Oecobius eberhardi, Santos & Gonzaga, 2008

Santos, Adalberto J. & Gonzaga, Marcelo O., 2008, Two new Neotropical spiders of the genera Oecobius and Platoecobius (Araneae: Oecobiidae), Zootaxa 1786 (1), pp. 61-68 : 62-63

Oecobius eberhardi new species

Figures 1–7

Type material. Holotype: Male from near Cañas (10 o 25’N, 85 o 05’W), province of Guanacaste, Costa Rica, November 1982, W.G. Eberhard coll., deposited in MCZ 52193 . Paratypes: Male and female from the same locality as the holotype, 25 November 1982, W.G. Eberhard coll., deposited in IBSP 79530 . Female from Playa Hermosa (9 o 46’N, 85 o 16’W), province of Guanacaste, Costa Rica, November 1981, deposited in MCZ 52195 .

Etymology. The specific name is a patronym in honour of the collector of the type material, William G. Eberhard, in recognition of his extensive contributions to arachnology in the Neotropics.

Diagnosis. The males of Oecobius eberhardi differ from all the remaining species of the genus by the long, curved and strongly sclerotised embolus with an anterior projection ( Figs. 1, 2 ) and by the oecobiid teg- ular lobe 1 partially covering the anterior part of the tegulum in retrolateral view ( Fig. 3 ). Females can be recognised by the epigynum with an anterior sclerotised plate delimiting a median hyaline area containing an inconspicuous copulatory opening ( Fig. 5 ). Internally, the female genitalia have a median and anteriorly directed copulatory atrium, leading to a pair of stout, diverging copulatory ducts ( Figs. 6, 7 ). In other species of Oecobius the copulatory ducts are thin and poorly sclerotised and the copulatory openings are posteriorly directed, without an internal atrium ( Shear 1970; Baum 1972; 1970).

Description. Male (holotype, MCZ 52193) Carapace dark gray, darker on the margins and with three pairs of lateral triangular black spots. Clypeus dark grey, with a pair of longitudinal, divergent dark bands. Chelicerae dark grey; labium, endites and sternum grey. Pedipalp cream-coloured, distally with a narrow transverse dark stripe covering dorsal and lateral surfaces of the femur, patella and tibia. Leg coxae, trochanters and femora white, with large lateral dark spots; tibiae and metatarsi white, with median and apical dark rings; tarsi orange. Abdomen dorsally black with large cream-coloured spots; sides black; venter grey. Spinnerets cream-coloured, with lateral dark grey spots. Tegulum prolaterally reduced ( Fig. 1 ). Conductor hyaline, arising from anterior half of oecobiid tegular apophysis ( Fig. 2 ). Total length 1.7. Carapace 0.7 long, 0.7 wide. Tibia I length 0.35, II 0.3, III 0.4, IV 0.42. Abdomen 0.9 long, 0.7 wide.

Female (paratype, IBSP 79530). Coloration as in male, except for sparse guanine spots on the dorsum of the abdomen ( Fig. 4 ). Epigynum strongly wrinkled posteriorly, with a grey spot in the middle of the hyaline area ( Fig. 5 ). Internal genitalia delimited anteriorly by a pair of hoods close to the petiole. Copulatory ducts strongly sclerotised, connected to the spermathecae by short, coiled hyaline ducts ( Figs. 6, 7 ). Spermathecae hyaline, collapsed probably due to manipulation or dehydration by ethanol preservation. Fertilisation ducts connected anteriorly to spermathecae, passing through bell-shaped sclerotised capsules and ending in sac-like structures ( Figs. 6, 7 ). Total length 1.8. Carapace 0.7 long, 0.7 wide. Tibia I length 0.42, III 0.42, IV 0.47. Tibia II missing. Abdomen 1.2 long, 0.9 wide.

Variation. Male paratype (IBSP 79530), total length 1.6, carapace width 0.75. Female paratype (MCZ 52195), abdomen with a pair of large cream-coloured lateral spots delimiting a median dark area. Total length 2.1, carapace width 0.8.

Distribution. Known only from two localities in the province of Guanacaste, Costa Rica.

Figures

FIGURES 1–7. Oecobius eberhardi sp.nov. (paratypes, IBSP 79530). 1-4, male left pedipalp: 1, prolateral view; 2, ventral view; 3, retrolateral view; 4, female habitus, dorsal view; 5-7, female epigynum: 5, ventral view (arrow points to the anterior sclerotised plate); 6, internal genitalia, dorsal view (spermatheca and part of fertilization ducts omitted on the left side); 7, hypothesised trajectory of sperm from copulatory openings to the spermatheca (continuous line) and from the spermatheca through the sclerotised capsules and fertilisation ducts (dashed line, ducts omitted). Abbreviations: AH, anterior hood; C, conductor; E, embolus; CA, copulatory atrium; CD, copulatory ducts; FD, fertilisation ducts; OTA, oecobiid tegular apophysis; OTL1, oecobiid tegular lobe 1; S, spermathecae; SC, scletotised capsule; T tegulum. Scale bars: 1–3, 5–6 = 0.1 mm; 4 = 0.5 mm.