Strotarchus Simon, 1888

Bonaldo, Alexandre B., Saturnino, Regiane, Ramírez, Martín J. & Brescovit, Antonio D., 2012, A revision of the American spider genus Strotarchus Simon, 1888 (Araneae: Dionycha, Systariinae), Zootaxa 3363, pp. 1-37 : 4-12

Strotarchus Simon, 1888

Strotarchus Simon, 1888: 210 (type species by monotypy, S. nebulosus Simon, 1888 ); Bonaldo, 1994; Platnick & Bonaldo, 1995.

Bedriacum O. Pickard-Cambridge, 1898: 251 (type species by monotypy, B. praedator O. Pickard-Cambridge, 1898). Synonymised with Strotarchus by F.O. Pickard-Cambridge, 1899: 87.

Marcellina Bryant, 1931: 103 (type species by original designation, Clubiona piscatoria Hentz, 1847 ). Synonymised with Strotarchus by Edwards, 1958: 373.

Coreidon Mello-Leitão, 1917: 15 (type species by monotypy, C. tropicum Mello-Leitão, 1917 ). Synonymised with Strotarchus by Ramírez et al., 2004: 179.

Diagnosis. Members of the genus Strotarchus can be recognised by the male palp with an elongate cymbium ( Figs. 54 , 58−65 ); tegulum with widely fused retrolateral apophysis ( Figs. 70−71 , 73−74 ), without a hyaline conductor; embolus with a large base, abruptly narrowed distally, with a distinct median process ( Figs. 48−49, 51−53 ); female epigynum with an anterior atrium, forming a copulatory pocket, without conspicuous copulatory openings ( Figs. 66−69 ).

Description. Total length (males and females) 4.8−14.5. Carapace subquadrate in dorsal view ( Figs. 1, 7 ), smooth, with weak radial grooves, widest at coxae II, cephalic area poorly delimited, abruptly narrowed, except in S. planeticus , gradually narrowed; anterior margin truncated; in lateral view, thoracic area not pronounced, with gentle posterior declivity; thoracic groove longitudinal, short and shallow, longer and deeper in S. monasticus n. sp. and S. michoacan n. sp.; clypeus rebordered anteriorly, clypeal height 0.5 to 1 times AME diameter; eight eyes placed in two rows; anterior eye row straight or slightly recurved in frontal view; posterior eye row straight or slightly procurved in dorsal view; ocular quadrangle longer than wide or as long as wide in dorsal view; anterior median ocular tubercle absent; eyes circular; AME slightly larger than others. Interdistances: AME―AME separated by their diameter (as in S. tropicus ), less than half their diameter (as in S. silvae n. sp.) or half their diameter (as in S. monasticus n. sp.); AME―ALE separated by approximately half a ALE diameter or almost contiguous ( S. beepbeep n. sp., S. tlaloc n. sp., S. jacala n. sp., S. silvae n. sp. and S. tropicus ); PME―PME separated by two times their diameter (except in S. piscatorius and S. silvae n. sp., almost two times their diameter); PME―PLE by approximately a PME diameter; ALE―PLE contiguous (except in S. monasticus n. sp., separated by half a PLE diameter), not placed in a common comorus. Tapeta of indirect eyes shiny, with median darker band, not grateshaped (observed in S. piscatorius ). Chilum glabrous, entire or separated in two pieces (not completely divided in females of S. planeticus and S. michoacan n. sp.). Chelicerae slightly geniculate, with short basal condylus ( Fig. 8 ); retrolateral surface with transversal, subdistal grooves and proximal field of setae with tuberculated bases; promargin of fang furrow with 2, 3 or 4 teeth (mostly with 3), median larger; retromargin with 2 to 7 teeth (mostly with 2) of same size; cheliceral length approximately equal to half of carapace length (except in S. minor , approximately two thirds of carapace length); endites parallel, promargin slightly concave, retromargin with shallow longitudinal excavation, serrula in single row ( Fig. 12 ); labium as long as wide or longer than wide ( Fig. 14 ) (wider than long only in S. urarina n. sp.), with proximal constrictions; sternum longer than wide ( Fig. 15 ), strongly rebordered, precoxal triangles present. Leg formula: I, IV, II, III. Legs long, covered by feathery and simple hairs; tarsi and metatarsi with sparse scopula (more sparse in metatarsi); metatarsi III and IV with ventral distal clusters of black setae; two pectinate claws, with 5−6 teeth ( Figs. 33−39 ); claw tufts absent, tenent setae of tarsal scopula not projecting distally, only plumose setae apically ( Fig. 37, 38 ); tarsal organ capsulate, with circular or oblong aperture ( Figs. 16−27 ); tarsal trichobothria in 2 dorsal rows, trichobothrial base ( Figs. 28−32 ) with several elongated ridges; female palpal tarsus clavate, with one pectinate claw; all trochanters notched.

Abdomen long or suboval (as in S. tlaloc n. sp., S. tamaulipas n. sp. and S. jacala n. sp.), densely covered by feathery hairs, with sparse long simple setae; booklung spiracles narrow, margins not sclerotised; tracheal tubercle absent; colulus inconspicuous, with few setae. Spinnerets without sexual dimorphism ( Figs. 40−47 ; all spigots inferred from S. piscatorius ): anterior lateral spinnerets parallel, conical, subcontiguous, two-segmented, distal segment short, truncate, with one major ampullate gland spigot on mesal margin, posterior major ampullate gland spigot reduced to nubbin, and many piriform gland spigots ( Figs. 41, 45 ); posterior median spinnerets parallel, contiguous, one-segmented, with many aciniform gland spigots and two minor ampullate gland spigots ( Figs. 42, 46 ); posterior lateral spinnerets divergent, conical, separated by more than their diameter, two-segmented, distal segment long, conical, with many aciniform gland spigots ( Figs. 43, 47 ); females without cylindrical gland spigots on either posterior median and posterior lateral spinnerets; anal tubercle small, not modified.

Male palp: femur with three dorsal and one prolateral apical spine. Patella unmodified. Tibia with unique, apical RTA; RTA with a small ppRTA ( Fig. 73 ), except in S. minor and S. piscatorius ; apices lamellar (laRTA, Fig. 73 ) in S. nebulosus , S. monasticus n. sp. and S. tropicus . Cymbium without apical dorsal scopulae or basal projections; oval, elongate, distal portion extremely elongate, almost tubular in S. silvae n. sp., S. minor , S. piscatorius and S. urarina n. sp.; BH large; P small, triangular; ST semicircular, cup-shaped, without anelli; MH small, indistinct; T generally rounded (compact in S. silvae n. sp.), with a widely fused RTA (small in S. urarina n. sp., S. minor , S. gandu n. sp. and S. silvae n. sp.); R with three basal folds; conductor absent; E with bulk, unsclerotised basis, distal portion generally long, filiform (short, with hook-shaped apices in S. violaceus ); embolar process generally conspicuous, extremely elaborated in S. nebulosus and S. monasticus n. sp., represented only by a small distal sharp projection in S. violaceus .

Epigynum with lateral borders well defined; atrium (A) deep, located anteriorly, generally large, rounded (small in S. violaceus ; narrow in S. mazamitla n. sp., S. jacala n. sp. and S. beebeep n. sp.); ventrally composed of weakly sclerotised dorsal pocket (atrial pocket, AP), divided by a median slit, encapsulating anterior vulval elements and apparently acting as funtional copulatory openings that leads to CD; CD helicoid in most species (oval in S. mazamitla n. sp., kidney-shaped posteriorly in S. tropicus ), connected medially or anteriorly to AP, typically coiling around itself toward posterior margin of epigynum, turning anteriorly toward large, curved stalk of spermathecae; GK present as a cul-de-sac duct, inserted laterally in the anterior end of CD; SS a long, wide, curved sclerotised duct connecting CD and S; S posteriorly placed, contiguous to each other, globose (as in S. gandu n. sp.) or undifferentiated (as in S. mazamitla n. sp.); FD small, inserted dorsally in spermathecae.

Composition. Eighteen Neartic and Neotropical species. It is beyond the scope of this revision to access the two species from Pakistan described by Dyal (1935) in Strotarchus ( S. alboater and S. vittatus ). The original descriptions suggest that these species probably do not belong here, but without examination of types it is impossible to attribute these species with an acceptable degree of certainty to one of the Systariinae genera occurring in the Oriental Region.

Figures

FIGURES 54 – 57. Strotarchus piscatorius (Hentz, 1847), male, palp: 54) dorsal; 55) ventroapical; 56) retrolateral; 57) prolateral.

FIGURES 58 – 65. Strotarchus silvae new species, male, palp expanded: 58) dorsolateral; 59) ventral; 60) retrolateral; 61) prolateral. Strotarchus piscatorius (Hentz, 1847), male, palp expanded: 62) dorsal; 63) ventral; 64) prolateral; 65) retrolateral. Abbreviations: BEF—Basal embolar fold; Cy ― Cymbium; EA ― Embolar apex; EB ― Embolar basis; EP ― Embolar process; MH ― Median haematodocha; P ― Petiole; R—Reservoir; ST ― Subtegulum; T ― Tegulum.

FIGURES 70 – 72. Strotarchus violaceus F. O. Pickard-Cambridge, 1899, male: 70) palp, ventral; 71) palp, retrolateral; female: 72) epigynum, ventral. Scale bar = 0.5 mm: 70 - 71; 0.25 mm: 72.

FIGURES 73 – 80. Strotarchus praedator (O. Pickard-Cambridge, 1898), male: 73) palp, ventral; 74) palp, retrolateral. Strotarchus nebulosus Simon, 1888, female: 75) epigynum, ventral; 76) epigynum, dorsal. Strotarchus monasticus new species, male: 77) palp, ventral; 78) palp, retrolateral; female: 79) epigynum, ventral; 80) epigynum, dorsal. Scale bar = 0.5 mm: 73 - 74, 77 - 78; 0.25 mm: 75 - 76, 79 - 80. Abbreviations: A ― Atrium; AP ― Atrial pocket; BEF ― Basal embolar fold; CD ― Copulatory ducts; EA ― Embolar apex; EB ― Embolar basis; EP ― Embolar process; FD ― Fertilization ducts; GK ― Glandular knob; laRTA ― Apical lamella of Retrolateral tibial apophysis; ppRTA ― Prolateral process of Retrolateral tibial apophysis; S ― Spermathecae; SS ― Spermathecae stalk; TA ― tegular apophysis.

FIGURES 48 – 53. Strotarchus tropicus (Mello-Leitão, 1917), male: 48) palp, embolar process; 49) palp, ventral. Strotarchus tamaulipas new species, male: 50) apophysis tibial retrolateral; 51) palp, retrolateral; 52) palp, ventroapical. Strotarchus beepbeep new species, male: 53) palp, lateroventral.

FIGURES 66 – 69. Strotarchus monasticus new species, female: 66) epigynum, dorsal. Strotarchus tropicus (Mello-Leitão, 1917), female: 67) epigynum, dorsal. Strotarchus piscatorius (Hentz, 1847), female: 68) epigynum, dorsal. Strotarchus planeticus Edwards, 1958, female: 69) epigynum, dorsal. Scale bar = 0.2 mm. Abbreviations: A ― Atrium; AP ― Atrial pocket; CD ― Copulatory ducts; FD ― Fertilization ducts; GK ― Glandular knob; S ― Spermathecae; SS ― Spermathecae stalk.

FIGURES 1 – 7. Strotarchus tropicus (Mello-Leitão, 1917), carapace, female: 1) dorsal; 2) laterodorsal. Strotarchus piscatorius (Hentz, 1847), carapace, female: 3) lateral; 4) frontal; 5) dorsal; 6) lateral. Strotarchus beepbeep new species, carapace, male: 7) dorsofrontal.

FIGURES 8 – 15. Strotarchus tamaulipas new species, male, chelicerae: 8) basal condylus. Strotarchus beepbeep new species, male: 9) chelicerae, ventral. Strotarchus piscatorius (Hentz, 1847), female: 10) chelicerae, posterior; 11) chelicerae, mesal; 12) serrula; 13) maxillary glands; 14) endites and labium; 15) sternum.

FIGURES 33 – 39. Strotarchus piscatorius (Hentz, 1847), claws, male: 33) leg IV; 34 - 35) leg II; 36) female, palpal claw; 37) retrolateroapical, leg IV; 38) retrolateral, leg IV. Strotarchus beepbeep new species, claws, male: 39) retrolateral.

FIGURES 16 – 23. Strotarchus piscatorius (Hentz, 1847), tarsal organ, female: 16) Leg I; 17) Leg II; 18) Leg III; 19) Leg IV; tarsal organ, male: 20) Leg I; 21) Leg II; 22) Leg III; 23) Leg IV.

FIGURES 24 – 32. Strotarchus tropicus (Mello-Leitão, 1917), tarsal organ, female: 24) leg I. Strotarchus piscatorius (Hentz, 1847), tarsal organ, female: 25) leg I, left. Strotarchus beepbeep new species, tarsal organ, male: 26) leg II. Strotarchus tamaulipas new species, tarsal organ, male: 27) leg III. Strotarchus tropicus (Mello-Leitão, 1917), thricobothria, female: 28) tibia I; 29) tarsus I. Strotarchus piscatorius (Hentz, 1847), female: 30) tarsus I. Strotarchus beepbeep new species, male: 31 - 32) metatarsus, leg II.

FIGURES 40 – 47. Strotarchus piscatorius (Hentz, 1847), spinnerets: 40, female spinnerets; 41, female right ALS. 42, female right PMS. 43, female right PLS. 44, male spinnerets. 45, male right ALS. 46, male right PMS. 47, male left PLS. (AC ― aciniform, MAP ― major ampullate, mAP ― minor ampullate, nu ― nubbin of major ampullate, PI ― piriform).