Arachnura melanura Simon, 1867

Sen, Souvik & Sureshan, Pavittu M., 2020, Rediscovery of the scorpion tailed orb-weaver, Arachnura melanura Simon 1867 (Araneae: Araneidae) from India, Records of the Zoological Survey of India 120 (3), pp. 285-288 : 286-287

Arachnura melanura Simon, 1867

1867. Arachnura melanura Simon, Revue et Magasin de Zoologie Pure et Appliquée , 19 (2): 17.

Materials examined: 2♀ (ZSI/ WGRC /IR.INV/12483 and 12484), India: Kerala, Valavattey, Neyyar Wildlife Sanctuary (08°31’58”N & 77°08’48”E, 87m), 17.i.2019, coll. Jafer Palot.

Diagnosis: Females of Arachnura melanura Simon resemble A. angura Tikader but differ distinctly by the shape of the epigynum, which is wider than long with sclerotized epigynal scape, and distinct lateral lobes ( Figure 4 ), but nearly subquardrate epigynal scape without lateral lobes in A. angura . Further, spermatheca of A. melanura is nearly spherical with long outwardly curved copulatory ducts and distinct fertilization ducts ( Figure 5 ), but spermatheca globular with short inwardly curved copulatory ducts and indistinct fertilization ducts in A. angura .

Description: Female: TL 12.38, CL 3.13, CW 2.25, AL 9.25, AW 3.21. Cephalothorax ( Figure 1 ) longer than wide and narrowing in front, yellowish brown with a distinct grey median strip and grey patches as flank, cervical groove grey. Eyes small, transparent, ringed with black, anterior row more recurved than posterior, laterals and anteromedians on tubercles, MOA longer than wide, inter ocular distance: AME–AME 0.31, ALE–AME 0.40, PME– PME 0.07, PLE–PME 0.45, ALE–PLE 0.19, AME–PME

0.27, ALE–ALE 0.87, PLE–PLE 0.95. Sternum nearly heart-shaped, yellowish brown with a light greyish patch on middle. Labium yellowish brown, wider than long, apical margin narrowed, pale and scopulate. Maxillae longer than wide with pale inner margin, scopulate ( Figure 2 ). Chelicerae yellow, longer than wide; fangs yellowish brown, weak; teeth small yellow brown, promargin with 4 and retromargin with 3 teeth. Leg segments with varying shades of brown; tarsi, tibia and metatarsus I-IV with distinct black band, such band light in tarsi IV, femora dorsally with black shades; tibia, metatarsus and tarsus clothed with macrosetae. Leg measurements: I 6.61 (2.24,

0.78, 1.87, 1.27, 0.45); II 7.12 (2.39, 0.82, 1.92, 1.43, 0.56); III 4.47 (1.44, 0.76, 0.98, 0.90, 0.39); IV 6.51 (1.74, 1.17,

1.42, 1.46, 0.72). Leg formula 2 1 4 3.

Abdomen yellowish brown, elongated, with a anterior deep central bifurcation forming two pointed shoulder humps, posteriorly forms a tail like process which extends beyond the spinnerets with 3 protuberance, median one longer than laterals, each with a conspicuous white tip; sigilla 2 pairs, light grey, small, inconspicuous ( Figures 1&3 ); venter greyish brown with few scattered yellowish spots near epigastric furrow, tail yellowish brown with grey shades. Spinnerets apically brown, basally dark brown ( Figure 2 ).

Epigynum-internal genitalia: epigynal scape wider than long (broadly U-shaped), sclerotized, rebordered posteriorly, with distinct lateral lobes ( Figure 4 ); spermatheca dark brown, nearly spherical and sclerotized, copulatory ducts long, thick, outwardly curved, outer margin rebordered, fertilization ducts distinct, thin, half the size of copulatory ducts ( Figure 5 ).

Distribution: India ( Roewer, 1942; present paper), China ( Song, Zhu & Chen, 1999; Yin et al., 2012), Malaysia ( Roewer, 1942; Uyemura, 1976b), Indonesia ( Roewer, 1942; Chrysanthus, 1961), Taiwan ( Uyemura, 1976a), Japan ( Tanikawa, 1991, 2007); Australia ( Castanheira et al., 2019) and Papua New Guinea ( World Spider Catalog, 2020).

Figures

Figures 1–5. Arachnura melanura Simon, female: 1. Habitus, dorsal view, 2. Same, ventral view, 3. Tip of abdominal tail, 4. Epigynum, ventral view, 5. Internal genitalia, dorsal view. Scale bars= (1, 2, 4) 0.5 mm, (3, 5) 0.3 mm. Abbreviations: S = Scape, L = Lateral lobe, Sp = Spermatheca, Cd = Copulatory duct, Fd = Fertilization duct, Co = Copulatory opening.