Epicadinus trispinosus ( Taczanowski, 1872 )

Prado, André Wanderley Do, Baptista, Renner Luiz Cerqueira & Machado, Miguel, 2018, Taxonomic review of Epicadinus Simon, 1895 (Araneae: Thomisidae), Zootaxa 4459 (2), pp. 201-234 : 212-217

Epicadinus trispinosus ( Taczanowski, 1872)

Figs 5–7 , 15

Thomisus cornutus Taczanowski, 1872: 88 , pl. 4, fig. 8. New synonymy.

Thomisus trispinosus Taczanowski, 1872: 99 .

Stephanopis cornuta (Taczanowski) . Keyserling 1880: 183, pl. 4, fig. 100.

Stephanopis trispinosus (Taczanowski) . Keyserling 1880: 184, pl. 4, fig. 101.

Eripus trifidus O. Pickard-Cambridge, 1893: 121 , pl. 15, fig. 12. New synonymy.

Epicadinus trifidus (O. Pickard-Cambridge) . Simon 1895: 1052; F. O. Pickard-Cambridge 1900: 159, pl. 10, fig. 33.

Epicadinus trispinosus (Taczanowski) . Simon 1895: 1052; Mello-Leitão 1929: 99 (in part).; Machado et al. 2017: 454, figs S8A, S10D.

Tobias cornutus (Taczanowski) . Simon 1895: 1053.

Epicadinus cornutus (Taczanowski) . Mello-Leitão 1929: 105.

Type-material: Holotype of Epicadinus cornutus : female, FRENCH GUIANA, Cayenne , 1868–1871, C. Jelski (MIZ 500 0 0 1, Figs 7A–C ), photos examined . Holotype of Epicadinus trispinosus : male, FRENCH GUIANA, Cayenne , 1868–1871, C. Jelski (MIZ 500 0 0 0, Figs 7D–G ), photos examined . Holotype of Epicadinus trifidus : female, MEXICO, Veracruz, Atoyac, H. H. Smith ( OUMNH 1278.2 , ex coll. Goldman & Salvin, not found).

Additional material examined. BOLIVIA: 1 male, “chaco” ( MNHN coll. Simon 18020) . BRAZIL: 1 female, December 1919, H. S. Parrish ( MCZ) . Acre: 1 male, Cruzeiro do Sul, Parque Nacional da Serra do Divisor , ca. 8°23'10"S, 73°09'30"W, 15 March 1997, L. Resende & S. Vieira ( IBSP 12368 ) . Amazonas: 1 male, alto [Rio] Solimões , ca. 4°20'50"S, 67°33'22"W, December 1979 -1980, A. Lise et. al. ( FZBRS 8939 ) ; 1 female, Tefé , ca. 3°19'09"S, 64°42'30"W, December 1919, H. S. Parrish ( MCZ) . São Paulo: 7 females, Primavera, Usina Hidrelétrica Sérgio Motta, ca. 22°29'21"S, 52°57'06W, January–February 2000, IBSP ( IBSP 29882 ) . ECUADOR: Orellana: 1 female, 2 juveniles, Parque Nacional Yasuní , ca. 1°05'48"S, 75°48'44"W, 2–5 December 2009, L. R. Benavides ( UFMG 3922 ) . MEXICO : Campeche: 1 male, 1 female, " El tormento" forest station, 18°37'00"N, 90°48'00"W, 11–12 July 1983, W. Maddison ( MCZ) . Chiapas: 1 female, Palenque Ruins , ca. 17°28'36"N,

92°02'59"W, 2–11 July 1983, R. S. Anderson ( MCZ). Tabasco: 1 female, Grutas de Coconá, 17°33'00"N, 92°55'59"W, 7 July 1983, W. Maddison ( MCZ). PANAMA: Arraiján: 1 male, 1 female, ca. 8°58'49"N, 79°40'24"W, 6 July 1950, A. M. Chickering ( MCZ). Canal Zone: 3 males, Barro Colorado Island, ca. 9°09'09"N, 79°50'46"W, May 1964, A. M. Chickering ( MCZ); idem, 1 male, 2 juveniles, 6 February 1958 ( MCZ); idem, 1juvenile 29 June 1939, ( MCZ); idem, 1 male July 1939 ( MCZ); idem, 3 females, June 1950 ( MCZ); idem, 3 females, 20 February 1950 ( MCZ); idem, 1 female, 0 4 August 1939 ( MCZ); 1 female, Exp. Gardens, ca. 9°04'24"N, 79°38'49"W, 26 July 1964, A. M. Chickering ( MCZ); idem, 2 females, 13 July 1954 ( MCZ); 1 female, Forest Reserve, ca. 9°09'26"N, 79°45'21"W, 25 July 1954, A. M. Chickering ( MCZ); idem, 1 male, 1 female, 8 January 1958, ( MCZ); idem, 1 juvenile, 23 July 1950 ( MCZ); idem, 1 male, 14 February 1958 ( MCZ). PERU: Loreto: 1 female, Pebas, [M. de Mathan] ( MHNH, Coll. Simon 2044a). TRINIDAD Y TOBAGO: 1 juvenile, Balandra Bay, ca. 10°40'36"N, 61°30'57"W, April 1922, Reynolds ( MCZ); 1 juvenile, Port of Spain, ca. 10°43'13"N, 61°00'05"W, no date, R. Thaxter ( MCZ); 1 male, Simla, ca. 10°21'37"N, 61°18'06"W, 16 April 1964 ( MCZ).

Diagnosis. E. trispinosus belongs to the trispinosus -group and is similar to E. biocellatus . Females of E. trispinosus are distinguished from E. biocellatus by the carapace presenting a longitudinal, median yellowish stripe between two light brown stripes, and by the opisthosoma with posterior triangular portion, anterior margin slightly concave and projected on the carapace, and posterior conical tubercle much higher than the opisthosoma ( Fig. 5C ). The epigynum is longer than wide, with a deep and well delimited atrium, a median septum and copulatory openings located at the edges of the epigynal plate ( Fig. 5D, E ). Its copulatory ducts do not contour the spermathecae margin ( Fig. 5F ). Males of E. trispinosus are distinguished from E. biocellatus by their reddishbrown carapace and by a light strip separating two dark brown stripes, femur and patella I and II brownish, contrasting strongly with the other yellowish articles, and the pentagonal opisthosoma is distinctive by the posterior conical projection smaller than the lateral pair ( Figs 6A, C ). RTA is approximately 2x longer than wide, with ventral fold margin describing a long convex curve, very conspicuous basal pouch in ventral view, and very long, hook-shaped DTA (almost as long as RTA, Figs 6F, G ).

Notes. Taczanowski (1872) based Thomisus cornutus on a female holotype ( Figs 7A–C ), deposited in the MIZ. In the same work, eleven pages later, the author described Thomisus trispinosus (type-species of Epicadinus ) based on a male holotype ( Figs 7D–G ). The two specimens are from Cayenne, French Guiana. The analysis of abundant material from western Brazil and bordering countries, as well as Central America and Mexico, revealed the presence of only one male morphotype, corresponding to E. trispinosus , and one female morphotype, matching with E. cornutus , often occurring in the same locality or in nearby areas. In addition to the congruence of localities, the longitudinal median yellowish stripe in the carapace and the compatibility of genital features (short embolus and short copulatory ducts, long ATD in palpus and deep lateral fovea at the epigynum strongly suggests synonymy between these species. As both species have been described in the same paper, we had to apply the principle of the first reviewer ( ICZN 1999: article 24.2). Notwithstanding the page priority criterium, we choose to keep Epicadinus trispinosus as the valid name over its synonym Epicadinus cornutus . Therefore, the valid name of the type species of Epicadinus remains Epicadinus trispinosus for the sake of the stability and universality of nomenclature, following ICZN Recommendation 24A.

The specimen described by Mello-Leitão (1929) as the female of E. trispinosus does not belong to this species, as he indicated that the three opisthosomal projections were of similar size. It may belong to E. biocellatu s, but we are not sure as we had not found any female specimen identified by Mello-Leitão as E. trispinosus . Moreover, the short description this author provided does not allow a precise identification. Another species described for the area of occurrence of E. trispinosus is Eripus trifidus , based on a holotype female from Veracruz, Mexico. In spite of the disappearance of the holotype, the extensive original description and the good illustrations of Eripus trifidus given in the “ Biologia Centrali Americana " ( O. Pickard-Cambridge 1893: fig. 12) allowed the proposed synonymy with Epicadinus trispinosus . This conclusion is corroborated by the distinct shape of the long and vertically oriented median opisthosomal projection. Besides, the only species of the genus we have been able to found in Mexico and Central America is E. trispinosus , represented by abundant material from both sexes.

Description. Female (UFMG 3922, Figs 5A–C ). Total length: 3.91. Carapace: length 2.07, width 2.05, height 1.60. Clypeus: height 0.20. Chelicerae: length 0.38, width 0.28. Sternum: length 0.96, width 0.87. Endites: length 0.24, width, 0.19. Labium: length 0.07, width 0.35. Eye diameters and interdistances: AME 0.06, ALE 0.07, PME 0.05, PLE 0.04, AME–AME 0.13, AME–ALE 0.10, ALE–ALE 0.31, PME–PME 0.17, PME–PLE 0.09, PLE–PLE 0.48. MOQ trapezoidal. Legs 1243. Leg I: femur 2.41, patella 0.88, tibia 2.06, metatarsus 1.58, tarsus 0.72, total 7.67; II: 2.34-0.97-1.77-1.41-0.79-7.30; III: 0.87-0.66-0.74-0.54-0.44-3.27; IV: 0.94-0.62-0.78-0.60-0.46-3.42. Paired macrosetal tubercles in tibiae and metatarsi not especially long or robust, shorter than half the width of the article. Opisthosoma: length 1.84, width 2.72, height 3.41, pentagonal, ending in a short terminal projection carrying the spinnerets (due to the posterior tubercle oriented perpendicularly). Anterior margin of opisthosoma slightly concave and with anterior angles slightly projected over the posterior slope of the carapace. Paired conical projections with acute apex directed posterolaterally. Posterior conical projection more than twice as long as paired ones, pointing vertically and much higher than the opisthosoma itself, arranged perpendicularly to venter of the opisthosoma. In lateral view, dorsum with anterior portion strongly concave up to the posterior conical tubercle and posterior portion slightly concave.

Epigynum ( Fig. 5D, E ) longer than wide. The ellipsoid atrium is about ¾ wider than long, located anteriorly, with a deep central depression and two lateral foveas, which are deeper than central area. Each fovea is covered by a thin, translucent chitinous keel, which tapers toward posterior portion, where it disappears. Median septum almost as wide as long, totally fused to surface of plate with anterior basis extending into the atrium and wider than posterior base, which is located a little behind the copulatory pores and distant from the atrium. Copulatory openings exposed, appearing as deep pits. Epigynum bordered by cilium-shaped bristles. Vulva ( Fig. 5F ) with slightly sclerotized ventral copulatory ducts, which expand to form a large sclerotized, very dilated and reniform anterior curve (secondary spermatheca). From the external lower angle of this structure, a sinuous duct originates, curved initially in ventral and internal direction and with the final part curved dorsolaterally, connecting to the inferior internal margin of the spermathecae, that are rounded and well developed.

Coloration ( Figs 5A–C ). Carapace yellow with two light brown longitudinal stripes, separated by a thin stripe of the carapace color, and light brown irregular marginal stripes. Sternum, endites and labium predominantly light yellow. Light yellow chelicerae each with a medium longitudinal light brown stripe. Legs I and II uniformly light yellowish. Legs III and IV predominantly light yellow with irregular brown spots. Opisthosoma predominantly yellow, including the three conical projections, whose tips are white, due to guanine spots. Dorsally, a dark yellow median stripe between two marginal white stripes (guanine) and two rounded black spots near the bases of each of the paired conical projections in the median portion of the opisthosoma. Ventrally, predominantly yellow and with white hues, sigils brown.

Male (FZBRS 8939, Figs 6A–C ): Total length: 2.64. Carapace: length 1.08, width 1.29, height 0.78, with three rows of median macrosetae and six rows of macrosetae placed between the radial furrows, besides other irregularly distributed macrosetae. Posterior portion of the carapace with a small marginal area without macrosetae. Clypeus: height 0.12. Chelicera: length 0.30, width 0.21. Sternum: length 0.58, width 0.87. Endites: length 0.23, width, 0.18. Labium: length 0.09, width 0.18. Eye diameters and interdistances: AME 0.05, ALE 0.06, PME 0.05, PLE 0.03, AME–AME 0.01, AME–ALE 0.06, ALE–ALE 0.23, PME–PME 0.11, PME–PLE 0.07, PLE–PLE 0.34. MOQ trapezoidal. Legs 1243. Leg I: femur 1.08, patella 0.42, tibia 0.90, metatarsus 0.67, tarsus 0.45, total 3.52; II: 1.00-0.47-0.73-0.56-0.44-3.20; III: 0.54-0.25-0.46-0.34-0.33-1.92; IV: 0.63-0.29-0.53-0.33-0.30-2.08. Paired macrosetal tubercles in the tibiae and in metatarsi, with length less than or equal to half the width of the article. Opisthosoma: length 1.31, width 1.84, height 1.42, pentagonal, covered by abundant macrosetae of variable size. Anterior margin of opisthosoma almost straight and barely projecting on the posterior portion of the carapace. Paired conical projections bigger than the posterior one, placed in the median portion, arranged transversally, with their acute apex directed posterolaterally. Posterior conical projection smaller than median ones, measuring about 1/3 of the height of opisthosoma. In lateral view, dorsum slightly convex, almost flat, with all projections directed back and upwards and the median one less inclined than the others.

Palpus ( Figs 6D–G ) with tegular furrow at 4 o’clock position. Embolus basis gradually separating from tegulum, initially forming a wide stripe, that becomes gradually thinner up to the filiform apex, describing about 3/ 5 of a turn around the lateral margin of the tegulum, but with the apex located on a furrow placed on the prolateral margin of the glabrous apical area of the cymbium. RTA fused to DTA, both connected directly to the tibia. An openwide U-shaped angle placed between the RTA and DTA. RTA wide and not much elongated, about 2x longer then wide, almost parallel to the longitudinal axis of the cymbium in retrolateral view, especially in its distal half, with wide median concavity and wide marginal folds, and a curved apex, elongated and thinner than the median portion of RTA. Dorsal fold projected on median concavity, forming a marginal trough in its distal half. Ventral fold large describing a long convex curve, projected gradually over the median concavity at its basal area, where it extends dorsally, forming a deep, wide basal pouch around the ventral margin of RTA and only part of base of DTA. Basal pouch of RTA very conspicuous in ventral view and with well separated and evident grooves along its extension, which confer a scaly aspect to its surface. DTA very long, hook-shaped and slightly blunt, with the base much thicker than the apex and inner face covered with numerous grooves very close together.

Coloration. Carapace reddish-brown with a median pair of dark brown longitudinal stripes, separated by a thin stripe of the same shade of the carapace, and dark brown marginal irregular stripes. Sternum, endites and labium predominantly yellow. Yellowish chelicerae each with a medium longitudinal light brown stripe. Legs I and II with patella and distal half of the femur predominantly dark brown, tibia and metatarsus light yellow and brown tarsus. Legs III and IV predominantly yellow and with irregular dark brown spots. Opisthosoma with a median dark yellow pyriform stripe between two marginal white stripes and two black rounded spots on its dorsal median portion. Conical projections mostly reddish brown, but yellow at its lower side. Laterally yellow and white-guanine hues predominate, and ventrally yellow and brown hues.

Distribution. Epicadinus trispinosus has the largest distribution in the genus, occurring from Mexico, through Trinidad and Tobago, French Guiana, Ecuador, Peru and Bolivia, to Brazil, where it reaches south to northwestern São Paulo state ( Fig. 15 ).

Figures

FIGURE 5. Epicadinus trispinosus (Taczanowski, 1872), female (UFMG 3922). A–C habitus (A dorsal, B ventral, C lateral); D–E epigynum ventral; F vulva dorsal). Abbreviations, A, atrium; AC, anterior curve of copulatory duct; CD, copulatory duct; CO, copulatory opening; MS, median septum; TK, translucent keel. Scale bars: A–C, 1 mm; D–F, 0.1 mm.

FIGURE 6. Epicadinus trispinosus (Taczanowski, 1872), male (FZBRS 8939). A–C habitus (A dorsal, B ventral, C lateral); D–G left male palpus: (D–E ventral, F retrolateral, G tibial apophysis retrolateral). Abbreviations, BP, basal pouch; DTA, distal tibial apophysis; E, embolus; EA, embolus apex; RTA, retrolateral tibial apophysis; TF, tegular furrow. Scale bars: A–C, 1 mm; D–G, 0.1 mm.

FIGURE 7. A–C Epicadinus cornutus (Taczanowski, 1872), female holotype (MIZ 500 001) (A dorsal habitus, B lateral habitus, C original label). D–G Epicadinus trispinosus (Taczanowski, 1872), male holotype (MIZ 500 000) (D dorsal habitus, E cephalotorax ventral, F left palpus retrolateral, G original label). Scale bars: A, B, D 1 mm; E, F 0.1 mm. Photo credits: A–G, Wioletta Wawer and MIZ Laboratory of Arachnology crew.

FIGURE 15. Geographic distribution records of Epicadinus, highlighting the type-locality of each of the four species (star symbols).