Trogloneta, SIMON 1922

Lopardo, Lara & Hormiga, Gustavo, 2015, Out of the twilight zone: phylogeny and evolutionary morphology of the orb-weaving spider family Mysmenidae, with a focus on spinneret spigot morphology in symphytognathoids (Araneae, Araneoidea), Zoological Journal of the Linnean Society 173 (3), pp. 527-786 : 778-779

TROGLONETA SIMON 1922

( FIGS 63 , 64 , 65B–H , 66–68 , 128F , 131E, F , 142C : CLADE C192)

Trogloneta Simon, 1922: 200 ( Troglonata , lapsus calami). Simon, 1926: 313. Fage, 1931: 143. Gertsch, 1960a: 12. Levi & Levi, 1962: 64. Brignoli, 1970: 1409. Thaler, 1975: 284. Wunderlich, 1980b: 267. Brignoli, 1983: 380. Wunderlich, 1987: 139–140. Heimer & Nentwig, 1991: 306. Breuss, 2001: 187. Brescovit & Lopardo, 2008: 94–104.

Parogulnius Archer, 1953: 20 . Gertsch, 1960a: 10 (synonymized with Trogloneta ). Brignoli, 1970: 1410 (rejected synonymy, transfer to Theridiosomatidae ). Coddington, 1986a: 6 (placed in Theridiosomatidae as incertae sedis). Lopardo & Coddington, 2005: 176 (suggested placement within Mysmenidae , no formal taxonomic action).

Type species

Trogloneta granulum Simon 1922 by original designation, type material in MNHN, examined.

Familial placement and composition

Transferred to Symphytognathidae from Theridiidae by Gertsch (1960a), and to Mysmenidae from Symphytognathidae by Forster & Platnick (1977). In the working phylogenetic hypothesis ( Fig. 161B ), Trogloneta is sister to the clade comprising Maymena plus Mysmenopsinae . Currently, Trogloneta includes nine described species (Platnick, 2014), and it is here represented by two described plus four undescribed species (the latter species have been scored for molecular data only): T. granulum , T. cantareira , Trogloneta sp-Rix-AUST, Trogloneta -MYSM-022- ARG, Trogloneta -MYSM-024- CHILE, and Trogloneta - MYSM-025- CHILE).

Monophyly

Morphological synapomorphies of Trogloneta include: a third additional anterior field on ALS ( Figs 64C , 66F ); minute colulus ( Figs 64D , 67F , 68C ); minute AME ( Fig. 67G ); posterior median eyes separated ( Fig. 67H ); triangular labium, not swollen ( Figs 63I , 66H ); uniform coloration on dorsal abdomen, but distinctly lighter ventral abdomen, with whitish extended coloration posteriorly; no abdominal supra-pedicellate nubbins; lateral copulatory ducts–spermathecae junction; two spermstorage compartments per spermatheca ( Fig. 128F ); accessory glands on vulva ( Fig. 64A ); female distal ventral sclerotized spot only on femur I; males with all eyes on tubercle ( Figs 63G, H , 66A ); carapace height dimorphism (i.e. male carapace higher than female, compare Figs 63G and 64E ); bifid embolus ( Figs 63E , 66E ); tegular groove acting as conductor ( Figs 63E , 66C ); no switchbacks I and II on the spermatic duct ( Fig. 131E, F ); a flat and blunt primary cymbial conductor with a particular half circle shape ( Fig. 63B, C ), and particular cymbial shape, flat and tapering ( Fig. 63C ), with basal paracymbium ( Fig. 63A ), and with internal cymbial tarsal organ ( Fig. 63B, F ). Ambiguously optimized synapomorphies for Trogloneta include: anterior reduced booklungs ( Fig. 67C ); posterior respiratory system, with single median apodemal structure ( Fig. 64B ); epigynal area elevated ventrally and smooth uniform proximal copulatory ducts of increased diameter ( Figs 64A , 128F ); males with sclerotized femoral spot on femur I; shorter, but stout and straight setae comprising the tarsal prolateral row on leg I ( Figs 65D , 68A ); and tegular conductor neither with a proximal groove nor associated with embolus, and with a surface covered with small ridges ( Fig. 63A, B, D ). Trogloneta is also supported by 160 molecular synapomorphies.

Diagnosis

Trogloneta differs from all other mysmenid genera by the presence of a third additional anterior field on ALS; minute colulus (although it has been described as ‘large’ on the type species T. granulum by Thaler, 1975: but see figs 67F, 68C); minute AME; PME separated; posterior respiratory system with single median apodemal structure; triangular labium; two sperm-storage compartments per spermatheca; males with all eyes on tubercle; a basal paracymbium; a particular cymbial shape, flat and tapering, with a flat and blunt primary cymbial conductor with a particular half-circle shape; tegular conductor neither with a proximal groove nor associated with embolus, and with a surface covered with small ridges; and no switchbacks I and II on the spermatic duct. Although shared with a few other mysmenids, the following combination of features is unique for Trogloneta : distinctly lighter ventral abdomen, with whitish extended coloration posteriorly; carapace height dimorphism (male carapace higher than female); anterior booklungs reduced; females with distal ventral sclerotized spot only on femur I, epigynal area elevated ventrally, accessory glands on vulva, and smooth uniform proximal copulatory ducts of increased diameter; males with sclerotized femoral spot on femur I; shorter, but stout and straight setae comprising the tarsal prolateral row on leg I; bifid embolus; tegular groove acting as conductor; and internal cymbial tarsal organ. The taxonomic history and previous diagnostic features for Trogloneta have recently been reviewed by Brescovit & Lopardo (2008). Their proposed combination of features diagnostic for the genus is in agreement with those proposed in our study.

Figures

Figure 63. Trogloneta cantareira (Mysmenidae), male. A–F, right palp, inverted; A, retrolateral view; B, prolateral view; C, dorsal view; D, ventral–retrolateral view; E, ventral view; F, detail of embolic base and primary cymbial conductor. G, prosoma, lateral view; H, ocular area, frontal view; I, mouthparts, lateral–ventral view. See Appendix 3 for the list of abbreviations.

Figure 64. Trogloneta cantareira (Mysmenidae), female: A, digested abdomen, detail of vulva; B, same, detail of posterior respiratory system; C, right anterior lateral spinneret; D, abdomen, detail of colulus and posterior respiratory spiracle; E, prosoma, lateral view; F, same, anterodorsal view; G, left palpal tibia, dorsal view; H, sternal cuticular pattern; I, carapace dorsal cuticular pattern, detail from panel F. See Appendix 3 for the list of abbreviations.

Figure 65. A, Mysmena (= Tamasesia) rotunda (Mysmenidae), female syntype, left posterior lateral spinneret. B–H, Trogloneta cantareira (Mysmenidae). B, female left leg I; C–F, male left leg I; G, H, female left leg IV. B, femur, patella and tibia; C, metatarsus, dorsal view; D, tarsus, prolateral view; E, proximal metatarsal cuticular pattern, dorsal view; F, claws, prolateral view; G, tarsus, retrolateral view; H, metatarsus, retrolateral view. See Appendix 3 for the list of abbreviations.

Figure 66. Trogloneta granulum (Mysmenidae), male. A, prosoma, lateral view. B–E, left palp; B, retrolateral view; C, prolateral view; D, prolateral–dorsal view; E, embolus. F, anterior lateral spinnerets; G, mouthparts, lateral view; H, labium, ventral view. See Appendix 3 for the list of abbreviations.

Figure 67. Trogloneta granulum (Mysmenidae), female. A, epigynum, ventral view; B, same, posterior view; C, digested abdomen, anterior respiratory system and vulva; D, left posterior spinnerets; E, booklung cover; F, abdomen, detail of colulus and posterior spiracle, ventral view; G, ocular area, frontal view; H, same, dorsal view. See Appendix 3 for the list of abbreviations.

Figure 68. Trogloneta granulum (Mysmenidae), male. A, left tarsus I, prolateral view; B, left metatarsus I, prolateral view; C, abdomen, detail of colulus, posterior spiracle and spinnerets, ventral view; D, left tibia III, prolateral view.

Figure 128. Mysmenidae female genitalia, cleared: A, Isela okuncana, dorsal view; B, Maymena mayana, dorsal view; C, Kilifina-MYSM-002-KENYA (Isela sp.), from Kwale, Kenya, dorsal view; D, Maymena ambita, ventral view; E, Maymena rica, dorsal view; F, Trogloneta granulum, ventral view; G, Mysmenopsis dipluramigo, dorsal view. See Appendix 3 for the list of abbreviations.

Figure 131. Mysmenidae male left palp (unless otherwise stated), cleared: A, Mysmenopsis penai, retrolateral view, right palp, inverted; B, Mysmenopsis dipluramigo, retrolateral view; C, Mysmenopsis cidrelicola, presumably paralectotype, retrolateral view, right palp, inverted; D, Kilifina-MYSM-002-KENYA (Isela sp.), from Kwale, Kenya, ventral view, right palp, inverted; E, Trogloneta granulum, ventral view; F, Trogloneta cantareira, ventral view; G, Kilifina-MYSM-002- KENYA (Isela sp.), from Kwale, Kenya, dorsal view, right palp, inverted; H, Isela okuncana, ventral view; I, Maymena ambita, ventral view; J, Maymena mayana, ventral view. See Appendix 3 for the list of abbreviations.

Figure 142. Composite images of Mysmenidae species: Mysmeninae and Trogloneta. A, B, Microdipoena nyungwe; A, male, lateral view; B, female, ventral view. C, Trogloneta granulum, female, ventral view. D, Mysmena (= Calodipoena) incredula, female, lateral view, inverted. E, Mysmena (= Calodipoena) mootae, female holotype, dorsal view. F, Mysmena (= Calomyspoena) santacruzi, female paratype, dorsal view. G–I, Mysmena (= Itapua) tembei; G, male holotype, lateral view, inverted; H, male holotype, frontal view; I, female paratype, frontal view. J–L, Mysmena (= Kekenboschiella) awari, male paratype; J, lateral view; K, dorsal view; L, ventral view. M, N, Mysmeniola spinifera, male holotype; M, lateral view; N, ventral view. O, Brasilionata arborense, male holotype, dorsal view, abdomen detached. Scale bars: 0.5 mm.

Figure 161. Hypothesis of relationships within Mysmenidae, taken from the results of the combined analysis from Lopardo et al. (2011) (see Fig. 160). New taxonomic (i.e. generic) status as proposed in our study is assigned to each representative; new combinations are emphasized in bold. Unambiguous morphological character optimizations are shown for every branch in the tree. Numbers below each node indicate node numbers. Empty and filled boxes represent homoplasious and non-homoplasious transformations, respectively. Major clades representing taxonomic decisions discussed in the text are highlighted in grey boxes.