Glenognatha minuta Banks, 1898

Jimmy Cabra-García & Antonio D. Brescovit, 2016, Revision and phylogenetic analysis of the orb-weaving spider genus Glenognatha Simon, 1887 (Araneae, Tetragnathidae), Zootaxa 4069 (1), pp. 1-183 : 148-153

Glenognatha minuta Banks, 1898

( Figs. 122–125 , 137 )

Glenognatha minuta Banks, 1898: 218 , pl. 15, fig. 15. (male syntype from Baja California, San Jose del Cabo, Mexico, Eisen & Vaslit leg., deposited in MCZ 125505, examined); Hormiga & Döbel 1990: 202, figs. 25–30; Cabra-García et al. 2014: 1029, figs. 1O, 3D, 4F, 6D, 8E, 9N; World Spider Catalog 2015.

Glenognatha centralis Chamberlin, 1925: 216 (male holotype from Panama, R. V. Chamberlin leg., deposited in MCZ 125347 , examined). New synonymy.

Synonymy justification. We examined the male holotype of G. centralis (MCZ 125347) (collected from the stomach of a toad, Bufo sp.) and concluded that the specimen is a subadult male due to the undeveloped male palp sclerites. This conclusion was supported by the finding of a subadult male of G. foxi (from Arizona, AMNH), caught in the molting process, that exhibits a similar palp morphology. After comparison with numerous Glenognatha specimens collected in Panama, we concluded that the morphology of the chelicerae in G. centralis is too similar with the diagnostic morphology found in G. minuta specimens; which is characterized by enlarged Ret2 and Ret3 ( Figs. 123A–C ). The chelicerae orientation and the size of the tegulum, cited as diagnostic for G. centralis by Hormiga & Döbel (1990), are not sufficient to maintain a separate species, as these characters can vary in G. minuta . The unusual shape of the conductor, cited by Hormiga & Döbel (1990) also as a diagnostic character, could be an artifact of the developmental stage of the specimen, the preservation and the digestive process suffered.

Diagnosis. Males of G. minuta can be easily distinguished from all other Glenognatha species by the morphology of the chelicerae, which has a small Ret1 and prominent Ret2 and Ret3, the latter being bigger ( Figs. 123A–C ). Females can be distinguished from all other Glenognatha (except G. emertoni ) by the presence of an anterior cheliceral bulge ( Fig. 123F ); distinguished from G. emertoni by the well-developed spermathecae ( Figs. 125A–D ) and the oval-shaped chelicerae in mesal view ( Fig. 123F ).

Description. Male described by Hormiga & Döbel (1990). Additional data.

Male ( Mexico, Jalisco, Atenquique, AMNH). Habitus as in Figures 122A–D . Carapace brown, darker along furrows. Sternum brown with darker edges. Abdomen oval, dorsally with diffused irregular lateral bands. Silver guanine spots scattered in dorsal and lateral surfaces. Venter pale greyish with scattered silver guanine spots. Tracheal spiracle well-sclerotized. Legs yellow-brownish. Total length 2.37. Cephalothorax 1.10 long, 0.82 wide, 0.62 high. Abdomen 1.30 long, 1.12 wide, 1.07 high. Sternum 0.55 long, 0.60 wide. Eye diameters and interdistances: AME 0.09. ALE 0.07. PME 0.08. PLE 0.08. AME-AME 0.06, AME-ALE 0.08, PME-PME 0.075, PME-PLE 0.075, ALE-PLE 0.01. Clypeus height 1.8. Chelicerae brown. Three promarginal and four retromarginal teeth ( Figs. 123A–C ). Ret2 and Ret3 enlarged ( Fig. 123B–C ). Leg measurements: I: femur 1.37, patella 0.35, tibia 1.25, metatarsus 1.15, tarsus 0.65, total 4.77; II: 1.30, 0.32, 1.25, 1.05, 0.65, 4.57; III: 0.87, 0.25, 0.62, 0.65, 0.40, 2.80; IV: 1.08, 0.25, 0.87, 0.85, 0.47, 3.53. DTS 0.20. DTE 0.50. Palp as in Figures 124E–H . Distal end of the conductor lamina sharp ( Figs. 124B–C , 125H–J ).

Female ( Mexico, Yucatán, AMNH) (Note: the female is here described for the first time). Coloration and general habitus as in male ( Figs. 122E–H ). Abdomen with silver guanine spots arranged in two longitudinal bands that extends to the lateral surfaces. Venter with a median diffused dark band. Total length 2.95. Cephalothorax 1.27 long, 0.92 wide, 0.85 high. Abdomen 1.75 long, 1.57 wide, 1.52 high. Sternum 0.17 long, 0.21 wide. Eye diameters and interdistances: AME 0.09. ALE 0.07. PME 0.08. PLE 0.07. AME-AME 0.07, AME-ALE 0.12, PME-PME 0.13, PME-PLE 0.13, ALE-PLE 0.01. Clypeus height 1.60. Chelicerae brown. Cheliceral basal segment with a mesally oriented distal projection ( Fig. 123D ) and anterior bulge ( Fig. 123F ). Three promarginal and four retromarginal teeth. ( Figs. 123D–F ). Leg measurements: I: femur 1.57, patella 0.40, tibia 1.47, metatarsus 1.27, tarsus 0.67, total 5.40; II: 1.47, 0.47, 1.30, 1.20, 0.65, 5.10; III: 0.95, 0.30, 0.65, 0.70, 0.37, 2.97; IV: 1.37, 0.30, 1.05, 0.80, 0.50, 4.02. DTS 0.08. DTE 0.14. Tracheal system as in Figures 125E–G . Genitalia with well-developed spermathecae ( Figs. 125A–D ). Uterus externus with a median projection ( Figs. 125A, C ).

Variation. Male total length 2.1–2.6 (N = 10; average 2.3), cephalothorax length 1.0–1.2 (N = 10; average 1.1), femur I length 1.3–1.6 (N = 10; average 1.5). Female total length 2.2–3.5 (N = 10; average 2.9), cephalothorax length 1.0–1.7 (N = 10; average 1.32), femur I length 1.2–2.0 (N = 10; average 1.5). In specimens from Panama the cheliceral anterior bulge is more sharpened.

Distribution. Known in Mexico, Guatemala, Costa Rica, Panama, Cuba and Republica Dominicana ( Fig. 137 ).

Additional material examined (N = 30). CUBA: Cienfuegos: Soledad, [Jardín Botánico de Cienfuegos], [22º7´N, 80º20´W], elev. [50m], 1–11.viii.1934, P. J. Darlington leg., 1♂ ( MCZ 125505) .

New records. MEXICO: Jalisco: Atenquique , [19º31´N, 103º26´W], elev. [1168m], 5.xii.1948, H.B. Leech leg., 1♂ ( AMNH) . Nayarit: Ixtlan del Rio , [21º1´N, 104º21´W], elev. [1051m], 22.ix.1962, B. Malkin leg., 1♀ ( AMNH) . Nuevo León: Monterrey , [25º37´N, 100º17´W], elev. [599m], 10.vi.1936, Davis leg., 1♂ ( AMNH) ; Allende: Rio Ramos , [25º16´N, 100º52.13´W], elev. [663m], 18.viii.1954, F. N. Young leg., 1♂ ( AMNH) . San Luis Potosí: Tamazunchale , [21º15´N, 98º47´W], elev. [135m], 25.xi.1938, A. M. & L. I. Davis leg., 1♂ ( AMNH) ; Tamazunchale, arroyo La Chorrera , [21º15´N, 98º47´W], elev. [135m], 28.iii.1937, A. M. & L. I. Davis leg., 1♂ ( AMNH) ; 10 mi. N.E. Xilitla , 21º27´N, 98º55´W, elev. [132m], 19.iv.1963, W. J. Gertsch & W. Ivie leg., 2♂ 1 immature ( AMNH) . Sinaloa: Piaxtla ( River ), 23º50´N, 106º40´W, elev. [33m], 16.v.1963, W. J. Gertsch & W. Ivie leg., 1 immature ( AMNH) . Sonora: Hermosillo , [29º5´N, 110º56´W], elev. [235m], 9–16.vii.1953, B. Malkin leg., 1♀ ( AMNH) . Yucatán: Chichen Itza, Cenote Stolc ., [20º40´N, 88º34´W], elev. [35m], 10.vii.1948, C. & M. Goodnight leg., 1♀ ( AMNH) ; 26.v.1980, J. Coddington leg., 3♀ 1♂ ( USNM) ; 1♀ ( USNM) . GUATEMALA: Petén: Tikal , [17º12´N, 89º37´W], elev. [312m], 1931, Dice & Bartlett leg., 1♀ ( MCZ 125478 ) . REPUBLICA DOMINICANA: La Romana: Guaymate (14 Km N), [18º41´N, 68º58´W], elev. [264m], 16.ix.1984, R. Faitoute leg., 1♀ ( USNM) . COSTA RICA: [San José]: San Jose , [9º56´N, 84º4´W], elev. [1152m], E. Schmidt leg., 1♀ ( AMNH) ; Machuca , [10º48´N, 83º36´W], elev. [14m], N. Banks leg., 1♀ ( MCZ 66544 ). PANAMA: [Chiriquí]: El volcán, [8º46´N, 82º37´W], elev. [1400m], 26.ii.1936, W. J. Gertsch leg., 3♀ 3♂ ( AMNH) . [Panamá]: Barro Colorado Island, Canal Zone , [9º9´N, 79º50´W], elev. [150m], vi.1950, A. M. Chickering leg., 1♀ ( MCZ 125496 ) ; Canal Zone, Forest reserve , [9º9´N, 79º50´W], elev. [150m], 29.i.1958, A. M. Chickering leg., 1♂ ( MCZ 129050 ) .

Figures

FIGURE 122. Glenognatha minuta from Mexico (AMNH). A – D, male habitus. A, dorsal. B, lateral. C, ventral. D, frontal. E – H, female habitus. E, dorsal. F, lateral. G, ventral. H, frontal. Scale bars, 200 µm. TS: tracheal spiracle.

FIGURE 123. Glenognatha minuta from Mexico (AMNH). A – C, male left chelicerae. A, anterior. B, posterior. C, mesal. D – F, female left chelicerae. D, anterior (arrow, cheliceral basal segment projection). E, posterior. F, mesal (arrow, cheliceral bulge). Scale bars, 100 µm. Prt: promarginal tooth. Ret: retromarginal tooth.

FIGURE 124. Glenognatha minuta from Mexico (AMNH). A – D, male left palp, schematic. A, ventral. B, conductor, ventral. C, conductor, dorsal. D, embolus, ventral. E – H, male left palp. E, ventral. F, dorsal. G, prolateral. H, retrolateral. Scale bars, 100 µm. C: conductor. CB: cymbium. CRa: conductor retrolateral apophysis. E: embolus. ED: ejaculatory duct. EMg: embolic medial groove. P: paracymbium. T: tegulum.

FIGURE 125. Glenognatha minuta. A – C, female genitalia. A, dorsal (arrow, uterus externus median projection). B, ventral. C, lateral (arrow, uterus externus median projection). D, spermathecae. E – G, female tracheal system. E, dorsal. F, median and lateral trunks. G, tracheal spiracle, posterior view. H, male left pap ventroretrolateral. I – J, embolus and conductor. I, ventroretrolateral. J, dorsal. K, paracymbium. Scale bars, 100 (A – C, E, H, K), 20 (F – G, I – J), 10 (D). C: conductor. CD: copulatory duct. CRa: conductor retrolateral apophysis. E: embolus. EMg: embolic medial groove. LSD: long-stem ducts. LT: lateral trunk. MC: membranous chamber. MT: median trunk. S: spermathecae. T: tegulum. TAG: tracheal atrium gland. UE: uterus externus.

FIGURE 137. Distribution of G. minuta, G. gouldi new species and G. emertoni.