Acusilas coccineus Simon, 1895

Sankaran, Pradeep M. & Sebastian, Pothalil A., 2018, Phonognatha vicitra Sherriffs, 1928 - a taxonomic misidentification of the orb-weaving spider Acusilas coccineus Simon, 1895 (Araneae, Araneidae), Zootaxa 4434 (2), pp. 391-395 : 391-393

publication ID	https://doi.org/ 10.11646/zootaxa.4434.2.12
publication LSID	lsid:zoobank.org:pub:59AC5853-387B-4268-BBEB-7CB5B04C261F
DOI	https://doi.org/10.5281/zenodo.5989052
persistent identifier	https://treatment.plazi.org/id/343687A0-FFBB-7A66-B6AE-F8F62E784425
treatment provided by	Plazi
scientific name	Acusilas coccineus Simon, 1895
status

Treatment

Acusilas coccineus Simon, 1895 View in CoL ( Figs 1–3 View FIGURE 1 View FIGURE 2 View FIGURE 3 )

Acusilas coccineus Simon, 1895: 785 View in CoL (Description of female); Uyemura, 1939: 142, figs a–f (Illustration of female); Yaginuma, 1960: 59, fig. 58 (Illustration of female); Namkung, 1964: 37, fig. 23 (Illustration of female) [See World Spider Catalog for complete list].

Phonognatha vicitra Sherriffs, 1928: 183 , figs 1–2 (Misidentification; description & illustration of female). Phonognatha vicitra

Sherriffs, 1928: INDIA: Karnataka: Kodagu/ Coorg: Siddapura/ Sidapur: Charlotte estate/division, W. R. Sherriffs leg.,

December, repository unknown, possibly BMNH, 7 females; not examined. Topotype specimens were examined. New

synonymy.

Additional specimens examined. INDIA, Kerala: Kollam: Kulathupuzha Forest Reserve, 8o54'6.37''N, 77o3'51.70''E, 134 m alt., 31 July 2013 GoogleMaps , M. S. Pradeep leg., from rolled dried leaf retreat in web, by hand: 1 female ( ADSH 090903 A); Ernakulam, Kurisumudi in Malayatoor , 10o12'33.36''N, 76o30'08.85''E GoogleMaps , 94 m. alt., 4 December 2013, M. S. Pradeep leg., from rolled dried leaf retreat in web, by hand: 1 female ( ADSH 090903 B); Kottayam, Kanakappalam in Erumely , 9o27'16.08''N, 76o50'43.54''E GoogleMaps , 101 m. alt., 23 August 2014, M. S. Pradeep leg., from rolled dried leaf retreat in web, by hand: 1 female ( ADSH 090903 C); Trivandrum, Patani in Ponmudi , 8o45'35.79''N, 77o7'00.75''E GoogleMaps , 920 m. alt., 0 4 October 2014, M. S. Pradeep leg., from rolled dried leaf retreat in web (males from the retreat of one of the females), by hand: 2 males, 3 females (ADSH 090903 D); Idukki, Kattappana, 9o45'24.61''N, 77o07'00.71''E; 900 m. alt., 2 April 2015, M. J. Mathew leg., from rolled dried leaf retreat in web, by hand: 10 females ( ADSH 090903 E). Karnataka: Kodagu / Coorg, Siddapura/ Sidapur, Charlotte estate/division, 12o17'5''N, 75o50'50''E GoogleMaps , 922 m. alt., 13 November 2017, M. S. Pradeep & Jimmy Paul leg., from rolled dried leaf retreat in web, by hand: 9 females (ADSH 090903 F).

Diagnosis. Males of A. coccineus can be distinguished from other congeners by the black and slender embolus with a truncated tip (E; Fig. 2A View FIGURE 2 ). Females can be separated from other members of the genus by an anteriorly wide epigynal septum (Se; Fig. 2D, F View FIGURE 2 ) (see Schmidt & Scharff (2008) for a proper differential diagnosis).

Redescription. Male (ADSH 090903 D; Figs 1C View FIGURE 1 , 2C View FIGURE 2 ) in alcohol. Carapace, clypeus, chelicerae, sternum, labium, maxillae, legs olive-brown. Ocular area slightly black. Cheliceral promargin with four teeth, retromargin toothless; chelicerae basally provided with pro and retrolateral condyles ( Fig. 2C View FIGURE 2 ). Opisthosoma nearly oval, creamy-white, hirsute; dorsum mottled with black patches and grayish spots; laterals and venter with black striations. Legs with black annulations. Body length 3.21. Carapace length 1.55, width 1.11. Opisthosoma length 1.66, width 1.32. Eyes diameter: ALE 0.07. AME 0.12. PLE 0.09. PME 0.10. Eye interdistances: ALE–PLE 0.02. AME–ALE 0.04. AME–AME 0.12. AME–PME 0.12. PME–PLE 0.13. PME–PME 0.10. Clypeus height at AME 0.04, at ALE 0.13. Length of chelicerae 0.66. Measurements of pedipalp and legs: Pedipalp 1.14 [0.34, 0.14, 0.14, 0.52], I 3.14 [1.01, 0.48, 0.73, 0.53, 0.39], II 3.07 [0.94, 0.45, 0.64, 0.60, 0.44], III 2.01 [0.65, 0.32, 0.37, 0.35, 0.32], IV 2.79 [0.88, 0.45, 0.60, 0.48, 0.38]. Leg formula: 1243. Pedipalp as in Fig. 2A–B View FIGURE 2 .

Female (ADSH 090903 D; Fig. 1A–B View FIGURE 1 ) in alcohol. Like male, except the following. Carapace, clypeus, chelicerae, labium, maxillae, sternum, palpal segments, legs, spinnerets tan coloured. Cephalic groove prominent ( Fig. 1B View FIGURE 1 ). Cheliceral promargin with four teeth, retromargin with three, 2nd promarginal tooth largest; chelicerae lack condyles. Opisthosoma oblong; dorsum with prominent dark patches on white folium. Body length 10.24. Carapace length 4.09, width 3.27. Opisthosoma length 6.15, width 4.46. Eyes diameter: ALE 0.14. AME 0.26. PLE 0.19. PME 0.22. Eye interdistances: ALE–PLE 0.03. AME–ALE 0.09. AME–AME 0.18. AME–PME 0.18. PME–PLE 0.28. PME–PME 0.17. Clypeus height at AME 0.10, at ALE 0.25. Length of chelicerae 1.54. Measurements of palp and legs: Palp 3.82 [1.24, 0.52, 0.78, 1.28], I 10.79 [3.28, 1.57, 2.44, 2.28, 1.22], II 10.04 [3.16, 1.51, 2.22, 2.04, 1.11], III 6.60 [2.08, 1.14, 1.34, 1.15, 0.89], IV 10.46 [3.24, 1.63, 2.29, 2.25, 1.05]. Leg formula: 1423.Genitalia as in Fig. 2D–E View FIGURE 2 .

Variation. Female: Body length 7.52–13.31 (n = 25). The female genitalia show slight variations particularly in the shape of the median septum and the shape and orientation of the copulatory ducts (e. g. see Fig. 2D–G View FIGURE 2 ).

Justification of the synonymy. Sherriffs (1928) cited that P. vicitra had a narrow cephalon, which was separated from the thoracic part by a shallow groove. Females with narrow cephalon, which is clearly demarcated from the thoracic region by a prominent groove is one of the characteristic features of the genus Acusilas ( Schmidt & Scharff 2008: fig. 6A; herein Fig. 1B, D View FIGURE 1 ). Specimens collected from the Charlotte estate/division show all the diagnostic features of the genus Acusilas : narrow cephalon clearly demarcated by a prominent cephalic groove ( Fig. 1D View FIGURE 1 ), AME closer to ALE than to each other, strongly recurved PER and epigynum with a transverse rim (AR; Fig. 2F View FIGURE 2 ) ( Schmidt & Scharff 2008). All these clearly indicate that P. vicitra is a misplaced species in Phonognatha and is indeed a member of Acusilas . According to Sherriffs (1928), the opisthosomal pattern of P. vicitra consists of laterally placed dark patches on a white folium, which is the opisthosomal pattern of A. coccineus ( Schmidt & Scharff 2008; compare Fig. 1B, D View FIGURE 1 with Sherriffs 1928: fig. 1). Further, detailed examination of the genitalia of P. vicitra ( Fig. 2F–G View FIGURE 2 ) collected from the Charlotte estate/ division has all the diagnostic features of A. coccineus including anteriorly wide epigynal septum and copulatory ducts visible without clearing the epigynum. Based on these observations we regard P. vicitra as a junior synonym of A. coccineus .

Note. Schmidt & Scharff (2008: figs 8A, 9B–C, 17A) observed the occurrence of broken-off emboli (that function as mating plug) in the copulatory ducts of both Acusilas africanus Simon, 1895 and Acusilas malaccensis Murphy & Murphy, 1983 and suggested that such mating plug might be found in other Acusilas species also. In agreement with their opinion, an embolic mating plug was observed in the copulatory ducts of one of our female specimens ( Fig. 1E View FIGURE 1 , arrows) collected from the Charlotte estate/division. This is the first record of a mating plug in A. coccineus .

Distribution in India. Karnataka ( Sherriffs 1928, present data), Kerala (present data), West Bengal ( Roy et al. 2017) ( Fig. 3 View FIGURE 3 ). Roy et al. (2010) recorded Acusilas from the tea ecosystem of Assam. However they failed to identify their species and suggested that it might be A. coccineus . Due to uncertainty of species identification, their record is omitted here.