Tetragnatha Latreille, 1804
|
publication ID |
https://doi.org/10.26515/rzsi/v124/i2/2024/168214 |
|
persistent identifier |
https://treatment.plazi.org/id/03E087B7-FFE5-FFF0-FC8B-B6AAFCFFF7B6 |
|
treatment provided by |
Felipe |
|
scientific name |
Tetragnatha Latreille, 1804 |
| status |
|
Tetragnatha Latreille, 1804 View in CoL
Type species: Tetragnatha extensa (Linnaeus 1758) ( Figures 1-6 View Figure 1 View Figure 2 View Figure 3 )
Type material: Holotype: Female: China, Hainan Island, Danzhou , 20°01’11”N, 110°20’54”E, 4-IV-2012, coll. A. T. Barrion et al. (not examined) GoogleMaps
Material examined: 5 males, 8 females (CATE11840270), 2 males (ZSI/WGRC/I.R.-INV.27362): India, Kerala, Thrissur district, Pullu Kole wetlands, 10°27’27.04”N, 76°09’08.24”E, 27-xi-2021, coll. Anju K. Baby, E. H. Vishnudas and A. V. Sudhikumar. GoogleMaps
Diagnosis: Tetragnatha squamata is one of the smallest species in the genus Tetragnatha ( Yin et al., 2012) . It resembles T. vermiformis Emerton, 1884 ( Zhu et al., 2003). Males of both species have elongated bodies, and chelicerae with pointed ʻaʼ and small IC, but differ from T. vermiformis in having small U2 (which is large, pointed and represented as ʻTʼ in T. vermiformis ), absence of AX1 and fang with small OC, palp with enlarged tegulum and moderate-sized conductor.
Females of both species have similar stout chelicerae with all teeth pointed, Gu not much closer to the fang base and fang without cusps. But T. squamata differs in having abdomen ovoid, chelicerae with similar sized Gu and U2, Gl and L2 closely placed, long and broad genital fold, and internal genitalia with a pair of spermathecae with triangular-shaped central membranous sacs (whereas two pairs of spermathecae in T. vermiformis and lack a central membranous sac).
Description: Male ( Figures 2A–C View Figure 2 , 3A–F View Figure 3 , 4A–D). Body length 4.87. Carapace length 1.73, width (at the middle)
1.16. Abdomen length 3.14, width 1.15. Ocular area length 0.22, width (at the middle) 0.25. Eye diameters: AME 0.12, ALE 0.08, PME 0.09, PLE 0.09. Clypeus height
0.16. Length of chelicera 1.38, width 0.45. Palp and leg measurements: palp 5.13 [2.42, 0.13, 0.29, 2.32], leg I 13.23 [3.62, 0.62, 4.50, 3.82, 0.67], II 9.73 [2.79, 0.56,
3.26, 2.70, 0.42], III 5.08 [0.93, 0.41, 1.45, 1.70, 0.59], IV
9.33 [2.62, 0.50, 2.76, 2.83, 0.62]. Leg formula: 1243. Leg spination: femur I 1000, II–III 1010, IV 0010; patella I Anju et al., 0100, II spineless, III–IV 0100; tibia I–II 2022, III 1100, IV 2020; metatarsus I–II 1110, III–IV spineless; tarsus I–IV spineless. The colouration of the live specimen: carapace pale green; abdomen yellowish green with red markings on the anterior and posterior on the dorsum along with silvery spots ( Figure 1A View Figure 1 ). Colouration in alcohol: carapace brownish yellow, anteriorly narrowed, medially broad with distinct fovea and dark coloured cephalic furrow ( Figure 2A View Figure 2 ). Two rows of eyes strongly recurved; ALEs small; clypeus yellow. Chelicerae long, slender, brownish yellow with 6 promarginal and 5 retromarginal teeth; ʻaʼ extremely elongated, tapering, directed upward; Gu stout, not much closer to the fang base; U2 small, pointed, set apart by a large gap between from Gu and U3, U3 larger than U2 followed by three teeth ( Figures 4A, C); AX1 absent; Gl large, bulky, considerably curved at the distal end; L2 closer to Gl and bends at the middle towards the upper side; L3 straight, directed upward, slightly separated from L2 followed by two teeth ( Figures 4B, D). Fang strongly geniculate with small OC and IC, constricted at the middle, distal end inserted between two rows of teeth. Labium yellowish brown, maxillae yellow and elongated; sternum yellow and heart-shaped. The abdomen is cylindrical, elongated, yellow, covered with brownish yellow markings in the middle along with golden yellow spots, laterally with silvery spots; venter with dark grey on the middle and silvery spots on each sides ( Figures 2B, C View Figure 2 ). Legs light yellow. Palpal segments brownish yellow; cymbium long, creamy white with numerous spines; conductor thin, transparent and completely enfolding the embolus. Embolus long, brownish yellow, originated from the middle of the bulb and distally curved towards the mesal side. Paracymbium is thick, nearly transparent, rounded at the tip and a knob at the ectal side ( Figures 3A–F View Figure 3 ).
Female ( Figures 2D–F View Figure 2 , 3G–I View Figure 3 , 4A–D). Body length:
5.27. Carapace length 1.58, width (at the middle) 1.11. Abdomen length 3.69, width (at the middle) 1.59. Ocular area length 0.23, width 0.25. Eye diameters: AME 0.10, ALE 0.04, PME 0.08, PLE 0.08. Clypeus height 0.12. Length of chelicera 0.78, width (at the middle) 0.36. Leg I 13.37 [3.67, 0.55, 4.09, 3.92, 1.14], II 10.29 [2.87, 0.57,
3.04, 2.90, 0.91], III 5.82 [1.78, 0.42, 1.44, 1.62, 0.50], IV 9.49 [2.92, 0.45, 2.62, 2.75, 0.75]. Leg formula: 1243. Leg spination: femur I 1100, II spineless, III 0200, IV 0010; patella I spineless, II–IV 0100; tibia I 2021, II 2010, III 0100, IV 0001; metatarsus I–IV 1000; tarsus I–IV spineless. Colouration of live specimens: Carapace green; abdomen green with red markings on the anterior and posterior on the dorsum along with silvery spots ( Figure 1B View Figure 1 ). Colouration in alcohol: carapace golden yellow, anteriorly narrowed, medially broad, fovea and cephalic furrow not much distinct ( Figure 2A View Figure 2 ). Two rows of eyes strongly recurved; ALEs were small. Clypeus pale yellow. Chelicerae stout, pale straw colour with brownish yellow teeth, six promarginal and five retromarginal teeth; AXu absent, Gu large, straight, pointed with large base; U2 projected upward followed by four teeth equally spaced and arranged in descending series ( Figures 5A, C View Figure 5 ); AX1 absent, Gl large, stout, tapering, distal half bends towards the upper side and slightly separated from fang base; L2 long, slender, positioned closer to Gl; L3 larger than L2 followed by two teeth opposite to U3 and U4; fang brownish yellow and nearly transparent ( Figures 5B, D View Figure 5 ). Labium elongated; sternum pale yellow and heart-shaped ( Figure 2E View Figure 2 ). Abdomen ovoid, brownish yellow markings with golden yellow spots on the dorsal, laterally with silvery spots; venter with black markings on the middle along with silvery spots ( Figures 2E, F View Figure 2 ). Leg I and II are yellowish brown, and III and IV are transparent with brownish-yellow markings. Genital fold long, broad, slightly bulged, sclerotized with a round tip. Internal genitalia with a pair of spermathecae, anteriorly broad with a short base with triangular shaped central membranous sac ( Figures 3G–I View Figure 3 ).
Variation: Males (n = 7): total length, 4 – 5; females (n= 8): total length, 5–6. Males have chelicerae with 6–8 promarginal teeth. These teeth can be represented as U6, U7 and U8.
Natural History: They are nocturnal and construct orb webs between trees, rice plants and other vegetation.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.