Chrysometa triangulosa, Salgueiro-Sepúlveda & Álvarez-Padilla, 2018

Salgueiro-Sepúlveda, F. Javier & Álvarez-Padilla, Fernando, 2018, New species of the orb-weaving spider genus Chrysometa (Araneae, Tetragnathidae) from oak forests near of the Pico de Orizaba National Park (Veracruz, Mexico), Zootaxa 4450 (3), pp. 301-330 : 306-309

Chrysometa triangulosa new species

Figures 3 , 4 , 19

Type material. Holotype ( CNAN-T1180 ). Female from Pico de Orizaba National Park, Atotonilco Calcahualco, Veracruz, Mexico. Plot I: 19° 8' 17.4" N, 97° 12' 16.2" W, 2,300 m . , May 21–30, 2012. Allotype ( CNAN-T1181 ). Male from same locality. Paratypes. Seven females and two males. Types are deposited in the Colección Nacional de Arácnidos ( CNAN) at the Instituto de Biología ( IBUNAM).

Etymology. The species epithet is from the Latin noun triangulum (triangle) and refers to the form of the septum and the transverse bar.

Diagnosis. Females of C. triangulosa can be distinguished from all sympatric species by the following features: transverse bar without arms, septum and transverse bar triangular in shape and copulatory openings located at sides of the transverse bar ( Figs. 3D , 4D ). Males of C. triangulosa are distinguished from C. brevipes , C. puebla and all sympatric species by the following features: large and triangular cymbial ectobasal process orientated ventrally, cymbial ectomedian process square and small and a large spoon-shaped conductor ( Figs. 3I , 4A, B, C ). Chrysometa brevipes and C. puebla males have a smaller cymbial ectobasal process, a rectangular cymbial ectomedian process and a smaller and pointed paracymbium lower prong.

Description. Female. Total length 5.4. Cephalothorax: length 2.1, width 1.6. Carapace pale-yellow, dark brown patterns over the cephalic region narrowing in the middle and towards the fovea ( Fig. 3A ). Ocular area darkbrown below the median eyes and pale yellow below the lateral eyes. Eyes subequal in size ( Fig. 3G ). AME diameter 0.12, PME 0.14, ALE and PLE 0.12. Chelicerae brown, darker in the tips and brighter on sides, with few scattered setae and cuticle smooth ( Fig. 3B, G ). Endites longer than wide, dark-brown, brighter in the tip, internal margins pale-yellow. Labium wider than long, same color as the endites. Sternum dark-brown, wider between the first and second legs ( Fig. 3C ). Abdomen: brown, dorsally covered with guanine silvery patches, lateral and anterior part darker with a Y-shape pattern from the middle to the spinnerets, surrounded by patches of guanine ( Fig. 3A, B ); ventrally brown, guanine patches concentrated in four spots forming a central rectangle between spinnerets and epigynum, one yellow spot on each side of spinnerets ( Fig. 3C ). Leg lengths: I 11, II 7.6, III 4.5 and IV 6.1. Legs pale-yellow, darker on joints, with ventral and dorsal dark-brown spots. First pair considerably larger. Tarsi dark-brown. All segments tips dark-brown. Epigynum: epigynal plate oval, wider than long, transverse bar and septum in triangular shape, with margins well sclerotized and darker; transverse bar with the anterior area wider, septum dark-brown and sclerotized. Copulatory openings located at the sides of the transverse bar, in sclerotized depressions ( Figs. 3D , 4D ). Spermathecae, copulatory ducts and fertilization ducts as shown in Figure 3E, F .

Male. As in female except as noted. Total length 3.8. Cephalothorax: length 2, width 1.6. Carapace: dorsal coloration darker, without dark brown patterns over the cephalic region. Ocular area brown below the median eyes and yellow below the lateral eyes. Eyes subequal in size ( Fig. 3H ). AME diameter 0.1, PME 0.14, ALE and PLE 0.11. Chelicerae dark-brown, larger and narrower, cuticle rugose, setae bases enlarged and more abundant at base ( Fig. 3H ). Abdomen: anterior dorsal part with a darker rectangular pattern, longer than wide, ventrally darker, patterns weaker than in female. Leg lengths: I 14.8, II 9.4, III 4.6 and IV 6.8. Pedipalp: CEBP shaped as a long triangular wedge, curved anteriorly, distal portion detached from the cymbium ( Figs. 3I , 4A, B, C ). Paracymbium C-shaped in retrolateral view, ( Fig. 4B ). UpP larger and wider than LwP in ventral view ( Figs. 3I , 4A ). LwP wedge-shaped, curved anteriorly ( Figs. 3I , 4A, B ). Embolus thin and short, tubular; EBA short and curved in apical region, conductor large spoon-shaped ( Figs. 3I , 4A, B, C ). Conductor and EBA in ventral view as in Figures 3I , 4A .

Variation. Female total length 3.9–5.4, cephalothorax length 2–2.3, cephalothorax width 1.4–1.8. Male total length 3.8–4.4, cephalothorax length 2–2.1.

Material examined. N=11. Mexico: Veracruz, Atotonilco Calcahualco , eight females, three males Plot I: 19° 8' 17.4" N, 97° 12' 16.2" W, 2,300 m., May 21–30, 2012. Colección Nacional de Arácnidos ( CNAN) at the Instituto de Biología ( IBUNAM) .

Distribution. Veracruz, Mexico. Known only from the type locality ( Fig. 19 ).

Biology. Specimens were collected in a Quercus forest with secondary plant growth. All specimens were found only in the plot I of the first expedition (May 21–30, 2012). Most specimens were captured by direct collecting at night; only three specimens were caught by beating over vegetation.

Figures

FIGURE 3. Chrysometa triangulosa n. sp., female. A, habitus dorsal view. B, lateral view. C, ventral view. D, epigynum ventral view. E, epigynum ventral view (cleared). F, dorsal view (cleared). G, prosoma anterior view. Male. H, prosoma anterior view. I, pedipalp ventral view. Scale bars, A, B, C, 1.0 mm; D, E, F, 0.2 mm; G, H, I, 0.5 mm.

FIGURE 4. Chrysometa triangulosa n. sp., male. A, pedipalp ventral view, B retrolateral view. C, dorsal view. Female. D, epigynum ventral view. E, posterior view. Scale bars, 0.2 mm.

FIGURE 19. Species Distribution Map. Atotonilco Locality: Chrysometa citlaltepetl, C. triangulosa, C. rosarium, C. atotonilco and C. sagicuta.. Xamaticpac Locality: C. xamaticpac, C. puya and C. chipinque.