NANOMETINAE FORSTER & FORSTER, 1999

Álvarez-Padilla, Fernando & Hormiga, Gustavo, 2011, Morphological and phylogenetic atlas of the orb-weaving spider family Tetragnathidae (Araneae: Araneoidea), Zoological Journal of the Linnean Society 162 (4), pp. 713-879 : 802-803

NANOMETINAE FORSTER & FORSTER, 1999

NEW RANK ( FIGS 4F , 71–76 , 87–91 , 96–99 )

Type genus: Nanometa Simon, 1908 . This family name was first proposed by Forster & Forster (1999: 166) at the family rank, but it has never been formally diagnosed.

Diagnosis: Nanometines can be differentiated from other tetragnathids by the following combination of characters: female cheliceral denticles present (84-1: Figs 73C , 88D ), absence of trichobothria on femur IV ( Fig. 73F ) and the remaining femora, female genital openings often plugged with amorphous material (132-3: Figs 74A , 98B ), male palpal patella without macrosetae (180-0: Figs 73D , 97H ), conductor originating on the centre of the tegulum (55-0), solid, uniform degree of sclerotization between tegulum and conductor (59-0); and tubular embolus shape (67-0) ( Figs 75E , 76A–C , 90C , 91A ). These six characters also represent the morphological synapomorphies supporting this lineage obtained by the total evidence analysis of Dimitrov & Hormiga (2011), in which they are labelled as ‘ Nanometa clade’ (see also Álvarez- Padilla et al., 2009). Additional diagnostic characters of nanometines are the female copulatory ducts longer than the spermathecae length (146-2; Figs 74B , 89D , 98D ), shorter in Pinkfloydia Dimitrov & Hormiga, 2011 : figs 8G, H, 15F); the presence of a cymbium ectobasal process (26-1); and having the cymbium ectomedian process more than half the cymbial width (30-1: Figs 75A , 90A, C , 99D ). The characteristic branched tracheal system of many nanometines (such as Nanometa and ‘ Orsinome ’ sarasini ; see Forster & Forster, 1999: 166) is not found in Pinkfloydia , which has its median tracheal trunks confined to the abdomen and not branched ( Dimitrov & Hormiga, 2011).

Taxonomic and natural history: Forster & Forster (1999) were the first to recognize this group endemic to Australasia as ‘Nanometidae’ and discussed some interesting aspects of nanometine anatomy such as the presence of an stridulatory organ on the booklung covers of males opposite to a row of denticles on the IV coxa ( Figs 71A, B , 73E ). They also included in their ‘Nanometidae’ the monotypic genus Eryciniolia Strand, 1912 and Orsinome lagenifera ( Urquhart, 1888) . There are many species to be described in Nanometinae , some which are new (e.g. Dimitrov & Hormiga, 2011) but others are misplaced, such as the case of ‘ Orsinome ’ sarasini ( Figs 143A, B , 144 ), which is not congeneric with the type species of Orsinome and belongs in the Nanometinae . At the present time Nanometinae includes the genera Nanometa and Pinkfloydia . The monophyly of Nanometinae has been tested in recent phylogenetic analyses that also included molecular data and the group is relatively well supported ( Álvarez-Padilla et al., 2009; Dimitrov & Hormiga, 2011).

Figures

Figure 4. Webs of tetragnathids: A, Mesida argentiopunctata from Noosa National Park, Australia (37 cm horizontal) (Leuc004b). B, Metabus ebanoverde from Ébano Verde Natural Reserve, Dominican Republic (72 cm horizontal) (DSCN7567). C, Meta menardi from Zealand, Denmark (15 cm horizontal, photograph by Nikolaj Scharff). D, Metleucauge eldorado from California, USA (40 cm horizontal). E, Mollemeta edwardsi from Puyehue National Park, Chile (50 cm horizontal). F, Nanometa sp. from Lamington National Park, Australia (18 cm horizontal) (DSCN0492). Photographs (D) and (E) by Gustavo Hormiga.

Figure 71. Nanometinae sp. abdomen: A, female booklung cuticle. B, male booklung cuticle. C, tracheal system dorsal view. D, tracheal spiracle posterior view. E, median tracheae ramifications. F, epiandrous fusules. All images from SEMFAP049.

Figure 72. Nanometinae sp. abdomen and chelicerae: A, posterior median spinnerets. B, posterior lateral spinnerets. C, anterior lateral spinnerets. D, female chelicera. E, male chelicera. All images from SEMFAP049.

Figure 73. Nanometinae sp. cephalothorax and chelicerae: A, female tangential view. B, female dorsal view. C, cheliceral denticles. D, male tangential view. E, coxa dorsal surface. F, femur IV ectal view. G, female cephalothorax ventral view and sternum. All images from SEMFAP049.

Figure 74. Nanometinae sp. epigynum: A, ventral view. D, dorsal view. C and D, accessory glands. E, lateral view. F, anterior view. All images from SEMFAP049.

Figure 75. Nanometinae sp. male pedipalp: A, dorsal view. B, apical. C, ventral view. D and E, ectal view. F, mesal view. All images from SEMFAP049.

Figure 76. Nanometinae sp. genital anatomy illustrations: A–C male pedipalp expanded. D, sperm duct. E, cleared epigynum ventral view.

Figure 87. Nanometa sp. abdomen: A, male book cuticle. B, abdomen tracheal system dorsal view. C, tracheal spiracle posterior view. D, median tracheae ramifications. E, epiandrous fusules. F, lateral trachea tip. G, male posterior lateral spinnerets. H, female spinnerets. All images from SEMFAP048.

Figure 88. Nanometa sp. cephalothorax: A, female tangential view. B, female dorsal view. C, female ventral view. D, female cheliceral denticles. E, male chelicera. F, male IV coxae dorsal view. All images from SEMFAP048.

Figure 89. Nanometa sp. epigynum: A, ventral view. B, dorsal view. C, accessory glands. D, spermatheca and copulatory ducts. All images from SEMFAP048.

Figure 90. Nanometa sp. male pedipalp: A, dorsal view. B, apical view. C, ventral view. D, ectal view. E, cymbial ectobasal process. F, mesal view. All images from SEMFAP048.

Figure 91. Nanometa sp. and ‘Orsinome’ sarasini genital anatomy illustrations: A, Nanometa sp. palp expanded. B, ‘Orsinome’ sarasini, pedipalp expanded. C, Nanometa sp. cleared epigynum ventral view. D, ‘Orsinome’ sarasini cleared epigynum ventral view.

Figure 96. ‘Orsinome’ sarasini abdomen: A, male booklung cuticle. B, anterior lateral spinnerets. C, posterior lateral spinnerets. D, tracheal spiracle posterior view. E, posterior median spinnerets. F, median tracheae tips. G, epiandrous fusules. All images from SEMFAP050.

Figure 97. ‘Orsinome’ sarasini cephalothorax: A, male dorsal view. B, female dorsal view. C, female chelicera. D, male chelicera. E, female tangential view. F, male coxa IV dorsal view. G, female sternum. H, male tangential view. All images from SEMFAP050).

Figure 98. ‘Orsinome’ sarasini epigynum: A, lateral view. B, ventral view. C, spermatheca. D, dorsal view. E, accessory glands. F, lateral view. All images from SEMFAP050.

Figure 99. ‘Orsinome’ sarasini male pedipalp: A, mesal view. B, apical view. C, ventral view. D, dorsal view. E, ectal view. F, cymbial ectobasal process. All images from SEMFAP050.

Figure 143. Strict consensus trees of parsimony analyses of the morphological and behavioural data set presented in Appendix 2: A, strict consensus cladogram of the five cladograms of minimal length obtained under equal weights of 1033 steps (consistency index = 26, retention index = 58); the consensus tree is ten steps longer. Bremer support values are given under the nodes. B, strict consensus of 11 optimal cladograms obtained with implied weights at concavities 1 to 100; the consensus tree is 101 steps longer than the equal weighted optimal cladograms. Symmetric resampling support values above 51% are given under each node. See text for additional details.

Figure 144. Preferred optimal cladogram from the study of Álvarez-Padilla et al. (2009). This tree is based on a combined analysis, using direct optimization methods, of multigene DNA sequences and the morphological and behavioural data set presented in Appendix 2. The single most parsimonious tree was 54 536 steps when all the data were analysed simultaneously. Numbers under each node correspond to the node numbers in Table 1 where all support values are plotted and the synapomorphies mapped.