Trechalea tirimbina, Cruz, Estevam L., Silva, Da & Lapinski, Witold, 2012

Cruz, Estevam L., Silva, Da & Lapinski, Witold, 2012, A new species of Trechalea Thorell, 1869 (Araneae: Lycosoidea: Trechaleidae: Trechaleinae) from Costa Rica, with notes on its natural history and ecology, Zootaxa 3563, pp. 58-64 : 59-63

Trechalea tirimbina new species

Figs 1–19

Trechalea sp.; Lapinski & Tschapka, 2009: 6.

Types. Male holotype from Reserva Biológica Tirimbina , Heredia Province, Costa Rica [10°24'N, 84°07'W], IV- VII.2008, W. Lapinski (MCTP 33749). Paratype: one female, same locality and data as the holotype (MCTP 33750).

Etymology. The specific name is a noun in apposition, taken from the type locality.

Diagnosis. The male palpus of Trechalea tirimbina sp. nov. resembles that of Trechalea extensa O. Pickard- Cambridge, 1896 (see Carico 1993: 241, fig. 20) by the presence of a tooth-like projection on the dorsal division of the median apophysis (DD) ( Fig. 7 ), character also shared with Trechalea longitarsis (C. L. Koch, 1847) (see Carico, 1993: 241, fig. 15), but can be distinguished by the short tip of the guide (G) on the terminal apex of the dorsal division of the median apophysis (DD) ( Fig. 7 ) and by the larger ectal division of the retrolateral tibial apophysis (ECD) ( Figs 12, 13 ). The female is similar to those of T. extensa (see Carico 1993: 248, fig. 55) by the projected scape-like middle field of epigynum (MF), but can be distinguished by the narrower tip of the scape ( Figs 16, 17 ) and by the shorter and rounded head of spermathecae (HS) ( Figs 18, 19 ).

Description. Male (Holotype, Heredia Province, Costa Rica, MCTP 33749). Total length 21.94. Carapace 10.64 long, 10.37 wide, light brown with a median irregular light brown band; laterals dark brown with short dark brown bristles; fovea marked ( Fig. 3 ). Clypeus dark brown, 1.24 high. Anterior eye row recurved, 2.01 wide; posterior recurved 3.65 wide. Eye diameters: AME 0.46, ALE 0.31, PME 0.83, PLE 0.77; interdistances: AME-AME 0.31, AME-ALE 0.12, PME-PME 0.43, PME-PLE 0.74; median ocular quadrangle: OQA 1.17, OQP 1.79, OQH 1.67. Chelicerae dark brown, frontal face bristly; promargin and retromargin of fang furrow with three teeth equidistant and equal in size. Sternum yellow, light brown laterally, bristly; 5.58 long, 5.05 wide. Labium dark brown, 1.86 long, 1.99 wide. Legs light brown with a dark brown irregular patches, relative length: IV–II–I–III, I—femur 17.82/ tibia-patella 19.15/ metatarsus 19.55/ tarsus 12.10/ total 68.62; II—20.08/ 20.74/ 21.81/ 12.90/ 75.53; III—16.35/ 19.10/ 16.22/ 10.64/ 62.31; IV—21.14/ 26.06/ 25.93/ 15.29/ 88.42. Ventral pairs of macrosetae on tibiae: I–4; II–4; III–3; IV–3. Superior tarsal claw with seven teeth ( Fig. 14 ). Abdomen, 10.90 long, dorsum dark gray, bristly and with three pairs of sigillae ( Fig. 3 ). Venter light brown, scattered bristles. Ventral division of the median apophysis (VD) of the male palpus with an acute apex ( Figs 6, 7 ). Dorsal division of the median apophysis (DD) with a distal tooth-like projection ( Figs 7 , 10 ) and short guide (G) ( Figs 7 , 10 ). Retrolateral tibial apophysis (RTA) prominent ( Fig. 8 ). Ental division of RTA ( END) short and retrolaterally curved ( Fig. 11 ). Ectal division (ECD) of RTA with a lamellar projection, dorsally grooved ( Figs 12, 13 ).

Female (Paratype, same locality as holotype, MCTP 33750). Total length 25.27. Carapace 10.37 long, 10.39 wide, colour as in male ( Fig. 4 ). Clypeus dark brown, 1.24 high. Anterior eye row straight, 1.95 wide; posterior recurved 3.73 wide. Eye diameters: AME 0.27, ALE 0.31, PME 0.77, PLE 0.62; interdistances: AME-AME 0.27, AME-ALE 0.15, PME-PME 0.40, PME-PLE 0.71; median ocular quadrangle: OQA 1.08, OQP 1.82, OQH 1.67. Chelicerae colour and shape as in male. Sternum yellow, bristly; 5.98 long, 5.05 wide. Labium dark brown, 1.72 long, 1.99 wide. Legs, colour as in male, relative length: IV–II–I–III, I—femur 17.95/ tibia-patella 17.29/ metatarsus 16.75/ tarsus 11.30/ total 63.24; II—18.35/ 24.33/ 18.62/ 12.63/ 73.93; III—14.89/ 17.42/ 15.69/ 10.37/ 58.37; IV—19.41/ 23.94/ 23.27/ 14.89/ 81.51. Ventral pairs of macrosetae on tibiae: I–4; II–4; III–3; IV–3. Female palpal claw with seven teeth ( Fig. 15 ). Abdomen, 15.69 long, colour and shape as in male ( Fig. 4 ). Female epigynum with a projected scape-like middle field (MF) ( Figs 16, 17 ). Head of spermathecae (HS) short and rounded with pores ( Fig. 19 ) and with a circular accessory spermathecae ( AS) ( Fig. 18 ). Copulatory ducts (CD) short and wide ( Fig. 18 ).

Other material examined. COSTA RICA, Heredia Province: Tirimbina Biological Reserve [10°24'N, 84°07'W], 2 3, 2 Ƥ, IV-VII.2008, W. Lapinski ( MCTP 33751, 33752, 33753, 33754); Limón Province: Matama, Fila Asunción [09°54'N, 83°09'W], elevation 400m, 1 Ƥ, 02.VII.2003, M. Aguirre ( INBio 74274), Cental, Valle de La Estrella, Reserva Biol Hitoy Cerere, Est Hitoy Cerere, La Poza de las Chichis [09°40'N, 83°01'W], elevation 120m, 1 3, 25.VI.1998, E. Rojas ( INBio 75115).

Distribution. Costa Rica (Limón and Heredia Provinces) ( Fig. 1 ).

Natural history and ecology. Like other Trechalea species ( Carico 1993), T. tirimbina sp. nov. was found along forest creeks and small rivers ( Fig. 2 ). Most specimens were found at night on objects like logs, stones and boulders in the middle and along the banks of the creeks. Some individuals could be found during the day on the underside of logs. The typical hunting posture was the spiders attached with legs III and IV to the substrate and legs I and II touching the water surface ( Fig. 4 ). Many spiders were found on vertical objects not touching the water and some spiders were hanging from objects above water with the front legs in the air (Lapinski, pers. obs.). In a few occasions the prey of T. tirimbina sp. nov. could be identified. The spiders consumed crickets ( Gryllidae ) and smaller spiders from diferent families (Lapinski, unpubl. data). The males of T. tirimbina sp. nov. captured small crickets and a small spider and used them as nuptial gifts during courtship ( Lapinski & Tschapka 2009; Lapinski, unpubl. data). This behaviour has also been observed in T. amazonica from Northern Brazil ( Silva & Lise 2009). Based on observations on individually marked spiders, the species appears to have high site fidelity (Lapinski, unpubl. data). Females carry the flat bluish gray egg sac attached to the spinnerets and the newly hatched spiderlings stay for approximately two to three days on the abdomen and the egg sac, which remains attached to the spinnerets (Lapinski, pers. obs., Fig. 5 ).

Figures

FIGURE 1. Known distribution of Trechalea tirimbina sp. nov. in Costa Rica.

FIGURES 2 – 5. Trechalea tirimbina sp. nov. (2 Tirimbina river at “ Reserva Biológica Tirimbina ”, north-eastern Costa Rica, 3 male, 4 female on hunting posture, 5 female with egg sac and spiderlings). Photos: W. Lapinski.

FIGURES 6 – 9. Trechalea tirimbina sp. nov., male palpus (6, 7, ventral, 8, 9 retrolateral). (DD = dorsal division of MA, E = embolus, ECD = ectal division of RTA, END = ental division of RTA, G = guide (terminal end of MA), MA = median apophysis, RTA = retrolateral tibial apophysis, ST = subtegulum, T = tegulum, VD = ventral division of MA).

FIGURES 10 – 15. Trechalea tirimbina sp. nov., male palpus (10 ventral, detail of median apophysis, 11 retrolateral tibial apophysis, ventral, 12 ectal division of RTA, retrolateral 13 detail of ECD, retrolateral 14 tarsal claw of right leg II, lateral 15 female left palpal claw, lateral). (DD = dorsal division of MA, E = embolus, ECD = ectal division of RTA, END = ental division of RTA, G = guide (terminal end of MA), MA = median apophysis, RTA = retrolateral tibial apophysis, T = tegulum, VD = ventral division of MA).

FIGURES 16 – 19. Trechalea tirimbina sp. nov., female epigynum (16, 17, ventral, 17 detail of middle field, 18, 19 dorsal, 19 detail of the head of spermathecae). (AS = accessory spermathecae, CD = copulatory duct, FD = fertilization duct, HS = head of spermathecae, LL = lateral lobes, MF = middle field of epigynum).