Synemosyna nicaraguaensis Cutler, 1993

Perger, Robert, Rubio, Gonzalo D. & Haddad, Charles R., 2021, On ant-like Synemosyna Hentz, 1846 spiders from Bolivia, with indirect evidence for polymorphic mimicry complexes (Araneae: Salticidae: Simonellini), European Journal of Taxonomy 748 (1), pp. 67-88 : 76-80

Synemosyna nicaraguaensis Cutler, 1993

Figs 3C, F , 4C, F , 5C–F , 9A–D

Synemosyna nicaraguaensis Cutler, 1993: 2 , figs 1–2.

Type deposit

Holotype ♀ in MEL (examined).

Diagnosis

Bulb small (60% of cymbium length) ( Fig. 5F ); tibial apophysis bifurcate, ventral lobe larger; epigyne with complete, sclerotized transverse hood with strongly procurved anterior margin; female spermathecae large (width of each 35–45% of maximum width of epigyne between sclerotized rims), pear-shaped, and accessory glands as long as spermatheca diameter ( Fig. 5D ).

Material examined

Holotype

NICARAGUA – ♀; Río San Juan, El Castillo [El Castillo de Concepción, 11°01′ N, 84°25′ W]; 30 Jul. 1989; F. Reinboldt leg.; MEL.

Other material

BOLIVIA – Santa Cruz Dept • 25 ♂♂, 37 ♀♀; La Guardia ; 17.883º S, 63.317º W; Sep. 2015 – Aug. 2017; R. Perger leg.; CBF • • 2 ♂♂, 2 ♀♀; same collection data as for preceding; IBSI-Ara 0724 • 1 ♀; Buena Vista ; 17.465º S, 63.696º W; 21 Jan. 2016; R. Perger leg.; IBSI-Ara 0725 • 2 ♀♀; same collection data as for preceding; CBF • 5 ♂♂, 8 ♀♀; Santa María La Antigua ; 17.3719° S, 63.6563° W; 10–11 Apr. 2018; R. Perger leg.; CBF . – La Paz Dept • 2 ♂♂, 6 ♀♀; Villa Teresa ; 16.201º S, 67.829º W; 17 Jan. 2018; R. Perger leg.; IBSI-Ara 1023 • 3 ♂♂, 8 ♀♀; same collection data as for preceding; 16–18 Jan. 2018; R. Perger leg.; CBF .

Comparisons

The bifurcated tibial apophysis is only shared with S. maddisoni Cutler, 1985 and S. paraensis Galiano, 1967 . However, both species can be separated from S. nicaraguaensis by a larger bulb (65% of cymbium length in S. maddisoni and 80% in S. paraensis ) and the different size and shape of the lobes of the retrolateral tibial apophysis (cf. Fig. 5F with Chamé-Vázquez et al. 2020: figs 14–15). The female habitus ( Fig. 4C ) and the almost round spermathecae ( Fig. 5D ) are shared with the female of S. maddisoni . Females of S. maddisoni can be distinguished from those of S. nicaraguaensis by an epigyne with a U-shaped flap, which is wide and short in S. nicaraguaensis (compare Fig. 5C with Chamé-Vázquez et al. 2020: fig. 11).

The habitus of females of S. nicaraguaensis resembles that of S. hentzi Peckham & Peckham, 1892 ( Peckham & Peckham 1892: pl. 7 fig. 2). Synemosyna hentzi was described very briefly based on a single female that was collected in Chapada dos Guimarães, close to Cuiabá, Mato Grosso state, Brazil, and maintained in the Herbert H. Smith collection ( Peckham & Peckham 1892), but the type specimen appears to be lost ( Galiano 1971). No description or illustration of the genitalia was provided, and no further specimens of this species were recorded in subsequent works. Considering the original description ( Peckham & Peckham 1892), S. hentzi differs from S. nicaraguaensis by a broader, less elongated carapace, 2 times longer than wide (2.5 in S. nicaraguaensis ), with the lateral borders parallel (with a slightly narrower constriction in S. nicaraguaensis ) and without a dorsal constriction (present in S. nicaraguaensis ), the AER only slightly curved (strongly in S. nicaraguaensis ), and the ALE and AME touching each other (separated in S. nicaraguaensis ).

Description

Male (IBSI-Ara 0724)

Total BL: 4.60. Carapace length 2.05; width: 0.81. Integument smooth, shiny, with simple, separate white setae, denser and longer on cephalic area (particularly around AME), posterior constriction of thoracic area, and on transverse area of anterior part of abdomen. Carapace slender and elongated, cephalic portion slightly longer than wide, followed by slightly narrower constriction, slight impression behind cephalic area (resembling anterior pronotal margin); dense white scales posterolateral of cephalic area, thoracic part about as long as cephalic part, of same width, globose, posteriorly constricted, constriction concave in lateral view. Row of AME and ALE recurved, AME touching each other, separated from ALE, ALE at anterior edges of cephalic area, rectangle of ALE and PE 1.5 times as wide as long. Chelicerae with 2 promarginal and 5 retromarginal teeth. Sternum dark brown. Coxae and trochanters translucent whitish; legs relatively long, 4312; femora stout, remaining segments slender, femora I–III translucent yellowish, I and III somewhat darker distally, IV proximally and distally as in anterior part of abdomen, central half translucent yellowish; tibia I simple, with moderately long setae.

Abdomen length: 2.50; width: 0.70, proximal half broadening in distal direction in dorsal view, proximal and distal half of abdomen separated by concave constriction, distal part of abdomen acuminate oval. Dorsal scutum almost extending along the whole length of abdomen, rectangular proximally, merging into disc-shaped, heavily sclerotized plate on distal half of anterior abdominal part, proximal part of plate surrounded by band of short white setae; scutum narrowing at level of abdominal constriction and widening again on distal half of abdomen, terminating shortly before abdominal apex; epigastric scutum folded over dorsolateral border of anterior part of abdomen, covering somewhat lateral sides of scutum.

Bulb about 60% of the cymbium length, ovoid, narrowing proximally, tibial apophysis bifurcate, ventral tooth larger; embolus thin, arising from the basal side of the bulb, without complete circular revolution, angular, surrounding bulb prolaterally towards the apical cymbial groove.

Variation

Four different color morphs were observed in males ( Fig. 9B–D , Table 1 ), with no apparent ontogenetic change in body color. The forms included orange-reddish, completely light brown or dark brown forms (all locations), and variants with dark orange carapace and black abdomen (La Guardia and Villa Teresa). In a sample of 51 females, 92% were orange with a pair of black spots on the posterior half of the abdomen ( Fig. 9A ), and 8% dark brown. Orange males with dark spots on their abdomen were not observed. The comparably even distribution of color forms among males, the high number of orange females, and the lack of orange forms with black abdominal spots in males indicate sex-specific polychromatism.

Geographical and ecoregion distribution ( Fig. 7 )

Synemosyna nicaraguaensis is known from Nicaragua (type location) and Bolivia (present study). In Bolivia, it was collected in the following forest types: Bolivian Yungas forest (Villa Teresa), Sub-Andean Southwest Amazon moist forest (Buena Vista), and Sub-Andean subhumid semi-deciduous Chiquitano forest (La Guardia, Santa María la Antigua).

Remarks

The localities in Nicaragua and Bolivia are more than 3500 km apart, which is remarkable for such a small arthropod, and would suggest a certain degree of reproductive isolation between both populations. However, the epigyne (examined from drawings by Cutler 1993) and external morphology (examined from photographs of the type) are similar in the type specimen of S. nicaraguaensis and the Bolivian material. Another species with a wide distributional range, S. americana , occurs from Mexico to Venezuela ( Cutler 1981b). The other two Bolivian species of Synemosyna have also comparably wide distribution ranges ( Fig. 7 ). The widest collection locations of S. aurantiaca are about 2200 km apart, and of S. myrmeciaeformis about 3100 km. Molecular studies are needed to test whether the low grade of morphological differentiation in these species represents a high gene flow.

Figures

Fig. 3. Dorsal and lateral habitus, males (all CBF). A, D. Synemosyna aurantiaca (Mello-Leitão, 1917). B, E. S. myrmeciaeformis (Taczanowski, 1871). C, F. S. nicaraguaensis Cutler, 1993. Scale bars = 1 mm.

Fig. 4. Dorsal and lateral habitus, females (all CBF). A, D. Synemosyna aurantiaca (Mello-Leitão, 1917). B, E. S. myrmeciaeformis (Taczanowski, 1871). C, F. S. nicaraguaensis Cutler, 1993. Scale bars = 1 mm.

Fig. 5. Genitalia of Synemosyna spp. A–B. S. myrmeciaeformis (Taczanowski, 1871). A. Epigyne. B. Spermatheca and copulatory duct. C–F. S. nicaraguaensis Cutler, 1993. C. Epigyne. D. Spermatheca and copulatory duct. E. Palp, retrolateral view. F. Idem, ventral view.

Fig. 9. A–D. Color variants and potential ant models for Synemosyna nicaraguaensis Cutler, 1993. A. Orange female, La Guardia, Santa Cruz Dept. B. Orange male, same location. C. Orange/black male, same location. D. Dark brown male, Villa Teresa, La Paz Dept.E. Pseudomyrmex simplex (Smith, 1877). F. P. cf. pallidus (Smith, 1855). G. Pseudomyrmex sp. H. P. filiformis (Fabricius, 1804). I. P. peruvianus (Wheeler, 1925). J. P. elongatus (Mayr, 1870). K. P. triplarinus (Weddell, 1850).

Fig. 7. Ecoregion distribution of Synemosyna spp. Orange circle = S. nicaraguaensis Cutler, 1993; red star = S. myrmeciaeformis (Taczanowski, 1871); blue diamond = S. aurantiaca (Mello-Leitão, 1917).