Ocyale ghost Jocque M. & Jocqué R. sp. nov.

urn:lsid:zoobank.org:act: 37AAF237-A0C7-40D1-9BA8-6FF3D4864D79

Figs 1, 2, 3 A–F, 4A–D, 5A–F, 6A–C, 7A–C

Diagnosis

Males of O. ghost sp. nov. can be recognized by details of the male palp: the tegulum is restricted to the prolateral side of the bulbus, the distal prong of the palea appendage is much narrower than the proximal one and the MA with the perpendicular prong is rectangular. Females are characterized by the epigyne in which the T-shaped posterior sclerite is fully exposed and not covered with setae as in other species in the genus.

Etymology

The species name ‘ghost’ refers to the fully white appearance of this spider. Additional reference is made to the large white direwolf ‘Ghost’ in Game of Thrones, the first book in the series of fantasy novels A Song of Ice and Fire by George R.R. Martin.

Type material

Holotype

MADAGASCAR: ♂, Mahajanga Prov., Matsedroy, Lake 2, 15°29′33.9″ S, 046°39′04.1″ E, 5 Jul. 2016, 19:55–20:45, hand collected on sandy beach (Fig. 2), S. Wellens leg. (MRAC 245337).

Paratypes

MADAGASCAR: 1 ♀, 2 juvs, same data as holotype (MRAC 245338); 2 ♀♀, 2 juvs, same data as preceding (MRAC 245340); 2 ♀♀, 2 juvs, as preceding (MRAC 245341); 2 ♀♀, 2 juvs, as preceding (MRAC 245342); 1 ♀, as preceding (MRAC 245347); 1 ♂, 6 juvs, as preceding (MRAC 245348); 1 ♂, 3 juvs, as preceding (MRAC 245361); 2 ♀♀, 2 juvs, as preceding (MRAC 245350); 1 ♀, 5 juvs, as preceding except 12 Jul. 2016 (MRAC 245339); 1 ♀, 5 juvs, as preceding except 22 Jul. 2016 (MRAC 245351); 1 ♀, 4 juvs, as preceding except 24 Jun. 2016 (ZBA); 1 ♂, 4 ♀♀, as preceding (ZBA); 1 ♂, 2 ♀♀, 1 juv., as preceding (ZBA).

Description

Male (holotype)

MEASUREMENTS. Total length 15.35; carapace 8.77 long, 2.27 high, 6.58 wide, narrowed to 3.95 in eye region; labium 1.14 wide, 0.79 long; sternum 3.68 long, 3.07 wide.

COLOUR. Alive (Fig. 3 A–E): almost entirely white with slightly contrasting darker spots as in ethanol specimens; eyes surrounded by yellow rings; cheliceral condyle reddish brown. In ethanol (Fig. 4 A–B): fairly different from colouration of live specimens; carapace brownish cream with interrupted black radiating striae, black fovea, two pairs of spots in front of fovea and dispersed irregular spots along margins; PEQ covered with white setae, tegument dark in its anterior half; chelicerae brown with dark setae as seen in frontal view, dark brown with black setae in ventral view; labium dark brown with cream crescent shape along anterior concave margin; sternum with strongly sinuous lateral margins, ending in long, tapered point; with dispersed short dark setae; legs formula IV-III-I-II; uniform cream with dispersed short, dark setae and dark spines; pedipalp: femur, patella and tibia cream, cymbium and bulbus contrasting dark brown; abdomen: dorsum cream with dispersed small dark spots, two reddish apodemes in anterior half and dispersed dark setae, sides and venter uniform cream; spinnerets: ALS dark, PLS and PMS pale on dorsal side, dark on ventral side.

EYES. AME: 0.35; ALE: 0.15; PME: 0.67: PLE: 0.61; eye rows: ALE: 1.51, PME: 1.51, PLE: 2.18.

CHELICERAE. With three teeth on retromargin, one small proximal tooth and one larger distal tooth on promargin.

LEGS. Spination of leg I (identical on both sides): femur pl4, d3, rl2; patella pl1, rl1; tibia pl2, d2, rl2, v2-2-2; metatarsus pl2, rl2, v2-2, dw5. Leg measurements: see Table 1.

PALP (Figs 5 A–D, 6A–C, 7A–B). Tegulum ribbed, developed on prolateral basal part of bulbus; palea with two prongs, proximal one broad and slightly curved, distal one thin and strongly curved; embolus originating on retrolateral part of palea and curved ventrally around it; MA large, with prolateral part a short hook, ventral part subrectangular, perpendicular to the former.

Female (paratype MRAC 245338)

MEASUREMENTS. TL 16.24; carapace 7.95 long, 3.69 high, 6.31 wide, narrowed to 3.69 in eye region; labium 0.92 long, 1.08 wide; sternum 3.33 long, 2.83 wide.

COLOUR. In ethanol (Fig. 4 C–D): dorsal surface of abdomen more uniform cream than in male but with similar dark spots and apodemes; pedipalp as in the male except for unmodified tarsus with dark tip.

EYES. AME: 0.42; ALE: 0.21; PME: 0.67: PLE: 0.60; eye rows: ALE: 1.44, PME: 1.44, PLE: 2.14.

LEGS. Spination of leg I, right (left): femur pl2(5), d3(4), rl3(3); patella pl1(1), rl1(1); tibia pl2(2), d1(1), rl2(2), v2-2-2 (3-2-2); metatarsus pl2(2), rl2(2), v2-2-2(2-2-2), dw5(5). Leg measurements: see Table 1.

EPIGYNE (Figs 5 E–F, 7C). Roughly triangular area surrounded by dense mat of white setae; large and broad inverted T-shaped sclerite, 1.6 times wider than long; spermathecae large, globular; entrance ducts Z-shaped with basal portion slightly sinuous.

Variation

Males: TL 16.76–19.45 (n = 5); females: TL 16.47–22.01 (n = 19).

Distribution

Known only from the type locality (Fig. 1).

Affinities

We placed this species in the genus Ocyale based on the presence of the two elongate curved prongs on the palea (Figs 4B, 5 B–C, 6B), the epigyne surrounded with white hairs and with a wide inverted T-shaped sclerite (Figs 5E, 7C), the large globular spermathecae (Fig. 5F) and the conformation of the copulatory ducts (Alderweireldt 1996: fig. 27). The specimen illustrated by Siyam et al. (2015: figs 13–15) from Sudan is probably not an Ocyale, at least not O. pilosa because the palp does not fit the illustrations of Alderweireldt (1996: figs 12–13). The colour pattern described for the genus in both these papers may be inaccurate based on the observed differences between specimens in ethanol and photos of the living spiders for this new species. This indicates the value of including images of living animals in descriptions of new species. It is not clear to which species the representative of Madagascar is most closely related to.

Biology

Ocyale ghost sp. nov. was only found on the white sandy beaches (Fig. 3 A–B) of an inland lake in the study region. The surveys also included grassland and dry forest, but the species seems restricted to a white-sand habitat, as reflected in its habitus. Ocyale ghost sp. nov. is active at night and all specimens were caught with headlamps after sunset. Captured animals that were kept alive in large ziplock bags overnight constructed retreats in the sand, lined with silk (Fig. 3C). Possible prey include large insects such as grasshoppers (Fig. 3F) that also exhibit camouflage colours as an adaptation to the white beach they live on. Intraspecific predation is also likely to occur (Fig. 3E), a phenomenon which is not unusual among lycosids (Edgar 1969; Hallander 1970). We observed copulation and females with spiderlings (Fig. 3D) in the midst of the dry season (June–July). Juveniles of a complete range of size, from very small ones (6 mm TL) to subadults, were observed, indicating that this species might reproduce yearround. The permanent presence of water in its habitat might explain why this species is also active in the dry season when spider activity is on average very low.