Synemosyna aurantiaca

Synemosyna aurantiaca (Mello-Leitão, 1917)

Figs 3A, D, 4A, D, 6A–D

Simonella aurantiaca Mello-Leitão, 1917: 138.

Simonella mastigostyla Mello-Leitão, 1917: 140, fig. 2.

Simonella claustrorum Mello-Leitão, 1933: 62, pl. 1 fig. 6.

Simonella ypsilon Piza, 1937: 311, pl. 1 figs 3–4, pl. 2 fig. 5.

Simonella aurantiaca – Mello-Leitão 1933: 58, pl. 1 fig. 2.

Simonella mastigostyla – Mello-Leitão 1933: 59, pl. 1 fig. 4, pl. 2 fig. 8.

Synemosyna aurantiaca – Galiano 1966: 348, figs 8–11, 44–46, 49, 61. — Cutler & Müller 1991: 174, figs 13–15.

Type deposit

The types of S. aurantiaca and its synonyms were destroyed in a recent fire (World Spider Catalog 2020; A. Kury, unpublished).

Diagnosis

Tibial apophysis of male palp triangular, shark fin-like and laterally flattened; bulb narrowing distally, 1.2 times longer than wide; embolus originating prolaterally, curling around retrodistal end of cymbium, bending back sharply along dorsal cymbial surface towards base, before bending back near retrolateral edge to tip; anterior margin of epigynal atrium slightly procurved; copulatory openings located posteromedially, copulatory ducts loop anteriorly back to level of spermathecae, entering kidney-shaped spermathecae anterolaterally.

Material examined

BOLIVIA – Santa Cruz Dept • 2 ♂♂; Bermejo; 18.136º S, 63.631º W; 13 Jan. 2016; R. Perger leg.; IBSI-Ara 0735 • 4 ♂♂, 8 ♀♀, 1 imm.; Cotoca; 17.7736° S, 63.065° W; 11 Jul. 2018; R. Perger leg.; CBF • 2 ♂♂, 3 ♀♀; Santa Rosa de la Mina; 16.5391° S, 62.4622° W; 9–13 Sep. 2016; R. Perger leg.; CBF. – Chuquisaca Dept • 1 ♂, 2 ♀♀; Teja Huasi; 18.9475° S, 65.1369° W; 18 Dec. 2017; R. Perger leg.; CBF. – Tarija Dept • 1 ♂, 4 ♀♀; Arambulo; 21.809º S, 64.232º W; 9 Jan. 2016; R. Perger leg.; IBSI-Ara 0773 • 4 ♂♂, 5 ♀♀; same collection data as for preceding; CBF.

ARGENTINA – Misiones Province • 1 ♀; General Manuel Belgrano Dept, San Antonio; 26.019º S, 53.791º W; 11 Nov. 2011; G.D. Rubio leg.; IBSI-Ara 0182 • 1 ♀; Karadya Bio-Reserve; 25.859º S, 53.961º W; 7 Apr. 2016; J.E. Baigorria leg.; IBSI-Ara 0612 • 1 ♂; same collection data as for preceding; 15 Sep. 2016; IBSI-Ara 0783 • 1 ♂; Bernardo de Irigoyen; 26.247º S, 53.639º W; 31 Oct. 2016; G.D. Rubio leg.; IBSI-Ara 0867.

Comparisons

The triangular, shark fin-like tibial apophysis and the embolus without complete revolution are also found in S. decepiens (O. Pickard-Cambridge, 1896) (Mexico, Guatemala) (Cutler 1985). However, in the latter, the bulb broadens distally and is 1.5 times longer than wide. In S. invemar Cutler & Müller, 1991 (Colombia), the spermathecae are kidney-shaped but the tubes do not loop back to the level of the spermathecae and enter the spermathecae posteriorly (Cutler & Müller 1991).

Variation

The following forms were collected in sympatry in all locations: orange-reddish, light brown, and dark brown to blackish forms (Fig. 6A–D). All orange-reddish forms were smaller than 5.55 mm (n = 9) and all dark-brown to blackish variants longer than 5.8 mm (n = 8), indicating an ontogenetic change in body color with light brown transitional forms. There was no apparent sex-related difference in body color.

Geographical and ecoregion distribution (Fig. 7)

This species has been recorded from Brazil (Galiano 1966; Raizer 2004; Podgaiski et al. 2007; Rodrigues et al. 2009, 2016), Uruguay (Laborda Turrión 2016), Argentina (Galiano 1966; Zapata & Grismado 2015) and Bolivia (present study). Cutler & Edwards (2002) recorded S. aurantiaca from Trinidad Island (Lesser Antilles). The taxonomic status of these specimens remains to be determined. Synemosyna aurantiaca is distributed in mostly semi-deciduous forests south of 18° (Fig. 7). According to the biogeographic regionalization of Olson et al. (2011), previous records refer to the following ecoregions: Pantanal, Humid Pampas, Parana flooded Savanna, Uruguayan Savanna, Alto Paraná Atlantic forest, Serra do Mar coastal forests and Araucaria moist forest. In the present study, S. aurantiaca was sampled in Inter-Andean Bolivian Tucuman dry forest (Teja Huasi), Bolivian Tucuman forests (Arambulo), and subhumid, semi-deciduous Chiquitano forest (Bermejo, Cotoca, Santa Rosa de la Mina, Santiago de Chiquitos).

Remarks

Galiano (1966) collected co-occurring yellow/orange and dark forms in Paraná de las Palmas and Canal 6, Buenos Aires province, Argentina. Oliveira (1988) reported similar forms from Brazil. Both authors mentioned that the species lacks sexual dichromatism, which is supported by the observations in the present study.

Previous records of this species referred to a comparably narrow range in southeast Brazil and northeast Argentina. Synemosyna aurantiaca is reported here for the first time from Bolivia. Teja Huasi (Chuquisaca Dept), located at an elevation of 2000 m a.s.l., is the highest reported elevation for any species of the tribe Simonellini. The record from Bermejo (Santa Cruz Dept) is the northern- and westernmost record of this species, extending the distributional range more than 900 km to the northwest of the previously reported northernmost location in Mato Grosso do Sul (Fazenda São Bento, Brazil).

The record from Colombia (Cutler & Müller 1991) likely refers to another species, as the illustrated female does not only have a different epigyne (as already stated by Cutler & Müller 1991), but also pear-shaped spermathecae (kidney-shaped in S. aurantiaca); a bipartite dorsal scutum on the anterior half of the abdomen (one entire scutum in S. aurantiaca); a narrower carapace, resulting in a ratio length/width of 2.7 (~ 2.1 in S. aurantiaca), with concave lateral borders (convex in S. aurantiaca), and the middle part as narrow as the distance between the last posterior eyes (broader in S. aurantiaca).