Grammostola diminuta, Ferretti & Pompozzi & González & Pérez-Miles, 2013

Ferretti, Nelson, Pompozzi, Gabriel, González, Alda & Pérez-Miles, Fernando, 2013, The genus Grammostola Simon 1892 (Araneae: Theraphosidae): a new species from western Argentina, new synonymy and distributional data, Journal of Natural History 47 (47 - 48), pp. 2961-2977 : 2963-2966

Grammostola diminuta sp. nov.

( Figures 1 , 2 , Tables 1, 2)

Type material

Holotype: male: ARGENTINA: Ascha, Aimogasta, La Rioja, Julián Caceres Freyre leg., March 1947 (MACN-Ar 30311) . Paratype female: ARGENTINA: Aimogasta, La Rioja, Julián Caceres leg., 29 April 1945 (MACN-Ar 30312) .

Other material examined

ARGENTINA: Catamarca Province: 1 ♀, Catamarca, 11 December 1943, no collector data (MACN-Ar 30316) ; 1 ♀, same locality, 11 December 1943, no collector data (MACN-Ar 30316) ; 1 ♂, same locality, 1946, Schaefer leg., (MACN-Ar 30317) . Chaco Province: 1 ♂ , 1949, Cramwell leg. (MACN-Ar 2837); 1 ♂, 1949, Cramwell leg. (MACN-Ar 2837); 1 ♂, 1949, Cranwell leg. (MACN-Ar 2837). La Rioja Province: 1 ♂ , Ascha, Aimogasta , March 1947, Julian Cáceres Freyre leg. (MACN-Ar 2208) ; 2 ♂, same locality, 1949, J. Cramwell leg. (MACN-Ar 30315) ; 2 ♂, Aimogasta , 29 September 1945, Julian Cáceres Freyre leg. (MACN-Ar 30313) ; 1 ♂, Finca Ascha, Sierra Velasco, Aimogasta, no date, Julian Cáceres Freyre legs. (MACN-Ar 30314). Mendoza Province : 1 ♂, Ñacuñan , 12 September 1975, Arturo Roig Alsina leg. (MACN-Ar 30318) .

Etymology

The specific epithet is an adjective that in Spanish means “very small”, considering that this is the smallest known species of Grammostola .

Diagnosis

This species differs from other species of Grammostola by its small size, about 25 mm of body length (excluding chelicerae and spinnerets). Males can be recognized from all Grammostola species by a small bristle of erected and stiff setae at the palpal tarsi ( Figure 1G ). Additionally, it differs from G. burzaquensis by the absence of the smooth setae on the prolateral and retrolateral aspects of legs and retrolateral palpal maxillae, and by the presence of curved spermathecal receptacles ( Ferretti et al. 2011). It can be distinguished from G. vachoni by its small size, the shape of the palpal bulb and the absence of the stiff spiniform setae on the prolateral and retrolateral aspects of legs and retrolateral palpal maxillae. It differs from G. inermis Mello-Leitão, 1941 by its small size, the shape of the palpal bulb and the shape of the spermathecae with curved receptacles ( Schiapelli and Gerschman 1961).

Description

Male holotype: colour (in alcohol): carapace and legs light brown, abdomen dark brown. Total length, not including chelicerae or spinnerets 23.7. Cephalothorax 11.1 long, 10.6 wide. Anterior eyes row procurved, posterior row recurved. Eye sizes and inter-distances: AME 0.22, ALE 0.28, PME 0.15, PLE 0.20, AME–AME 0.37, AME–ALE 0.15, PME–PME 0.70, PME–PLE 0.05, ALE– PLE 0.16. Eye tubercle: length 1.1, width 1.5; clypeus 0.6. Fovea: deep straight, 2.0 long. Labium: length 1.5, width 1.8, with approximately 104 cuspules, although cuticular holes indicate 116 originally. Maxillae: each with approximately 127 cuspules spread over internal face. Sternum: length 5.1, width 4.7 ( Figure 1D ).

Chelicerae with seven large teeth on promargin and three small teeth on retromargin. Long spiniform setae on prolateral, retrolateral coxal faces of legs I–IV, retrolateral palpal maxillae ( Figure 1E, F ). Tarsi I–IV fully scopulate. Metatarsi I scopulate on three-quarters, metatarsi II scopulate on apical half, metatarsi III scopulate on one-third, metatarsi IV scopulate on apical quarter. Urticating hair types III and IV present.

Spination. Femora and Patellae of I–IV and palp, 0. Tibiae: palp 1-2-1-2 P, 1 V; I 1-1-2-2 P, 1–1 R, 2 V; II 1-1-1 P, 1–1 R, 1-2-1 V; III 1-1-1-1 P, 1–1 R, 2–1 V; IV 1-1-1 P, 1–1 R, 1 V. Metatarsi: I 1-1-1 V, 1 R; II 1–1 P, 1 R, 1–1 V; III 1-2-1-1 P, 1–2 R, 1–1 V; IV 1-1-1-1-1-1 R, 1-1-1-1 P, 1-1-1 V. Tarsi I–IV, palps 0.

Tibia I with ventral apophysis, the PB bearing a long stiff black thorn on inner side, slightly curved at tip and longer than the spur, RB with a long spine subapically ( Figure 1A ). Length of legs and palpal segments in Table 1. Male palpal bulb pyriform with PI and PS developed, curved and long embolus, bent at the mid-portion ( Figure 1B, C ).

Female paratype: colour (in alcohol): same as in male. Total length, not including chelicerae or spinnerets 27.9. Cephalothorax 13.3 long, 12.4 wide. Anterior eyes row procurved, posterior row recurved. Eye sizes and inter-distances: AME 0.39, ALE 0.33, PME 0.23, PLE 0.22, AME–AME 0.35, AME–ALE 0.23, PME–PME 0.90, PME–PLE 0.07, ALE– PLE 0.08. Eye tubercle: length 1.4, width 1.8; clypeus 0.8. Fovea: deep straight, 2.0 long. Labium: length 2.0, width 2.5, with approximately 114 extant cuspules, although cuticular holes indicate 123 originally. Maxillae: each with approximately 140 cuspules spread over internal face. Sternum: length 5.0, width 4.7.

Chelicerae with five large teeth on promargin. Long spiniform setae on prolateral and retrolateral coxal faces of legs I–IV and retrolateral palpal maxillae. Tarsi I–IV fully scopulate, tarsus III divided by a row of one setae, tarsus IV divided by row of three setae. Metatarsi I fully scopulate, metatarsi II scopulate on three-quarters, metatarsi III scopulate on apical half, metatarsi scopulate on two-thirds. Length of legs and palpal segments in Table 2. Urticating hair types III and IV present.

Spination. Femora and patellae of I–IV and palp, 0. Tibiae: palp 2-1-1 P; I 1 V; II 1–1 V; III 1 R, 1–1 P, 1–1 V; IV 1 R, 1 P, 1 V. Metatarsi: I 1–1 V; II 1–1 R, 1 V; III 1–1 R, 1 V, 1–2 P; IV 1-2-1 R, 2-1-2 P, 1-1-1 V. Tarsi I–IV and palps 0. Two curved spermathecal receptacles ( Figure 1H ).

Variation

Twelve males: total length 22.6–28.2 (24.85 ± 1.37); cephalothorax length 10.1–12.5 (11.73 ± 0.71); cephalothorax width 9–11.1 (10.43 ± 0.63). Three females: total length 21.3–27.9 (24.5 ± 3.30); cephalothorax length 9.2–13.3 (10.97 ± 2.11); cephalothorax width 8.4–12.4 (9.8 ± 2.25).

Remarks

The size of Grammostola species from Argentina ranged from the small G. burzaquensis Ibarra-Grasso 1946 (about 32 mm of total length) to G. pulchripes (about 80 mm in total length), thus G. diminuta sp. nov. is the smallest species known of the genus.

Distribution

Western Argentina along the eastern Andes (Mendoza, La Rioja and Catamarca Provinces). Also, G. diminuta is present in north-central Argentina (Chaco Province) ( Figure 2 ) .

Figures

Figure 1. Grammostola diminuta sp. nov., male (A–G). (A) Tibial apophysis; (B) palpal bulb, retrolateral; (C) palpal bulb, prolateral; (D) sternum, ventral view; (E) prolateral face of coxa I; (F) prolateral face of coxa I, close up to the stridulatory setae; (G) palp, prolateral view. Grammostola diminuta sp. nov., female. (H) Spermathecae, dorsal view. PS = prolateral superior keel, PI = prolateral inferior keel. Scale bars = 1 mm.

Figure 2. Distribution map of Grammostola diminuta sp. nov.