Epicadus dimidiaster, Machado & Teixeira & Lise, 2018

Machado, Miguel, Teixeira, Renato Augusto & Lise, Arno Antonio, 2018, There and back again: More on the taxonomy of the crab spiders genus Epicadus (Thomisidae: Stephanopinae), Zootaxa 4382 (3), pp. 501-530 : 508-510

Epicadus dimidiaster sp. nov.

Figs 3A–D , 4A–D , 16B

Type material: Holotype: female, Floresta Nacional de Caxiuanã [1°45'12"S, 51°31'14"W, Pará, Brazil], J.M.C. Cordeiro ( MPEG 30605 ).

Paratypes: 1 male, Melgaço [1°43'43"S, 51°29'00"W, Pará, Brazil], 3 October 2005, C.A. Lopes ( MPEG 30603 ) ; 1 male, same locality and collector, 8 October 2005 ( MCTP 39868 ) ; 1 female, same locality, 23 April 2006, J.A.P. Barreiro ( MPEG 29419 ) ; 1 female, same locality, 27 September 2005, N.S. Abrahim ( MCTP 39869 ) ; 1 male, Jacareacanga [6°21'27.07"S, 56°03'36.58"W, Pará, Brazil], 14 December 2009, N.S. Abrahim ( MPEG 30602 ) .

Other material examined. BRAZIL: Pará: 1 male, Jacareacanga , 6°37'29"S, 57°52'02"W, 27 October 2009, E.G. Cafofo ( MPEG 30604 ) . Amazonas: 1 male, Manaus, Reserva Florestal Adolpho Ducke, 3°00'32"S, 59°56'49"W, 26 October 1973, L.P. Albuquerque ( INPA 8003 ) ; 1 male, Coari , 4°52'51"S, 65°08'52W, October 2006, N.F. Lo Man Hung ( MPEG 13291 ) ; Acre. 1 male, Anil, Parque Nacional da Serra do Divisor , 8°22'45"S, 73°10'55"W, 11 November 1996, R.S. Vieira ( IBSP 8939 ) . Mato Grosso do Sul: 1 female, Anaurilândia , 22°09'18"S, 52°47'18"W, 12–19 March 2001, F.S. Cunha & C.A.R. Souza ( IBSP 39292 ) . São Paulo: 1 male, Jundiaí, Serra do Japi , 22°16'50"S, 47°32'53"W, 17 March 1997, A.J. Santos ( IBSP 38805 ) . COLOMBIA: Vaupés: 1 male, Estación Biologica Caparu , 1°04'00”S, 69°31'00”W, 15 October 2004, J. Pinzon ( ICN 7633 ) . PERU: Puerto Maldonado: 1 female, 3 males, Tambopata , 12°33'00”S, 69°08'00”W, 25 June –11 July 1989, D. Silva ( MUSM) .

Etymology. The specific name is the union of the words dimidius, a masculine adjective that means ‘half’, and aster, a masculine noun meaning ‘star’. The name is a reference to the shape of the female opisthosoma, which resembles the upper half of a five-pointed star. Noun in apposition.

Diagnosis. Females of E. dimidiaster sp. nov. resemble those of E. taczanowskii in the shape and proportion of the opisthosomal projections, but can be distinguished by the glabrous prosoma, absence of the upside down Vshaped mark on clypeus and thoracic portion with no LBL ( Figs 3A, B ). The epigynal plate differs from those of other species of the genus by the lateral folds that do not join posteriorly to form a median septum. Instead, the septum is formed by an anterior elevation of the median field ( Fig. 3C ). Males are almost indistinguishable from those of E. trituberculatus , being only recognizable by the pointed and stouter opisthosomal projections and by the position of TF at four o’clock ( Fig. 4C ).

Description. Female (from Floresta Nacional de Caxiuanã; MPEG 30605): Anterior eye row recurved and posterior row slightly procurved. Prosoma yellow, and pale yellow in the center of carapace and cephalic region ( Fig. 3A ) (speckled with green taints in vivo—see Fig 16B ). Chelicerae pale yellow, sternum pale yellow, scutiform and longer than wide. Labium anteriorly yellow and posteriorly pale yellow, cuneiform and longer than wide. Endites pale yellow, rounded at their tips and longer than wide. Legs pale yellow, tarsi and distal portion of metatarsi dark yellow. Opisthosoma granulated, pale yellow with white apices in the opisthosomal projections ( Figs 3A , 16B ); anterior border rounded with a central notch; opisthosomal projections conical and faced backwards, lateral and median posterior projections single-tipped, stout and conical ( Figs 3A , 16B ). Epigynal plate with a large and wide median field, elongated lateral folds curved posteriorly but not connecting with the copulatory openings; median septum discrete and projecting from the anterior region of the epigynal plate ( Fig. 3C ); secondary spermathecae well developed, wide and primary spertamathecae oval-shaped and presenting a smooth surface ( Fig. 3D ).

Measurements: eye diameters and interdistances: AME 0.15, ALE 0.17, PME 0.13, PLE 0.11, AME–AME 0.25, AME–ALE 0.14, PME–PME 0.41, PME–PLE 0.17, MOQ length 0.5, MOQ width 0.47; leg formula: 1-2-4-3: leg I—femur 3.80/ patella 2.02/ tibia 2.28/ metatarsus 1.79/ tarsus 1.21/ total 11.10; II—3.64/ 2.01/ 2.35/ 1.77/ 1.10/ 10.87; III—1.98/ 1.19/ 1.09/ 1.18/ 0.53/ 5,97; IV—2.14/ 1.00/ 1.29/ 1.35/ 0.52/ 6.30. Total body length 7.89; prosoma length 4.0, wide 3.8; opisthosoma length 4.44; clypeus height 0.38; sternum length 1.76, width 1.41; endites length 0.86, width 0.52; labium length 0.79, width 0.66.

Male (from Melgaço; MPEG 30603). Anterior eye row recurved and posterior row straight. Prosoma granulated, yellowish brown, with lateral and posterior margins brown; presence of a rectangular yellowish stain in the center of the carapace ( Figs 4A, B ). Chelicerae and fangs yellowish brown; sternum yellow with brown margins, scutiform, and as long as wide; posteriorly truncated; labium yellowish brown, cuneiform and wider than long; endites yellowish brown, with cambered retromargin, longer than wide, with brown margins. Legs I and II yellowish brown, patella yellow; legs III and IV predominantly yellowish brown ( Fig. 4A ). Opisthosoma yellow with yellowish brown scales; whitish-yellow stains in the dorsolateral regions and in the posterior face of the lateral opisthosomal projections and close to the spinnerets; anterior border of opisthosoma almost straight (with an inconspicuous notch); lateral opisthosomal projections conical and faced upwards, median posterior opisthosomal projection single-tipped, stout, conical and faced upwards ( Fig. 4A ). Male palp characterized by a pear-shaped cymbium and a filiform embolous encircling the discoid tegulum ( Fig. 4C ); RTA canoe-shaped and fused to the pointed and thin DTA ( Fig. 4D ).

Measurements: eye diameters and interdistances: AME 0.07, ALE 0.08, PME 0.05, PLE 0.04, AME–AME 0.06, AME–ALE 0.06, PME–PME 0.21, PME–PLE 0.09, MOQ length 0.24, MOQ width 0.22; leg formula: 1-2-4- 3: leg I—femur 1.14/ patella 0.54/ tibia 0.71/ metatarsus 0.55/ tarsus 0.42/ total 3.36; II—1.05/ 0.49/ 0.66/ 0.53/ 0.38/ 3.11; III—0.61/ 0.30/ 0.40/ 0.36/ 0.23/ 1.81; IV—0.70/ 0.30/ 0.44/ 0.45/ 0.22/ 2.11. Total body length 2.58; prosoma 1.35 length, 1.22 wide; opisthosoma length 1.34; clypeus 0.19 height; sternum 0.57 length, 0.55 width; endites 0.30 length, 0.18 width; labium 0.19 length, 0.23 width.

Distribution. BRAZIL: São Paulo, Mato Grosso do Sul, Acre, Amazonas and Pará; COLOMBIA: Vaupés; PERU: Tambopata ( Fig. 17D ).

Figures

FIGURE 3. Epicadus dimidiaster sp. nov., female (MPEG 30605). A, B habitus (A dorsal, B frontal); C epigynal plate (ventral); D spermathecae and copulatory ducts (dorsal). Scale bars:Scale bars: 1 mm (A, B), 0.1mm (C, D).

FIGURE 4. Epicadus dimidiaster sp. nov., male (MPEG 30603). A, B habitus (A dorsal, B frontal); C, D left palp (C frontal vieW With arroW indicating the tegular furroW (TF), D retrolateral vieW). Scale bars:1 mm (A), 0.5 mm (B), 0.1 mm (C, D).

FIGURE 16. Female specimens in vivo. A Epicadus taczanowskii (RoeWer, 1951); B Epicadus dimidiaster sp. nov.; C Epicadus rubripes Mello-Leitão, 1924 (adapted from Silva-Moreira & Machado 2016: fig. 1F); D Epicadus camelinus (O. Pickard-Cambridge, 1869); E Epicadus heterogaster (Guérin-Méneville, 1829); F Epicadus trituberculatus (TaczanoWski, 1872). Photo credits:César Favacho (A); Arthur Anker (B); Almir Cândido de Almeida (C); Karl Kroeker (D); Edson Roberto (E); Edelcio Muscat (F).

FIGURE 17. Data of distribution records of Epicadus species compiled from Machado et al. (2015, 2017); Silva-Moreira and Machado (2016); present study.