes one eggcase, Fisher, Griswold et al. (CALENT9005822); 1M,2F, Toliara, Réserve Spéciale d’Ambohijanahary, Forêt d’Ankazotsihitafototra, 35.2 km 312° NW Ambaravaranala, 18°16'00"S, 45°24'24"E, 1050 m., 13-17 Jan 2003, montane rainforest, general collecting night, Fisher, Griswold et al. (CASENT9018159); 1M, Toliara, Réserve Spéciale d’Ambohijanahary, Forêt d’Ankazotsihitafototra, 35.2 km 312° NW Ambaravaranala, 18°16'00"S, 45°24'24"E, 1050 m., 13-17 Jan 2003, montane rainforest, general collecting day, Fisher, Griswold et al. (CASENT9018251).

Etymology.

The specific name is a noun in apposition and commemorates Queen Rangita.

Diagnosis.

Males and females are considered part of the " workmani group" based on having a single dorsal protuberance on the abdomen (a triangular shaped abdomen) (Fig. 7A). Males are distinguished from all other species in the " workmani group" by the shape of the MA that has two bifurcations, one deep and one shallow (Fig. 7C). Females are distinguished from E. andriamanelo by lacking the heavily sclerotized “T” shaped structure on the posterior of the bursa, from E. andrianampoinimerina by lacking the strong abdomen markings and by the “neck” having a tilt angle that is less than 80°, and from E. ranavalona by lacking the lime-green abdomen markings. Females are indistinguishable from the remaining " workmani group" species.

Description.

Male holotype (CASENT9010053, from Ambohimanga Village, Madagascar). Total length 4.15, carapace 1.58 long, 1.37 wide. Abdomen 2.44 long, 2.74 high, with a prominent dorsal hump. Carapace tilt angle 71.52°, tilt height (CtH) 3.64, constriction 0.50, head length 1.50, neck length 2.09. CtH divided by carapace length 2.30. Cephalon with AME on a large bulge and 4 post-ocular protrusions on the apex of the cephalon (Fig. 7A), each provided with a short modified spine at the tip. Chelicerae 3.69 long, with seta 0.52 from base of chelicerae (Fig. 7A). Femur I 6.93 long. Sternum 1.11 long, 0.59 wide. Carapace, chelicerae, sternum, coxae and femora I & II reddish dark brown with many white setae. Legs III & IV yellowish brown, with darker annulations on femora, tibiae and metatarsi. Abdomen yellowish brown, mottled with grayish brown, and light brown book-lung covers, all covered with many white setae (Fig. 7A). Pedipalpal tegulum of the " workmani group" form, with apical conductor encircling a pit-like cavity (Fig. 7 D–K). Conductor tip is a broad triangular point similar to other " workmani group" species except E. andriamanelo (Fig. 3H), where the conductor is divided. MA with a broad unsclerotized transparent base and two apical sclerotized processes, one forked and the other un-forked, so the MA looks tri-forked in the unexpanded palp (Fig. 7C, G, J–K). Embolus similar to other " workmani group" species, being broad and complex with the sperm duct opening in the middle and sclerotization only at the tip (Fig. 7E, H, K).

Female paratype (CASENT9005939). Total length 4.17, carapace 1.66 long, 1.36 wide. Abdomen 2.32 long, 1.94 wide, 2.52 high, with dorsal hump. Carapace tilt angle 75.0°, tilt height (CtH) 3.55, constriction 0.46, head length 1.43, neck length 2.06 (Fig. 2). CtH divided by carapace length 2.14. Cephalon as in male. Chelicerae 3.52 long, and with spine 0.41 from base of chelicerae. Femur I 7.21 long. Sternum 1.05 long, 0.55 wide. Colors as in male, but abdomen generally darker and without clear pattern. Female internal genitalia indistinguishable from other " workmani group" species (Fig. 7B, L).

Variation.

Total length 3.70-4.17 (males; n=3), 4.30-4.84 (females; n=5); Carapace length 1.47-1.66 (males; n=3), 1.63-1.94 (females; n=5); Femur I 4.3-4.39 times the length of carapace in males (n=3) and 3.22-3.55 times the length of carapace in females (n=5). CtH divided by carapace length 2.13-2.31 in males (n=3), 2.19-2.31 in females (n=5). Average femur I length 6.82 (males; n=3), 6.04 (females; n=5).

Natural history.

Specimens have been collected in montane rainforest through general collecting day and night, 'cryptic searching’, and within a fallen palm frond, at altitudes of 1050-1550 m above sea level. Several specimens have been collected with separate eggsacs that are almost the size of the spider and contains 30-40 relatively large white eggsacs wrapped in thin transparent silk. A couple of hatched eggsacs have also been collected.

Distribution.

Known only from central Madagascar (Fig. 30).