Sidymella Strand, 1942

Machado, Miguel, Guzati, Catherine, Viecelli, Rafaela, Molina-Gomez, Diana & Augusto Teixeira, Renato, 2019, A taxonomic review of the crab spider genus Sidymella (Araneae, Thomisidae) in the Neotropics, Zoosystematics and Evolution 95 (2), pp. 319-344 : 319

Sidymella Strand, 1942

Sidyma Simon, 1895: 1056. Type species: Stephanopis lucida Keyserling, 1880; by original designation and monotypy; Berland 1913: 95, pl. 9, figs 51-56. Preoccupied by Walker (1856) in Lepidoptera .

Sidymella Strand, 1942: 399 (generic replacement name).

Diagnosis.

Sidymella is similar to Coenypha Simon, 1895 and some species of Stephanopis (e.g. S. antennata , S. ditissima , and S. nodosa ) and these species share a male palp with a long, thin and curled embolus, well-developed pars pendula, and a retrolateral tibial apophysis with a short basal branch (Figs 1A, B, 11 C–F, 13D); the epigynes have a septum formed by the posterior folds of the epigynal plate and long and coiled copulatory ducts (Figs 1C, D, 10 C–F). However, Sidymella species can be recognized and distinguished from these genera by having a bifid opisthosoma (Fig. 1E, F), presence of spiniform macrosetae on the mesial surface of femora I and above the ALE (Fig. 10A, B), the epigyne have a single pair of walnut-shaped spermathecae compartmentalized in several smaller chambers, with accessory glandular heads (Figs 4D, F, 6D, F, 8D, F, 10D, F, 12D, F, 13D, F) while the male palp has a tibial trichobothrium and the RTA have a nodose surface (Fig. 1A, B) unlike other Stephanopinae which present a grooved RTA (with parallel creases on its surface).

Description.

Small spiders (total length 3.00-3.96 in males, 4.68-7.93 in females) with slight sexual size dimorphism, presenting evidence of predominant green colouration in vivo (Fig. 1E, F). Prosoma longer than wide, covered with short and conical setae. Both anterior and posterior eyes disposed in two recurved rows; ALE almost two times larger than the other eyes; ocular macrosetae may be present only above the ALE or on the MOQ area; sternum heart-shaped with concave anterior border, and clypeus with a pair of macrosetae; labium trapezoidal and endites with rounded edges, longer than wide. Opisthosoma with two projections of different sizes, shapes and angles in relation to the opisthosomal axis, varying from rounded and short ones, disposed horizontally/posteriorly, or long, acute and vertically oriented (Figs 2 A–F, 3 A–F). Leg formula: 1 –2–4– 3; anterior tibiae and metatarsi (I and II) ventrally armed with stout macrosetae. Epigynum with membranous and hyaline copulatory ducts, long spermathecae with many chambers or with a single median constriction (Fig. 10D); male palp with RTA rounded or truncated, discoid tegulum and ribbon-like embolus and (Fig. 10 C–F).

Composition.

Six Neotropical species: Sidymella excavata sp. nov., S. furcillata (Keyserling, 1880), S. longispina ( Mello-Leitão, 1943), S. lucida (Keyserling, 1880), S. marmorata sp. nov., and S. kolpogaster (Lise, 1973); 11 additional species from the Australasian region that are not within the scope of the present study.

Distribution.

Ecuador, Colombia, Peru, Brazil, Argentina, and Uruguay (Fig. 15).