Agyneta hum Cajade, Rodrigues & Simó, 2023

Cajade, Manuel, Hagopián, Damián, Rodrigues, Everton N. L., Laborda, Álvaro, Maldonado, M. Belén & Simó, Miguel, 2023, Two new species of the spider genus Agyneta (Araneae, Linyphiidae) from Uruguay and Brazil, Zootaxa 5380 (6), pp. 562-576 : 563-567

Agyneta hum Cajade, Rodrigues & Simó new species

Figs 1 , 2 , 5 , 7 , 8

Type material. Holotype. URUGUAY: Río Negro, establecimiento El Matorral, in riparian forest, Negro River , 33°00’58.9”S, 57°33’16.5”W, 28.xi.2019, M. Simó & M. Cajade leg., 1M ( FCE-Ar 13039 ) . Paratypes. URUGUAY: Same data 1F (FCE-Ar 13953); same data 4FF, 3 MM (FCE-Ar 13954) ; Cerro Largo, Arévalo , in riparian forest, Negro River, 32°29’16.9”S, 55°02’51.0”W, 5.ii.2020, M. Simó & Á. Laborda leg., 3FF, 4 MM (FCE-Ar 12460) .

Additional material examined. URUGUAY: Cerro Largo: Arévalo, in riparian forest, Negro River , 32°29’16.9”S, 55°02’51.0”W, 24.v.2020, M. Simó & Á. Laborda leg., 1F (FCE-Ar 11021) ; same locality, 9– 11.vii.2019, M. Simó & Á. Laborda leg., 1F (FCE-Ar 11211 ; same locality, 7–10/vii/2019, M. Simó & D. Hagopián leg., 1F (FCE-Ar 10446) ; same locality, 7–10/vii/2019, M. Simó & D. Hagopián leg., 1F (FCE-Ar 10960) ; same locality, 7–10.vii.2019, M. Simó & M. Cajade leg., 1F (FCE-Ar 10986) ; same locality, 4–6.viii.2019, M. Simó & Á. Laborda leg., 1F, 4 MM (FCE-Ar 10326) ; same locality, 7–10.vii.2019, M. Cajade & M. Simó leg., 3FF, 2 MM (FCE-Ar 10404) ; same locality, 7–10.vii. 2019, M. Simó & Á. Laborda leg., 1M (FCE-Ar 10467) ; same locality, 9– 11.vii.2019, M. Simó & Á. Laborda leg., 1M (FCE-Ar 11209) ; same locality, 7–10.vii.2019, M. Simó & Á. Laborda leg., 1M (FCE-Ar 10974) ; same locality, 7–10.vii.2019, M. Simó & D. Hagopián leg., 1M (FCE-Ar 10989) ; same locality, 7–10.vii.2019, M. Simó & Á. Laborda leg., 2 MM (FCE-Ar 10961) ; same locality, 5.ii.2020, M. Simó & Á. Laborda leg., 3FF (FCE-Ar 12342) ; same locality, 7–10.vii.2019, M. Simó & Á. Laborda leg., 2FF, 5 MM (FCE-Ar 10959) ; Paso Arriera , in riparian forest, 32°00’19.0”S, 54°29’24.5”W, 10.xi.2019, M. Simó & D. Hagopián leg., 2 MM (FCE-Ar 12795) ; same locality, 13–15.ii.2020, M. Simó & M. Cajade leg., 2 MM (FCE-Ar 13205) ; same locality, 17–20.vii. 2019, M. Simó & M. Cajade leg., 1M (FCE-Ar 11178) ; Paso Centurión, Aduana , in riparian forest, 32°81.89”S, 53°43’57.31”W, 4.xi.2017, D. Hagopián & Á. Laborda leg., 2FF (FCE-Ar 8867) ; same data, 2FF (FCE-Ar 8702) ; same data, 2 MM (FCE-Ar 8687) ; Durazno: near La Paloma city, establecimiento Rincón del Río , in swamp forest, 32°32’41.63”S, 55°42’38.44”W, 4.iii.2022, M. Cajade & D. Hagopián leg., 1M (FCE-Ar 13720) ; Río Negro: establecimiento El Matorral, in riparian forest, Negro River , 33°00’58.9”S, 57°33’16.5”W, 22.i.2020, M. Simó & D. Hagopián leg., 10FF, 7 MM (FCE-Ar 12713) ; same locality, 27.v.2020, M. Simó & C. Rojas leg., 2FF, 2 MM (FCE-Ar 11755) ; same locality, 27.v.2020, M. Simó & C. Rojas leg., 1F (FCE-Ar 11719) ; same locality, 28.v.2020, M. Simó & D. Hagopián leg., 3FF, 5 MM (FCE-Ar 11705) ; same locality, 28.xi.2019, M. Simó & Á. Laborda leg., 1F, 16 MM (FCE-Ar 12754) ; same locality, 23.i.2020, M. Simó & Á. Laborda leg., 13FF, 7 MM , 1 Juv (FCE-Ar 12972) ; same locality, 27.v.2020, M. Simó & D. Hagopián leg., 1M (FCE-Ar 11177) ; same locality, 28.xi.2019, M. Simó & D. Hagopián leg., 18FF, 29 MM , 1 Juv (FCE-Ar 12851) ; same locality, 27.v.2020, M. Simó & Á. Laborda leg., 1M (FCE-Ar 11175) ; same locality, 22.i.2020, M. Simó & D. Hagopián leg., 2FF, 2 MM (FCE-Ar 12680) ; same locality, 23.i.2020, M. Simó & Á. Laborda leg., 6FF, 3 MM (FCE-Ar 12941) ; same locality, 28.v.2020, M. Simó & Á. Laborda leg., 2FF (FCE-Ar 11627) ; same locality, 4–6.viii.2019, M. Simó & D. Hagopián leg., 1M (FCE-Ar 10360) ; same locality, 4–6.viii.2019, M. Simó & Á. Laborda leg., 2 MM (FCE-Ar 10358) ; same locality, 28.v.2020, M. Simó & M. Cajade leg., 1M (FCE-Ar 12251) ; same locality, 28.xi.2019, M. Simó & M. Cajade leg., 1M (FCE-Ar 13014) . BRAZIL: Rio Grande do Sul: Arroio Grande, riparian forest of Piratini river , 31°54’06.47”S; 52°39’08.29”W, collected by beating tray, 15.xi.2008, E. N. L. Rodrigues leg., 1M, 3F ( IBSP 343842 ) .

Etymology. The specific epithet refers to the name of the river of the type locality and is a name in apposition from the Guaraní language “hû” that means “black”, and it was how this ethnic group called the Negro River because of the mighty river and the dark color of its water.

Diagnosis. Males of A. hum n. sp. resemble those of A. adami ( Millidge, 1991) in having the lamella characteristica wider in the apex and with thorns distally (Fig. 9; Rodrigues et al. 2013), but differ in lacking a basal lobe in the lamella characteristica (present in A. adami ) ( Figs 1A , 5B, 5D ), presence of apical pocket of paracymbium (absent in A. adami ) ( Figs 1A , 5B ), presence of posterior pocket of paracymbium (absent in A. adami ) ( Figs 1A , 5B ), presence of dorsal tibial apophysis (absent in A. adami ) ( Figs 1A, 1E , 5B ), dorsal cymbial tubercle rugose and apically rounded (smooth and acute in A. adami ) ( Figs 1B, 1F , 5C, 5E ), and ventral cymbial tubercle rugose, apically truncated and dentated (smooth and acute in A. adami ) ( Figs 1B, 1F , 5C, 5E ). Females resemble those of A. adami ( Millidge, 1991) in having oval epigynal slits (Fig. 420; Millidge 1991), but it differ in having the margins of the proximal part of the scape parallel (convex in A. adami ) and presence of pit hook depression (absent in A. adami ) ( Figs 2A , 7B ).

Taxonomic note. Due to the proximity of the species Agyneta hum n. sp. and A. adami , the listed below material of A. adami was examined:

BRAZIL: Amazonas: Manaus (Lago Janauari; 03°20’S; 60°17’W), 15.x.1987, J. Adis et al. leg., 1F ( IBSP 120159 ); vi.1987 – vii.1988, 2M and 9F ( IBSP 120152 , 120159 , 120180 , 120188 , 120190 , 120210 , 120214 , 120235 ) .

Description. Male holotype (FCE-Ar 13039). Total length: 2.01; carapace length: 0.93, width: 0.67; abdomen length: 1, width: 0.62.

CEPHALOTHORAX: Eyes diameters and interdistances: AME: 0.06, PME: 0.08, ALE: 0.08 and PLE: 0.07; AME–ALE: 0.05, PME–PLE: 0.05, AME–AME: 0.02, PME–PME: 0.03. Eyes margined with black, suffused with black between AME and between ALE and PLE. Carapace ovoid, longer than wide, brownish orange ( Figs 1G–H ). Labium orange. Sternum pale orange, with scattered setae. Clypeus height: 0.16. Chelicerae length: 0.53; brownish orange, with proximal promargin striated; seta-tipped tubercles absent; promargin four denticles and pointed projection, retromargin four denticles and pointed projection near the base of the fang. Cheliceral stridulatory organ ~71 striae, well-spaced getting closer together basally ( Fig. 5A ). ABDOMEN: Elliptic, longer than wide, dorsally brownish gray with median transverse light gray stripe ( Figs 1G–H ), ventrally light gray to brownish gray to the extremes. Spinnerets and colulus brownish gray. LEGS: light orange; leg I total length: 3.59; leg III total length: 1.91; Tm I: 0.31, Tm IV: absent. GENITALIA: Palpal retrolateral tibial apophysis pointed and sclerotized ( Figs 1A, 1E , 5B ); dorsal tibial apophysis well developed, finger-like ( Figs 1A, E , 5B ); two retrolateral trichobothria and a dorsal one ( Figs 1A, E ). Cymbium rounded; glabrous depression absent; retrolateral cymbial tubercle present with tiny spike; dorsal cymbial tubercle apically rounded and dentated; ventral cymbial tubercle apically truncated and dentated ( Figs 1A–B, 1F , 5B–C, 5E ); membranous region present ( Figs 1A , 5B ); prolateral notch absent ( Figs 1B , 5C ). Paracymbium apical pocket present, anterior pocket long and curved, posterior pocket present ( Figs 1A , 5B ). Embolus tip pointed, narrow at the apex becoming broader ( Figs 1B–C ); Fickert’s gland present basally of the sperm duct ( Fig. 1C ); ventral lamella absent ( Fig. 1C ); thumb short reaching below the embolus proper ( Fig. 1C ). Embolus proper peak shaped and set apically in the embolus ( Fig. 1C ). Anterior terminal apophysis long and narrow, tip with protrusions ( Figs 1A, D ); posterior terminal apophysis trisected (i.e., divided into three lobes nearly up to the base), basally with a large ensiform extension and a bifid semi-membranous prong ( Fig. 1D ). Embolic membrane fimbriated ( Figs 1A–B ); lamella characteristica t-shaped, longer than wide, with thorns distally ( Figs 1A, 1D , 5B, 5D ).

Female paratype (FCE-Ar 13953). Total length: 2.08; carapace length: 0.87, width: 0.58; abdomen length: 1.32, width: 0.75.

CEPHALOTHORAX: Eyes diameters and interdistances: AME: 0.05, PME: 0.06, ALE: 0.06 and PLE: 0.04; AME–ALE: 0.04, PME–PLE: 0.05, AME–AME: 0.02, PME–PME: 0.03. Eyes margined with black, suffused with black between AME and between ALE and PLE. Carapace ovoid, longer than wide, brownish orange ( Figs 2E–F ). Labium orange. Sternum light orange, with scattered setae. Clypeus height: 0.12. Chelicerae length: 0.42; brownish orange; seta-tipped tubercles absent; promargin four denticles (larger than the retromargin ones), retromargin four denticles. Cheliceral stridulatory organ ~59 striae, narrowly spaced throughout ( Fig. 7A ). ABDOMEN: Elliptic, longer than wide, gray ( Figs 2E–F ). Spinnerets and colulus brownish gray. LEGS: light orange, leg I total length: 3.22; leg III total length: 2.58; palpal tarsal claw absent; Tm I: 0.28, Tm IV: absent. Colulus present. GENITALIA: Epigynum with the proximal part of scape almost as wide as long and slightly wider than the lateral lobes, sides straight, slightly tapering apically; epigynal slits oval; pit hook depression shallow ( Figs 2A , 7B ); lateral lobes inner margins straights and outer margins convex; stretcher and pit small ( Figs 2A, 2C , 7B ). Median part of the scape long and narrow ( Figs 2C–D ); genital pores at the base of lateral lobes pockets ( Figs 2B–D ). Internal genitalia with a large, reniform dorsal receptacula ( Figs 2B–C ).

Variation. Total length (6 males): 1.87–2.10; carapace length: 0.85–0.93, width: 0.56–0.70; leg I total length: 3.36–3.85; leg III total length: 1.91–2.61. Total length (6 females): 1.90–2.14; carapace length: 0.75–0.87, width: 0.57–0.61; leg I total length: 3.14–3.34; leg III total length: 2.30–2.58. Coloration is variable in both sexes. Some males lack the median transverse light gray stripe in the abdomen and have a uniform brownish-gray or even white abdomen. Some females have a brownish-gray abdomen, with or without a white dorsal posterior spot.

Natural history: Agyneta hum n. sp. was found in native riparian and swamp forests. Both males and females were collected using pit-fall traps, leaf litter manual collection, manual collection, G-Vac and beating tray.

Distribution: Known from southern Brazil and Uruguay. The species was recorded in the following state of Brazil: Rio Grande do Sul; and departments of Uruguay: Cerro Largo, Durazno and Río Negro ( Fig. 8 ).

Figures

FIGURE 1. Agyneta hum n. sp. Male. A, palp, retrolateral view. B, palp, prolateral view. C, embolus, prolateral view. D, radical division, retrolateral view. E, palp tibia, dorsal view. F, cymbium, mesodorsal view. G–H, male habitus. Scale bars (A–F): 0.2 mm, (G–H): 1 mm.

FIGURE 2. Agyneta hum n. sp. Female. A, epigynum, ventral view. B, internal genitalia, ventral view. C, internal genitalia, dorsal view. D, internal genitalia, lateral view. E–F, female habitus. Scale bars (A–D): 0.2 mm, (E–F): 1 mm.

FIGURE 5. Agyneta hum n. sp. Male, SEM images.A, chelicerae. B, pedipalp (retrolateral view). C, pedipalp (prolateral view). D, detail of the lamella characteristica. E, dorsal and ventral tubercles (enclosed box of Fig. 5C). Scale bars (A–C): 0.1 mm, (D–E): 0.05 mm.

FIGURE 7. Agyneta hum n. sp. (A, B) and Agyneta unguiserrata n. sp. (C, D) Females, SEM images. A and C, chelicerae. B and D, epigynum. Scale bars: 0.1 mm.

FIGURE 8. A, Map distribution of Agyneta hum n. sp. (black circles) and Agyneta unguiserrata n. sp. (white squares). B, riparian native forest (Arévalo, Cerro Largo, Uruguay), A. hum n. sp. preferred habitat. C, grassland (near La Paloma city, Durazno, Uruguay), A. unguiserrata n. sp. habitat in Uruguay.