Agyneta jacksoni Braendegaard 1937
Creators: name: Dupérré, Nadine
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Linyphiidae
Agyneta
Agyneta jacksoni

description: Agyneta jacksoni (Braendegaard 1937)
Figs 116–122, map 5
Meioneta nigripes jacksoni Braendegaard, 1937: 7. (Description Ƥ).
Meioneta levinseni Wunderlich 1973: 419, f. 36. (Misidentification; removed 3 from synonymy of Meioneta nigripes, synonymy of Meioneta jacksoni, rejected).
Agyneta jacksoni Saaristo & Koponen 1998: 570, f. 4A–C, 5A–E. (Removed Ƥ from synonymy of M. levinseni, contra Wunderlich 1973: 420, elevated to species status and transferred from Meioneta).
Type material: Meioneta nigripes jacksoni Braendegaard 1937, 3 HOLOTYPE. (BMNH), NOT EXAMINED.
Diagnosis: Males are distinguished from most species of Agyneta by their L-shaped lamella characteristica (Fig. 116). From A. rurestris and A. nigripes by their rounded dorsal cymbial tubercle (Fig. 117), pointed in A. rurestris and A. nigripes (Figs 109, 124). Females are distinguished from most species by the presence of a deep pit hook depression (Fig. 120). From A. nigripes by the straight sides of the proximal part of scape (Fig. 120), oblique in the latter (Fig. 127). From A. maritima and A. dynica by the narrower pit hook depression (Fig. 120), broader in A. maritima and A. dynica (Figs 134, 141). From A. rurestris, see diagnosis for the latter.
Description: Male: Total length 1.98; carapace length 0.93, width 0.68.
CEPHALOTHORAX: Carapace dark orange-brown, shiny, finely reticulate; suffused with gray along margin, radiating lines. Sternum brown suffused with gray. Clypeus height 2. Chelicerae orange, apical part lighter, excavated; ~12 seta-tipped tubercles; promargin five denticles, retromargin four denticles joined together, both margins with rounded projections near base of fang. Cheliceral stridulatory organ ~39 striae, well spaced throughout. ABDOMEN: Uniformly light to dark gray. LEGS: Light yellow; leg I total length: 2.94; leg III total length: 2.11; Tm I: 0.26, Tm IV: absent. GENITALIA: Palpal retrolateral tibial apophysis short and rugose; dorsal tibial apophysis wide and rugose; two retrolateral trichobothria and a dorsal one (Fig. 116). Cymbium triangular; glabrous depression present (Fig. 116); dorsal cymbial tubercle rounded, smooth; ventral tubercle absent; prolateral notch shallow (Fig. 117). Paracymbium apical pocket short, anterior and posterior pockets short and curved (Fig. 116). Embolus tip pointed, concave; ventro-basally spiny; basally with spur and small row of spines; Fickert’s gland absent; ventral lamella thin, serrated; thumb short reaching well below the embolus proper (Fig. 118). Embolus proper set apically, dorsal part narrower (Fig. 118). Anterior terminal apophysis wide with short protrusions; posterior terminal apophysis striated; lamella characteristica large, serrated, ending in two small points, with a large, rounded extension (Fig. 119).
Female: Total length 1.79; carapace length 0.79, width 0.54.
CEPHALOTHORAX: Same coloration as male. Chelicerae yellow; promargin five teeth, retromargin five denticles. Cheliceral stridulatory organ visible ~26 striae, well spaced. ABDOMEN: Same as male. LEGS: Same as male; palpal tibia and tarsus brownish, tarsal claw absent; leg I total length: 2.53; leg III total length: 1.90; Tm I: 0.27, Tm IV: absent. GENITALIA: Epigynum with wide proximal part of scape, straight, vertical sides; epigynal slits oval and short; pit hook depression deep (Fig. 120); lateral lobes wide and short, folded; stretcher and pit small (Fig. 121). Median part of scape long; genital pores situated at base of lateral lobes pockets (Fig. 122). Internal genitalia with a rounded ventral receptacula and a small, oval dorsal one (Fig. 121).
Other material examined: CANADA: Northwest Territories: Involuted Hills, 20–24.vi.1980, pan trap, old foreshore, 1Ƥ, 01–06.vii.1980, 33, L. Humble (CNC); Tuktoyaktuk, 04.vii.1971, pan trap, 33, D. Oliver (CNC). Yukon Territory: km 155 Dempster Hwy., 23.vii.1982, tundra on depression on ridge of dolomie, 13, D. Wood (CNC). USA: Maine: Baxter State Park near Caribou Spring, Mt. Katahdin, 1371m, 26.vi–23.vii.1986, 1139Ƥ, C. Dondale, J. Redner, D. Jennings (CNC); Baxter State Park near jct. Cathedral & Baxter Peak, 1371m, 26.vi– 23.vii.1986, 17311Ƥ, C. Dondale, J. Redner, D. Jennings (CNC). Washington: SW of Rocky, 1264m, 13– 14.vi.1994, pitfalls, alpine tundra, 13, E. West (UWBM). Wyoming: Yellowstone Park, Bridge Bay, 20.vi. 1938, 131Ƥ, W. Ivie (AMNH); Yellowstone Park, 21.vi.1938, 13, W. Ivie (AMNH).
Distribution: Greenland, Alaska to Newfoundland, southeast to Maine with isolated localities in Wyoming and Washington.
MAP. 5. Localities of Agyneta jacksoni (Braendegaard 1937), distribution based on material examined, distribution based on Paquin et al. 2010 and distribution based on Saaristo & Koponen, 1998.
description: Published as part of Dupérré, Nadine, 2013, Taxonomic revision of the spider genera Agyneta and Tennesseellum (Araneae, Linyphiidae) of North America north of Mexico with a study of the embolic division within Micronetinae sensu Saaristo & Tanasevitch 1996, pp. 1-189 in Zootaxa 3674 (1) on pages 40-42, DOI: 10.11646/zootaxa.3674.1.1, http://zenodo.org/record/283954