Stygnus simplex ( Roewer, 1913 )

Villarreal, Osvaldo, Ahumada-C, Daniela & Flórez, Eduardo, 2024, A glimpse into the diversity of Stygnus Perty, 1833: A new Colombian species and additional records from South America (Opiliones, Stygnidae), European Journal of Taxonomy 970, pp. 203-229 : 216-218

Stygnus simplex ( Roewer, 1913)

Figs 8A–D , 9A–B

Material examined (assigned tentatively)

COLOMBIA – Vaupés (new department record) • 1 ♂; Lago Taraira, Estación Biológica Mosiro Itájura Caparú ; 1°04′ S, 69°30′ W; alt. 200 m; 2002–2004; J. Pinzón leg.; ICN-Ao 1889 . • 1 ♂; Taraira, Estación Biológica Caparú ; 1°04′ S, 69°30′ W; alt. 200 m; 24 Apr. 2013; L. Benavides leg.; ICN-Ao 340 .

Remarks

The specimens studied here exhibit slight differences from the original description, particularly in the ornamentation of femur IV, with a row of larger retrolateral tubercles and the presence of an additional large tubercle on the distal prolateral area of the patella ( Fig. 9 ). Additionally, the male genitals show some notable variations in style+gland size in relation to the LP and the position of the MSC in the LP. These variations were compared with the description provided by Pinto-da-Rocha (1997). It’s important to note that Roewer’s description did not include an examination of the genitalia. However, our examination of the male genitalia revealed these important differences. Despite these variations, due to the overall morphological similarities between our specimens and those described in literature, as well as the geographical distance between the populations studied and the limited number of specimens evaluated, we tentatively assigned our specimens to S. simplex . Nevertheless, we acknowledge the necessity of further investigation, including the study of larger samples or methodologies such as molecular analysis to confirm this assignment.

Distribution

Ecuador: Napo ( Roewer 1913); Colombia: Putumayo ( Kury 2003) and Vaupés; Peru: Loreto.

Figures

Fig. 8. Stygnus simplex (ICN-Ao 1889). A. Habitus, panoramic dorsal view. B. Detail of dorsal scutum and chelicerae. C. Panoramic lateral view. D. Detail of the body, lateral view. Scale bars = 1 mm.

Fig. 9. Stygnus simplex (ICN-Ao-1889), left leg IV. A. Retrolateral view. B. Prolateral view. Scale bars = 1 mm.