Gasteracantha geminata ( Fabricius, 1798 )

Sankaran, Pradeep M., Jobi, Malamel J. & Sebastian, Pothalil A., 2015, Redescription of the orb-weaving spider Gasteracantha geminata (Fabricius, 1798) (Araneae, Araneidae), Zootaxa 3915 (1), pp. 147-150: 147-149

publication ID

http://dx.doi.org/10.11646/zootaxa.3915.1.10

publication LSID

lsid:zoobank.org:pub:DDAA924B-4611-4C37-AE68-1EE729C8E707

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http://treatment.plazi.org/id/038A4871-FFA5-052D-FF46-406BFBC548C7

treatment provided by

Plazi

scientific name

Gasteracantha geminata ( Fabricius, 1798 )
status

 

Gasteracantha geminata ( Fabricius, 1798) 

Aranea geminata Fabricius, 1798: 292  (Description of ♀ (Ramanathapuram, 9 o 22 ' 14.12 ''N, 78 o 50 ' 0 0.44 ''E; 10.67 m ))

Gasteracantha geminata C. L. Koch, 1837: 16  , fig. 260 (Description and illustration of ♀).

Plectana geminata Walckenaer, 1841: 158  .

Gasteracantha connata Butler, 1873: 168  (Description of ♀)

Gasteracantha rimata  O. P.- Cambridge, 1879: 282, pl. 26, fig. 3 (Description and illustration of ♀)

Gasteracantha geminata Simon, 1895: 836  , figs. 883-887 (Description of ♂ and illustrations of ♂ & ♀). Pocock, 1900: 233, fig. 79 (Description and illustration of ♀). Dahl, 1914: 267, fig. 11 (Illustration of ♀). Tikader, 1982: 53, figs. 107-110 (Description and illustration of ♀). Kim et al., 2013: 175, figs. 1-8 (Description and illustration of ♀).

Material examined. India, Kerala, Alappuzha, Pathiramanal Island (9 o 37 '07.11''N, 76 o 23 '04.95''E), 0 m, Pradeep M.S.

leg. 0 5 February 2014, by hand, 1 ♂, 3 ♀ ( ADSH 096626A). Kerala, Alappuzha, Pathiramanal Island (9 o 37 '07.11''N, 76 o 23 '04.95''E), 0 m, Pradeep M.S. leg. 22 November 2014, by hand, 2 subadult ♂, ( ADSH 096626B).

Diagnosis. G. geminata  is most similar to G. k u hl i C. L. Koch, 1837 ( Song et al. 1999, figs. 168 G-H, M, S-T). Males of G. geminata  can be easily distinguished from those of G. kuhli  by the disto-median process of conductor ( Figs. 1View FIGURE 1 C, 2 C) (absent in G. kuhli  ), reniform paramedian apophysis ( Figs. 1View FIGURE 1 C, 2 C) (circular in G. kuhli  ), median apophysis with distoretrolateral serration ( Figs. 1View FIGURE 1 C –D, 2 C –D) (median apophysis with prolateral serration in G. k u hl i) and large, dorsally inconspicuous posterior opisthosomal spines ( Figs. 1View FIGURE 1 A, 2 A) (posterior opisthosomal spines in G. k u hl i are short and dorsally conspicuous). Females can be distinguished by the M-shaped posterior border line of the epigynum ( Fig. 2View FIGURE 2 E) (posterior border line in G. kuhli  is not M-shaped), posteriorly directed fertilization ducts ( Fig. 2View FIGURE 2 F) (fertilization ducts in G. kuhli  are anteriorly directed) and the long, closely placed paired lateral opisthosomal spines ( Figs. 1View FIGURE 1 B, 2 B) (lateral opisthosomal spines in G. k u hl i are short and widely placed).

Description. Male (from Pathiramanal Island, Figs. 1View FIGURE 1 A, 2 A): Prosoma black; cephalic region provided with a midanterior projection accomodating AMEs; thoracic region provided with numerous tiny tubercles. Clypeus, chelicerae, maxillae, labium, sternum black. Opisthosoma creamy white with black patches; dorsum provided with 20 sigillae arranged as in Fig. 2View FIGURE 2 A; unlike female, lateral spines on the opisthosoma absent, posterior ones present, but difficult to distinguish in dorsal view ( Fig. 2View FIGURE 2 A); marginal and ventral opisthosoma provided with numerous tiny, pointed tubercles ( Figs. 1View FIGURE 1 A, 2 A); venter with circular corrugations. Legs yellowish-brown with broad black patches. Body length 3.25. Prosoma length 1.29, width (at the middle) 0.85. Opisthosoma length 1.96, width (at the middle) 1.77. Eyes diameter: AME 0.07. ALE 0.07. PME 0.06. PLE 0.07. Eye interdistance: AME –AME 0.07. AME –ALE 0.19. AME –PME 0.07. PME –PME 0.05. PME –PLE 0.24. Clypeus height at AMEs 0.11, at ALEs 0.11. Measurements of palp and legs: Palp 1.27 [0.29, 0.17, 0.15, 0.66], I 2.87 [0.91, 0.45, 0.58, 0.53, 0.40], II 2.57 [0.84, 0.41, 0.47, 0.46, 0.39], III 1.74 [0.56, 0.27, 0.30, 0.30, 0.31], IV 2.6 [0.89, 0.35, 0.51, 0.49, 0.36]. Leg formula: 1423. Pedipalp ( Figs. 1View FIGURE 1 C –D, 2 C –D): Palpal segments yellowish-brown; cymbium brown. Tibia with a disto-prolateral finger-like extension directed at 10 o’clock position ( Figs. 1View FIGURE 1 C, 2 C); RTA with broad base and narrow tip, base of RTA directed at 4 o’clock, but its tip at 3 o’clock ( Fig. 2View FIGURE 2 D). Cymbium with a baso-retrolateral extension ( Figs. 1View FIGURE 1 D, 2 D). Embolus with slightly broad base and narrow, blunt tip, directed at 3 o’clock position ( Figs. 1View FIGURE 1 C, 2 C). Conductor with a disto-median, filiform process, with distinct ridges ( Figs. 1View FIGURE 1 C, 2 C). Paramedian apophysis nearly reniform, with less sclerotized basal part, lying in close contact with the basal part of embolus ( Figs. 1View FIGURE 1 C, 2 C). Median apophysis serrated ( Figs. 1View FIGURE 1 C –D, 2 C –D).

Female (Pathiramanal Island, Figs. 1View FIGURE 1 B, 2 B): Prosoma brown (dark-black in live specimen). Sternum with a large, median dirty-white patch. Opisthosoma hexagonal, white, provided posteriorly and laterally with paired, thick spines; lateral pairs closely packed, while posterior pair widely separated ( Figs. 1View FIGURE 1 B, 2 B); dorsum provided with three transverse black bands and four rows of large sigillae; venter black with irregularly scattered white patches, transverse corrugations and a large conical tubercle between epigynum and anal tubercle. Legs yellowish-brown with black patches. Body length 7.55 (excluding the posterior spines). Prosoma length 2.65, width (at the middle) 3.19. Opisthosoma length 4.90, width (at the middle) 10.65 (excluding the lateral spines). Eyes diameter: AME 0.05 ALE 0.06. PME 0.05. PLE 0.06. Eye interdistance: AME –AME 0.08. AME –ALE 1.24. AME –PME 0.21. PME –PME 0.10. PME –PLE 1.25. Clypeus height at AMEs 0.22, at ALEs 0.24. Measurements of palp and legs: Palp 3.95 [1.22, 0.62, 0.83, 1.28], I 8.62 [2.70, 1.37, 1.77, 1.78, 1.00], II 8.15 [2.72, 1.29, 1.53, 1.65, 0.96], III 6.21 [2.03, 0.94, 1.15, 1.17, 0.92], IV 9.85 [3.25, 1.28, 2.07, 2.12, 1.13]. Leg formula: 4123. Epigynum ( Figs. 1View FIGURE 1 E –F, 2 E –F): Posterior borderline folded slightly in front, with a median depression to form M-shape ( Fig. 2View FIGURE 2 E). Scapus short, squarish, as long as the lateral lobes ( Fig. 2View FIGURE 2 E). Spermathecal head globular with short, wide copulatory duct ( Figs. 1View FIGURE 1 F, 2 F).

Variation. Female body length (n = 3) 7.55–8.02.

Natural history. Both males and females of G. geminata  construct orb-webs, preferably in open places among bushes at a height of 0.5 m to 2 m above from the ground level. The web is a highly geometrical orb-web oriented obliquely to the ground level. The adult male spider (described here) was collected from the web of one of the females. Distribution. Known only from India and Sri Lanka (World Spider Catalog 2014).

ADSH

Arachnology Division, Sacred Heart College

Kingdom

Animalia

Phylum

Arthropoda

Class

Arachnida

Order

Araneae

Family

Araneidae

Genus

Gasteracantha

Loc

Gasteracantha geminata ( Fabricius, 1798 )

Sankaran, Pradeep M., Jobi, Malamel J. & Sebastian, Pothalil A. 2015
2015
Loc

Gasteracantha geminata

Kim 2013: 175
Tikader 1982: 53
Dahl 1914: 267
Pocock 1900: 233
Simon 1895: 836
1900
Loc

Gasteracantha rimata

Cambridge 1879: 282
1879
Loc

Aranea geminata

Fabricius 1798: 292
Loc

Gasteracantha geminata

Koch 1837: 16
Loc

Plectana geminata

Walckenaer 1841: 158
Loc

Gasteracantha connata

Butler 1873: 168