Theridium eximius, LINEAGE

Agnarsson, Ingi, 2006, A revision of the New World eximius lineage of Anelosimus (Araneae, Theridiidae) and a phylogenetic analysis using worldwide exemplars, Zoological Journal of the Linnean Society 146 (4), pp. 453-593 : 471

THE EXIMIUS LINEAGE

The eximius lineage occurs only in the New World ( Fig. 63A ) and contains the majority of American species. It includes all the most intensively studied Anelosimus species and is revised below. Eight unambiguous synapomorphies support its monophyly, including: deeply notched cymbial margin (15 -2, Figs 23A, B , 29A , 33A ), translucent cymbial hood (25 -0), an abrupt post-switchback II turn of the sperm duct (30 -1, Fig. 57D–G ), subterminally ridged theridiid tegular apophysis (56 -1, Figs 2B , 42C ), and embolus-distal hematodocha grooves (69 -1, Figs 35B, H, L , 36C , 39B, C ). Five of the seven known social Anelosimus species belong in five subgroups of the eximius group.

Figures

Figure 2. Anelosimus analyticus, male palp. A, dorsal; B, submesal; C, ventral, note the small embolic division b (Eb), and the cymbial hood (upper arrow). In this species the embolic lobe fits snugly under the subconductor (SC); D, ectal; E, apical view of tip, mesal side; F, part of palpal tibia, unusually with four trichobothria (arrows). Scale bars: A–D, 100 µm; E,F, 50 µm.

Figure 23. Anelosimus jucundus, male palp. A, dorsal view; B, mesal; C, submesal, the conspicuous embolus division b ridge (arrow) is a synapomorphy uniting A. jucundus, A. octavius and A. arizona; D, ventral; E, ectal, subcaudal view; F, details of E tip, the small conductor can be detected in the background (arrow). Scale bars: 100 µm.

Figure 29. Anelosimus baeza from Las Caucheras, male palp. A, dorsoapical view; B, mesal; C, submesal, apical view; D, ventral, note a conspicuous ectal tegular process (arrow); E, details of conductor, subconductor and embolus tip, ventral; F, palpal tibia, with three trichobothria (arrows). Scale bars: 100 µm.

Figure 33. Anelosimus puravida, male palp. A, dorsomesal view; B, apical, submesal; C, ventral; D, ectal, tip of palpus; E, apical, tip of palpus; F, details of embolus tip and conductor. Scale bars: 100 µm.

Figure 35. The ‘studiosus group’. A–F, Anelosimus tosum. A, male palp mesal; B, same ventral; C, epigynum; D, internal epigynum dorsal; E, female abdomen dorsal; F, same ectal. G–J, Anelosimus oritoyacu. G, male palp mesal; H, same ventral; I, epigynum; J, internal epigynum dorsal. K–Q, Anelosimus tungurahua. K, male palp mesal; L, same ventral; M, male habitus ectal; N, same, dorsal; O, female abdomen ectal; P, epigynum; Q, internal epigynum dorsal.

Figure 36. Anelosimus tosum, male palp. A, mesal view; B, submesal; C, ventral; D, ectal; E, apicoventral; F, details of embolus tip and conductor. Scale bars: 100 µm.

Figure 39. Anelosimus oritoyacu Ecuador, male palp. A, mesal view; B, submesal; C, ventral; D, ectal; E, details of distal sclerites, ventral; F, mesal view of distal sclerites. Scale bars: 100 µm.

Figure 42. Anelosimus tungurahua male palp. A, dorsal view; B, mesal; C, apical; D, ventral; E, ectal; F, details of embolus tip. Scale bars: A–E, 100 µm; F, 10 µm.

Figure 57. Characters III. A, Anelosimus nelsoni, note a finger-shaped lower branch of the theridiid tegular apophysis hook (arrow); B, Anelosimus nigrescens, note a blade-like lower branch of the theridiid tegular apophysis hook (arrow); C, Anelosimus ethicus, with a small, barely separate embolic division b (arrow); D, Anelosimus baeza male palp, ventral view, showing the sperm duct trajectory in the tegulum relative to position of sclerites; E, Anelosimus eximius, a schematic view of the sperm duct trajectory from ectal view (view as in G), F, Anelosimus eximius from above; G, Anelosimus baeza ectal view, showing switchbacks I and II.

Figure 63. A, Distribution of the Anelosimus lineage; B, distribution of A. domingo, A. dubiosus and A. jabaquara; C, distribution of A. oritoyacu, A. guacamayos, A. fraternus, A. pantanal and A. puravida.