Metleucauge, LEVI 1980
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publication ID |
https://doi.org/ 10.1111/j.1096-3642.2011.00692.x |
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persistent identifier |
https://treatment.plazi.org/id/7D5E87AD-C02C-554E-FF74-4C7ED161F898 |
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treatment provided by |
Valdenar |
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scientific name |
Metleucauge |
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METLEUCAUGE LEVI 1980 View in CoL View at ENA ( FIGS 4D View Figure 4 , 77–81 View Figure 77 View Figure 78 View Figure 79 View Figure 80 View Figure 81 )
Type species: Metleucauge eldorado Levi 1980 . The holotype of M. eldorado is a female specimen from California ( USA), deposited at the Museum of Comparative Zoology , Harvard University (not examined).
Diagnosis: Metleucauge species can be distinguished from all other tetragnathid genera by the following combination of characters: cephalic fovea of both sexes resembling two deep pits ( Fig. 78A View Figure 78 ); femora without trichobothria ( Fig. 78E View Figure 78 ); epigynum flat with two deep atria ( Fig. 79A, B View Figure 79 ); spermathecae weakly sclerotized ( Figs 79C, D View Figure 79 , 81D View Figure 81 ); ( Fig. 78G, H View Figure 78 ); male palpal trochanter with a large distal apophysis, palpal femora and tibia longer than four times its width, almost half the carapace length ( Fig. 78F View Figure 78 ); cymbial dorsobasal process and cymbial ectomedian process present ( Fig. 80B, E View Figure 80 ); and conductor subdivided ( Fig. 81A, B View Figure 81 ).
Description: Female: body length c. 11.0 mm. Ocular area lower than carapace lateral margins ( Fig. 78C View Figure 78 ). Labium trapezoidal, wider than long and rebordered. Sternum longer than wide ( Fig. 78B View Figure 78 ). Anterior surface of chelicerae smooth; boss present ( Fig. 78C, G View Figure 78 ). Secondary eyes with canoe-shaped tapetum ( Levi, 1980: figs 139, 140). Eyes subequal in size, lateral eyes slightly smaller, juxtaposed and on a tubercle. Clypeus c. 1.5 times the AME diameter. Booklung cuticle smooth ( Fig. 77A View Figure 77 ). Tracheal spiracle near the spinnerets, without accessory glands ( Fig. 77D View Figure 77 ). Median tracheae not ramified, tips leaf-shaped ( Fig. 77C, F View Figure 77 ). ALS with an extensive field of piriform spigots ( Fig. 77B View Figure 77 ). PMS with five aciniform spigots between the cylindrical and minor ampullate silk gland spigots but without any aciniform spigots over the anterior surface ( Fig. 77G View Figure 77 ). PLS with c. 25 aciniform spigots arranged in roughly parallel lines; distal end of aggregate spigots embracing tip of flagelliform spigot ( Fig. 77E View Figure 77 ). Epigynal plate flat, copulatory openings ventrally orientaed. Spermathecae walls weakly sclerotized ( Fig. 79A–D View Figure 79 ). Copulatory and fertilization ducts shorter than the spermatheca length and cuticle well sclerotized. Fertilization ducts curved, but not coiling around the copulatory ducts. Accessory glands evenly distributed over the spermathecae, with gland openings arranged in groups ( Fig. 79C, D View Figure 79 ).
Male: size and somatic morphology similar to that of the female, except the chelicerae are longer and their anterior cuticle is rugose ( Fig. 78D, H, F View Figure 78 ). PLS triplet reduced to nubbins. Epiandrous plate flat, fusules arranged in an irregular line of clusters, fusules not immersed in pits ( Fig. 77F View Figure 77 ). Palpal patella with one macroseta ( Fig. 78D View Figure 78 ). Paracymbium rectangular, with a basal apophysis, and considerably shorter than the cymbium length ( Fig. 80B View Figure 80 ). Tegulum roughly oval, with an ectal depression produced by the displaced subtegulum ( Fig. 80A View Figure 80 ). Both conductor parts are well sclerotized; one presents a translucent membranous process ( Fig. 81A, B View Figure 81 ). Conductor attachment to tegulum and between its two parts membranous. Embolus base rectangular, longer than wide; embolus roughly the same length as its base, well sclerotized ( Fig. 81C View Figure 81 ). Sperm duct path with fewer than three coils ( Fig. 81C View Figure 81 ).
Natural history: There are seven described species of Metleucauge , with a geographical distribution on both sides of the Pacific ( Levi, 1980; Tanikawa, 1992; Zhu et al., 2003). These spiders build horizontal webs with open hubs, fewer than ten radii and spirals ( Fig. 4D View Figure 4 ). Their webs are spun between rocks or near streams ( Levi, 1980; G. Hormiga, pers. observ.). Little is known about the biology of Metleucauge species , but a
784 F. ÁLVAREZ-PADILLA and G. HORMIGA pioneering study by Yoshida (1989) documented and compared the feeding behaviours and prey composition for three Japanese species.
Taxonomy: Both the Asian and North American species of Metleucauge have been studied relatively recently ( Levi, 1980; Tanikawa, 1992; Tanikawa & Chang, 1997); however the monophyly of this genus remains untested. Our diagnosis and description are based on M. eldorado specimens and the illustrations of the species described by Tanikawa (1992). The specimens that we coded for the phylogenetic analysis belong to M. eldorado . Tanikawa’s (2001) phylogenetic analysis proposed Metleucauge chikunii Tanikawa, 1992 as sister to a clade formed by a large sample of leucaugines. Support for Tanikawa’s hypothesis was provided by three synapomorphies: presence of cymbial processes other than the paracymbium, seminal receptacles of the female not sclerotized, and a deep thoracic groove ( Tanikawa, 2001; Fig. 8B View Figure 8 ). Both our data sets recovered Metleucauge as sister to a clade that includes Metabus , Orsinome , Tylorida , Mesida , Opadometa , and Leucauge ( Figs 143A, B View Figure 143 , 144 View Figure 144 ).
MOLLEMETA ÁLVAREZ- PADILLA, 2007
( FIGS 4E View Figure 4 , 82–86 View Figure 82 View Figure 83 View Figure 84 View Figure 85 View Figure 86 )
Type species: Mollemeta edwardsi ( Simon, 1904) . The holotype of Landana edwardsi is a female from Chile deposited at the Museum National d’Histoire Naturelle , Paris (examined) .
Diagnosis: Mollemeta can be distinguished from other tetragnathids by the following combination of characters: epigynum with a small spherical scape; copulatory openings located in deep curved groves ( Fig. 84A–C View Figure 84 ); cymbial ectobasal process and cymbial ectomedian process present ( Fig. 85C View Figure 85 ); male palpal femora and tibia longer that four times its width, approximately half the carapace length ( Fig. 83E View Figure 83 ); paracymbium cone-shaped, much shorter than the cymbial ectobasal process ( Fig. 85C View Figure 85 ); tegulum reduced to a narrow ring ( Fig. 86A–C View Figure 86 ); membranous conductor ( Fig. 86C View Figure 86 ); and embolus without basal apophyses ( Fig. 85F View Figure 85 ).
Description: Female: body length c. 10.0 mm. Thoracic fovea transverse and deep ( Fig. 83A View Figure 83 ). Ocular area higher than carapace lateral margins ( Fig. 83G View Figure 83 ). Labium trapezoidal, wider than long and rebordered. Sternum longer than wide ( Fig. 83F View Figure 83 ). Anterior surface of chelicerae smooth; boss present ( Fig. 83C View Figure 83 ). Secondary eyes with canoe-shaped tapetum. Eyes subequal in size, lateral eyes slightly smaller, juxtaposed, and on a tubercle. Clypeus c. 1.5 times the AME diameter. Booklung cuticle grooved ( Fig. 82B View Figure 82 ). Tracheal spiracle near the spinnerets, with accessory glands ( Fig. 82C View Figure 82 ). Median tracheae not ramified, tips leaf-shaped ( Fig. 82D, F View Figure 82 ). ALS piriform spigots bases rounded ( Fig. 82E View Figure 82 ). PMS with three aciniform spigots between the cylindrical and minor ampullate silk gland spigots but without any aciniform spigots over the anterior surface. PLS with c. 25 aciniform spigots arranged in roughly parallel lines; distal end of aggregate spigots embracing tip of flagelliform spigot ( Álvarez-Padilla, 2007: fig. 9L, M). Epigynal plate flat ( Fig. 84A, B View Figure 84 ), copulatory openings posteriorly orientated ( Fig. 86D View Figure 86 ). Spermathecae walls well sclerotized. Copulatory ducts coiled, longer than the spermatheca diameter ( Fig. 84C View Figure 84 ). Fertilization ducts path straight, slightly longer than spermatheca, with well-sclerotized cuticle ( Fig. 84F View Figure 84 ). Accessory glands concentrated over the anterior surface of spermathecae, gland openings arranged in groups ( Fig. 84C–E View Figure 84 ).
Male: size and somatic morphology similar to that of the female ( Fig. 83B, D, E View Figure 83 ). PLS triplet reduced to nubbins ( Álvarez-Padilla, 2007: fig. 9N). Epiandrous plate flat, fusules arranged in an irregular line of fusules clusters, fusules not immersed in pits ( Fig. 82G View Figure 82 ). Palpal patella with one macroseta. Conductor membranous, with rigid edges. Conductortegulum attachment membranous ( Fig. 86A, C View Figure 86 ). Embolus base rectangular and slightly longer than wide; embolus almost as long as the cymbium, well sclerotized ( Figs 85D–F View Figure 85 , 86A View Figure 86 ). Sperm duct path with one loop before reaching fundus ( Fig. 86B View Figure 86 ).
786 F. ÁLVAREZ-PADILLA and G. HORMIGA
Natural history: Mollemeta is a monotypic genus endemic to Chile. These spiders build vertical webs, longer than wide, with a closed hub, with more than 30 spiral turns and radii. The webs of Mollemeta are spun over tree trunks ( Fig. 4E View Figure 4 ).
Taxonomy: The monotypy of this genus was based on the results of a previous cladistic analysis that recovered M. edwardsi as sister to a clade that contains the genera Meta , Metellina , Dolichognatha , Allende , and Chrysometa ( Álvarez-Padilla, 2007) . This sister group relationship was supported by a single synapomorphy, the paracymbium on the base of the cymbial ectobasal process. The morphological + behavioural data set recovered Mollemeta as sister to a clade that includes Metainae, Nanometinae , Tetragnathinae , Chrysometa , and Allende ( Fig. 143A View Figure 143 ); when these data were combined with DNA sequences, Mollemeta was placed as sister to a clade that includes Allende plus Tetragnathinae ( Fig. 144 View Figure 144 ).
| PMS |
Peabody Essex Museum |
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