Dubiaranea magatama Cajade, Hagopián & Rodrigues, 2024

Cajade, Manuel, Hagopián, Damián, Rodrigues, Everton N. L., Guerrero, José C., Laborda, Álvaro & Simó, Miguel, 2024, A new species and new records of the spider genus Dubiaranea (Araneae, Linyphiidae) from southern Brazil and Uruguay, with an analysis of the potential distribution of the species, Zootaxa 5437 (2), pp. 223-244 : 227-236

Dubiaranea magatama Cajade, Hagopián & Rodrigues new species

Figs 1–7

Type material. Holotype. URUGUAY: Durazno, from swamp native forest near La Paloma, 32°40’12.98”S, 55°39’34.44”W, 23–26.x.2021, D. Hagopián leg., 1M (FCE-Ar 13401) . Paratypes. URUGUAY: Maldonado, Sierra de Carapé , 34°31’25”S, 54°58’30.34”W), 23.xi.2019, M. Simó & G. Pompozzi leg., 1F (FCE-Ar 10761) . BRAZIL: Rio Grande do Sul, Derrubadas, Parque Estadual do Turvo , 27°8’44”S, 53°53’10”W, 4–7.v.2004, R. Ott et al. leg., 1M, 1F, 2Juv., Beating tray (MCN 39040) .

Additional material examined. BRAZIL. Paraná: Curitiba, 25°25’47”S, 49°16’19”W, 1.vi.1979, A. Yamamoto leg., 1M, Malaise trap (MCN 9276); Parque da Cidade, 25°25’52”S, 49°16’24”W, 1.xii.1990, A. B. Bonaldo leg., 1F ( MCN 20756); Almirante Tamandaré , 25°19’30”S, 49°18’36”W, 10.vii.1984, E. Corrêa Costa leg.,1F, Sweep net ( MCN 12510); 8.vi.1984, 1F ( MCN 12429); Telemaco Borba , 24°19’26”S, 50°36’57”W, 29.xii.1986, Equipe Profaupar leg., 1F, Malaise trap ( MCN 20674); 24.xi.1986, 1F ( MCN 20531) . Santa Catarina: Chapecó, 27°06’17”S, 52°36’51”W, 27.iv.2009, R. C. Francisco leg., 1M ( MCTP 28786); Concórdia , Campus da Universidade do Contestado, 27°14’02”S, 52°01’40”W, M. de O. Luz leg., 10.v.2008, 1F ( MCN 44485) . Rio Grande do Sul: Derrubadas, Parque Estadual do Turvo, 27°8’44”S, 53°53’10”W, 25-30.iv.2005, R. Ott et al. leg., 1F, Beating tray, ( MCN 39217); Machadinho , 27°34’01”S, 51°40’04”W, 1.i.1990, A. B. Bonaldo leg., 1F, Pitfall trap ( MCN 19321) ; Cambará do Sul, 29°02’52”S, 50°08’42”W, 25.xi.1993, A. B. Bonaldo & L. A. Moura leg., 1F ( MCN 24285); São Francisco de Paula, Centro de Pesquisas e Conservação da Natureza Pró-Mata , 29°26′17″- 29°34’42”S, 50°08’14” – 50°14’18”W, 13.xi.2001, R. Ott leg., 1M, Pitfall trap ( MCN 39381); 8.iii.2002, 1F ( MCN 39380); 3.iii.2001, 1F ( MCN 39379); 25.iv.1996, A.A. Lise leg., 1M, 1F ( MCTP 10515) S„o Francisco de Paula , 29°21’57”S, 50°48’57”W, 19–22.iii.1998, L. A. Moura leg., 3F ( MCN 29182); Canela, 29°21’57”S, 50°48’57”W, 21.iii.1976, A. A. Lise leg., 1F ( MCN 3592); 29.xii.1983 – 20.i.1984, M. Hoffmann leg., 1M, Malaise trap ( MCN 12222); Arroio do Meio , 29°24’03”S, 51°56’42W, 9.i.1985, A. A. Lise leg., 1F ( MCN 13054); Santa Maria, Perau Velho, 29°41’02”S, 53°48’25”W, 22.v.1996, C. B. Kotzian & L. Indrusiak leg., 1F, Beating tray ( MCN 33913); Porto Alegre, Reserva Biológica do Lami José Lutzenberger , 30°01’58”S, 51°13’48W, R. Moraes leg., 20.x–8.xi.2005, 1F, 1Juv. ( MCN 45580) . URUGUAY. Maldonado: Sierra de Carapé , 34°31’25”S, 54°58’30.34”W, 11.v.2019, M. Simó & A. Laborda leg., 1M, 2F (FCE-Ar 13275); same location and collectors, 15.xi.2019, 1F (FCE-Ar 10844), 3F, 2Juv. (FCE-Ar 10902), 1F, 1Juv. (FCE-Ar 10842), 1F, 2Juv. (FCE-Ar 10824), 1F, 2Juv. (FCE-Ar 10870) . Cerro Largo: Arévalo, 32°29’10.7”S, 55°04’55.5”W, 9–11.vii.2019, M. Simó & D. Hagopián leg., 1M, 2F (FCE-Ar 10954); same location and collectors, 31.x.2019 1M, 4F (FCE-Ar 12864), 2M, 1F (FCE-Ar 12812); 4–7.ii.2020, 3M, 1F (FCE-Ar 12389); Sierra de Ríos , 32°6’52.3”S, 54°0’11.1”W, 5.xi.2017, S. Teijón leg., 1F (FCE-Ar 8590), same location and date, Á. Laborda leg., 1M (FCE-Ar 8567); same location and date, J. Ginella leg., 1F (FCE-Ar 8554) . Lavalleja: Cerro Arequita , 34°17’20.1”S, 55°16’2”W, 16.xi.2012, Á. Laborda leg., 1F (FCE-Ar 3914) . Rivera: Cerro Miriñaque , 31°29’56.7”S, 55°38’59.9”W, 30.x.2010, M. Simó & Á. Laborda leg., 1M, 5F (FCE-Ar 4434) . Río Negro: El Matorral , 33°01’12.1”S, 57°33’59.7”W, 22.i.2020, M. Simó & D. Hagopián leg., 1M, 2F (FCE-Ar 12677), 1 F (FCEAr 12708); same location and collectors: 27.xi.2019, 1F, 1Juv. (FCE-Ar 12741); 4–7.viii.2019, 1F (FCE-Ar 10304), 3F (FCE-Ar 10311); 27.v.2020, 1M (FCE-Ar 11703) . Canelones: INIA, Las Brujas, 34°39’56.8”S, 56°20’51.5”W, 25.xi.2004, M. Simó leg., 1F (FCE-Ar 1586); same location and collectors: 21.xi.2004, 1F, 1Juv. (FCE-Ar 1363); 23.iv.2005, 1M, 3F (FCE-Ar 10376); Santa Lucía , 34°29’48.7”S 56°23’19”W, 2.xii.2018, D. Hagopián leg., 1M (FCE-Ar 10451) . Durazno: swamp native forests, near La Paloma, 32°40’12.98”S, 55°39’34.44”W, 23–26.x.2021, M. Simó & Á. Laborda leg., 1M, 1F (FCE-Ar 13399), 1F (FCE-Ar 13403), 1F, 1Juv. (FCE-Ar 13404), 1M, 4F (FCEAr 10375), 1M, 4Juv. (FCE-Ar 13405), 1M, 1F, 1Juv. (FCE-Ar 13400); same location: 19.x.2022, D. Hagopián leg., 1M, 1F (FCE-Ar 13921); swamp native forests, near La Paloma , 32°40’17.03”S, 55°39’35.45”W, 26.x.2021, M. Simó & D. Hagopián leg., 6F (FCE-Ar 13817) . Cerro Largo: Paso Arriera , 32°00’28.8”S, 54°27’48.7”W, 13–15.ii.2020, M. Simó & D. Hagopián leg., 3F (FCE-Ar 13190); same location and collectors, 10–13.xi.2019 1F (FCE-Ar 12793), 1F (FCE-Ar 12462), 2F (FCE-Ar 12278); 23.v.2020, 1M (FCE-Ar 11687); 7.vi.2019, 1M, 1F (FCE-Ar 11157) . Rivera: Ruta 30, Subida de Pena , 34°17’20.1”S, 55°16’2”W, 29.x.2010, M. Simó & Á. Laborda leg., 2F (FCE-Ar 4472) . Florida: Ruta 6, Arroyo Mansavillagra , 33°32’59”S, 55°43’23”W, 20.x.2022, D. Hagopián, V. Rodriguez & Á. Laborda leg., 1F (FCE-Ar 13923) .

Etymology. The species epithet is a noun in apposition and refers to the shape of the atria which resembles magatamas beads.

Diagnosis. Males of Dubiaranea magatama n. sp. resemble D. decurtata Millidge, 1991 (Figs 149–150; Millidge 1991) by the general appearance of the distal suprategular apophysis and of the embolic division ( Figs 1A–E , 3D–E ). Both, D. decurtata and D. magatama n. sp., differ from other congeners by having the distal suprategular apophysis distally curved downward, a short and broad anterior apophysis of the lamella characteristica and long and slender posterior apophysis of the lamella (as stated by Millidge 1991). Dubiaranea magatama n. sp. can be distinguished from D. decurtata by having a bifid distal suprategular apophysis ( Figs 1A–B , 3D ), without divisions in D. decurtata , and a rectangular or “swoosh-shaped” median apophysis of the lamella characteristica ( Figs 1C–D , 3E ), triangular in D. decurtata . Females are distinguished from all other species of the genus by having a “magatama-like” atria with a t-shape median plate ( Fig. 2A–B ), in opposition to a rectangular or trapezoid shape of the median plate in the other Dubiaranea species.

Description. Male holotype (FCE-Ar 13401). Total length 3.70. Carapace length 1.40, width 1.10. Clypeus height 0.30. Sternum length 0.90, width 0.70. Chelicerae length 0.70. Abdomen length 2.10, width 0.80, height 0.90. Leg formula I/II/IV/III; lengths (I/II/III/IV): femora 1.60/1.60/1.70/1.70; patellae 0.30/0.30/0.25/0.20; tibiae 1.60/1.50/0.90/1.40; metatarsi 2.10/1.80/1.10/1.80; tarsi 1.10/1.00/0.60/0.90; total 6.70/6.20/4.55/6.00. Palp (femur, patella, tibia, cymbium): 0.70/0.20/0.25/0.70. Separation coxae IV 0.20. Metatarsal trichobothria I–III present, IV absent. Tibial spine formula: 2-2-2-2. TmI 0.09. Eye diameters and interdistances: AME 0.10, ALE 0.075, PME 0.15 and PLE 0.075; AME―ALE 0.10, PME―PLE 0.075, AME―AME 0.06, PME―PME 0.125. Eyes with black margins, primarily AME and PME, setae present at ocular area. Eyes on black tubercles, mainly PME. Clypeus with tiny scarce setae. Chelicerae brown, granulated in anterolateral area and with small hairs; chelicerae paturon with numerous small hairs. Chelicerae promargin with four teeth in groups of two, retromargin with four tiny teeth, with setae between teeth. Dorsal spur in chelicerae absent. Chelicerae stridulatory striae scaly ( Fig. 3A ). Endites brown, except yellow serrula area, with setae. Labium dark brown. Sternum dark brown. Metatarsal lyriform organ present at distal end of metatarsus I ( Fig. 3B ). Legs long and slender, yellow; coxae pale yellow. Tarsal claws of leg I with main claws teeth crowded and similar in size, and middle hook with a subapical tooth ( Fig. 3C ). Carapace ( Fig. 1F–G ) light brownish, narrowed anteriorly, larger than wide, borders dark brown. Abdomen ( Fig. 1F–G ) oblong, longer than wide, dorsally brown with pale beige chevrons, laterally with two longitudinal pale beige bands with silver spots, ventrally pale black, prolonging after spinnerets. Spinnerets whitish brown. Coloration in live specimens see Fig. 4 A–C . Colulus whitish-brown, leaf-shaped, with setae. Paracymbium sclerotized ( Figs 1A , 3D ) with straight hook, large base, distally with acute apex. Paracymbium basal setae present ( Fig. 3D ). Embolus long, narrowed at apex next to the embolic membrane ( Figs 1A, 1E , 3D ). Embolic membrane well developed and bifid ( Figs 1A, 1E , 3E ). Protegulum present. Subtegulum large. Tegulum with sinuous margin and slightly sinuous duct ( Figs 1A , 3D ). Suprategulum sclerotized. Marginal suprategular apophysis crenate. Radix present. Tailpiece of radix present and sclerotized ( Fig. 1E ). Distal suprategular apophysis long and sclerotized, strongly bifid distally ( Figs 1A , 3D ). Lamella characteristica posterior apophysis large, distally pointed ( Figs 1A , 3D–E ). Median apophysis of the lamella characteristica rectangular and weakly serrated distally ( Figs 1C, 1E , 3E ). Anterior apophysis of the lamella characteristica short. Tibial apophysis absent. Palpal tibia with six macrosetae, two retrolateral and one dorsal trichobothria ( Fig. 1A ). Palpal patellae with a dorsal macrosetae ( Fig. 3D ). Fickert’s gland absent.

Female paratype (FCE-Ar 10761). Total length 3.75. Carapace length 1.30, width 0.85. Clypeus height 0.24. Sternum length 0.65, width 0.55. Chelicerae length 0.69. Abdomen length 2.50, width 1.60, height 1.70. Leg formula I/II/IV/III; lengths (I/II/III/IV): femora 1.59/1.44/1.05/1.47; patellae 0.36/0.33/0.27/0.30; tibiae 1.50/1.23/0.75/1.17; metatarsi 1.59/1.35/0.96/1.29; tarsi 0.96/0.84/0.57/0.54; total 6.00/5.19/3.60/4.77. Palp (femur, patella, tibia, tarsus): 0.33/0.12/0.24/0.45. Separation coxae IV 0.15. Metatarsal trichobothria I–III present, IV absent. Tibial spine formula: 2-2-2-2. TmI 0.14. Eye diameters and interdistances: AME 0.04, ALE 0.06, PME 0.10 and PLE 0.06; AME―ALE 0.06, PME―PLE 0.04, AME―AME 0.04, PME―PME 0.14. Eyes ( Fig. 2E–F ) with black margins, mainly PME, setae present at ocular area. Eyes on black tubercles, mainly PME. Clypeus with setae. Carapace ( Fig. 2E–F ) brown, narrowed anteriorly, larger than wide. Chelicerae brown, granulated in anterolateral area and with small hairs; chelicerae paturon with numerous small hairs. Chelicerae promargin with five teeth, retromargin with six tiny teeth. Endites brownish to yellowish, with yellowish serrula area, with setae. Labium yellowish. Sternum dark brown with setae, finely granulated. Legs long and slender, yellowish-brown; coxae yellow. Abdomen ( Fig. 2E–F ) ovate, longer than wide, dorsally brown with pale beige chevron pattern, laterally with two longitudinal sinuously pale beige bands with silver spots, ventrally brown, prolonging after spinnerets. Spinnerets yellow brown. Coloration in live specimens see Fig. 5 A–C . Colulus whitish-brown, leaf-shaped, with setae. Palpal tarsus with claw. Female epigynum with ventral plate large, with setae, longer than tall ( Fig. 2A ). Dorsal plate narrow, tongue shaped ( Fig. 2A, 2C ). Median plate T-shaped ( Fig. 2A ). Spermathecae U-shaped ( Fig. 2D ). Fertilization ducts in posterior portion of epigynum. Copulatory ducts long and very conspicuous spiraled, like a corkscrew in lateral view, with median trajectory close to each other ( Fig. 2D ).

Variation. Total length (6 males) 2.6–3.8; carapace length 1.08–1.6, carapace width 0.72–1.12; femur I 1.56– 2.16. Total length (6 females) 2.56–3.8; carapace length 0.92–1.36, carapace width 0.76–0.92; femur I 1.36–1.64. The colour pattern is quite variable, most of the individuals are dark, but some are lighter. In males, the shape of the suprategular apophysis can vary according to the angle of observation ( Fig. 1A–B ). The shape of the mesal apophysis of the lamella characteristica median apophysis varies from rectangular ( Fig. 1C, 1E ) to “swoosh”-shaped ( Fig. 1D ). In females, the shape of the margin of the median plate is always sinuous, but the degree of sinuosity can vary slightly among different individuals ( Fig. 2A–B ).

Natural history. Male webs range from 5 to 10 cm in length ( Fig. 4A–B ) and can be found very close to females’ webs. Female webs can vary from 7 to 20 cm in length ( Fig. 5A–B ). Webs are built between low and thin branches of understory vegetation. In accordance with Hormiga & Eberhard (2023) terminology, webs of D. magatama n. sp. have sparse densities of lines and present sticky lines ( Fig. 5A, C ). Dubiaranea magatama n. sp. was found in swamp, riparian, hill and ravine native forests from Uruguay and the Atlantic Forest in Brazil ( Fig. 6 ). Most females have translucent epigynal plugs covering the atria.

Distribution. Known for southern Brazil (states of Paraná, Santa Catarina and Rio Grande do Sul) and Uruguay (departments of Canelones, Cerro Largo, Durazno, Florida, Lavalleja, Maldonado, Río Negro and Rivera) ( Fig. 7 ). The model distribution shows that the species occurs in southern Brazil, Uruguay and with high favourable areas in coasts of Río de la Plata in Buenos Aires Province and Río Uruguay in Entre Ríos Province, Argentina. Four variables contributed to the final model. Of these, three showed a positive relationship: Spatial component (Wald: 16.991), Summation of Big Rivers (Wald: 8.2934) and Tree cover (Wald: 4.817) ( Table 2 ). On the other hand, Crops resulted in a negative relationship (Wald: 6.132) ( Table 2 ).

Figures

FIGURE 1. Dubiaranea magatama n. sp. Male pedipalp. A–B, ectal view. B, arrow shows variation in DSA according to the angle of observation. C–D, mesal view. D, arrow shows variation in the shape of the LCm. E, embolic division. Male Habitus. F, dorsal view. G, lateral view. Scale bars: A–E: 0.5 mm, F–G: 1 mm.

FIGURE 2. Dubiaranea magatama n. sp. Epigynum. A–B, ventral view. B, variation in epigynum proportions. C, posterior view. D, dorsal view. Female Habitus. E, dorsal view. F, lateral view. Scale bars: A–C: 0.5 mm, D–E: 1 mm.

FIGURE 3. Dubiaranea magatama n. sp. SEM images. A–E. A, male chelicerae. B, Metatarsal lyriform organ (arrow) at distal end of male metatarsus I. C, tarsal claws of leg I. D, male pedipalp in ectal view. E, male pedipalp in mesal view.

FIGURE 4. Dubiaranea magatama n. sp., male from a swamp forest in Durazno, Uruguay (photographed out of their environment) Habitus. A–C. A, ventral. B, lateral. C, dorsal.

FIGURE 5. Dubiaranea magatama n. sp., female from a swamp forest in Durazno, Uruguay. Habitus. A–C. A, ventral. B, lateral. C, dorsal.

FIGURE 6. Some of the environments where Dubiaranea magatama n. sp. can be found in Uruguay. A–C. A, swamp native forest (Durazno, Uruguay). B, riparian native forest (Maldonado, Uruguay). C, hill native forest (Maldonado, Uruguay).

FIGURE 7. Potential distribution of Dubiaranea magatama n. sp. obtained using the Favourability Function. White circles represent D. magatama n. sp. records.