Thrandina parocula Maddison, new species

Thrandina parocula Maddison, new species

Figs. 2–8

Type material. Holotype male in UBC­SEM with label: " ECUADOR: MORONA SANTIAGO: 6.6 km N of Limón on highway to Méndez. S 2.9227 W 78.4079; 1000 m el. Forest 14 July 2004 Maddison, Agnarsson, Iturralde, Salazar. WPM#04­041"; "UBC­SEM AR00001"

Paratypes: a second male, a female, and a subadult male, same data as the holotype (UBC­SEM). Molecular data gathered for this species by Maddison & Needham (2006) were obtained from legs of the paratype male (DNA voucher d123).

Etymology. The name refers to the relatively equal sizes of the lateral and posterior eyes.

Diagnosis. The large posterior median eyes (Figs. 5–8) distinguish this from other neotropical salticids, including the described species of Lapsias (Galiano, 1963; types in MNHN examined). The large angled median apophysis of the male palp (Figs. 2–3), and the deep opening of the epigynum (Fig. 4) are also distinctive.

Description. Male holotype: Carapace length 2.3; abdomen length 2.1. Approximate leg lengths 4 = 1> 2 = 3. Macrosetae on tibia I P 1­0­1 V 2­2 ­2, metatarsus I P 0­0­1 V 2­1 ­2 R 0­1­0 (left leg) P 0­1­1 V 2­1 ­2 R 0­0­1 (right leg). Second leg anterior tarsal claw with 5 teeth, posterior with 4–5. Chelicerae: 3 promarginal and 2 retromarginal teeth. Palpus (Figs. 2–3): with a large, distinct median apophysis arising from the membranous area retrolateral of the embolus. The median apophysis expands as it proceeds distally, then angles and sends a spike toward the prolateral, passing behind a short triangular extension of the membrane that may represent the conductor. Colour: carapace dark brown to black except for central pale longitudinal stripe on thorax. Legs pale to medium brown except femur I which is dark brown. Abdomen medium brown above with lighter chevrons; paler below with dark speckles.

Female paratype: Carapace length 1.9; abdomen length 1.7. Macrosetae on tibia I P 1­ 0­0 V 2­1 ­2 (left leg), P 1­0­0 V 2­2 ­2 (right leg), metatarsus I P 0­0­1 V 2­1 ­2. Second leg anterior tarsal claw with 6 teeth, posterior with 5. Chelicerae: 3 promarginal and 2 retromarginal teeth. Palpus: with tarsal claw. Epigynum (Fig. 4): a large mound, with a central opening that descends into a deep cavern. Colour: as in male except that legs are more annulate.

Specimens examined. Subadult males with similar eye arrangement and colouration, and thus presumed to be of this or a closely related species, were found at two other locations: (1) ECUADOR: MORONA SANTIAGO: km 20 from Limón towards Gualaceo. S 3.0044 W 78.5142; 2270 m el. Cloud forest. 11 July 2004 Maddison, Agnarsson, Iturralde, Salazar. WPM#04­029 (UBC­SEM). and (2) ECUADOR: NAPO: Caucheras, Estación Yanayacu. S 0.6049 W 77.8886; 2150 m el. 20 July 2004 Maddison, Agnarsson, Iturralde, Salazar, Avilés. WPM#04­052 (UBC­SEM).

Natural history and behaviour. At the type locality, collected by beating moss­covered branches and tree trunks in the understory of a moist forest near a stream in a narrow canyon at 1000 m elevation. The subadult males from the other two localities were found in similar cloud forest habitats but at higher elevations (2150 m, 2270 m). Walking behaviour of an adult male and subadult male were observed in laboratory conditions for a few minutes. These specimens had a fluid but hesitant walk. Frequently, while pausing in forward motion, they raised and lowered the first and second pairs of legs in synchrony. Their unusual gait is strongly reminiscent of that of spartaeines (W. Maddison, pers. observations; Robert Jackson, pers. comm.).