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Nueva especie del genero Arctosa (Araneae, Lycosidae) del sur de Brazil.

A new species of the wolf spider genus Arctosa (Araneae, Lycosidae) from Southern Brazil

Introduction

Arctosa was proposed by C. L. Koch (1847) to include spiders of medium to large size; they are swift runners with relatively keen eyesight. Most dwell in sandy places such as seashores or the banks of rivers and lakes, though some occupy heath or lichen habitats in high mountains or artic tundra (Dondale & Redner, 1983).

This genus occurs from Northern and Central America to South America. It was revised by Dondale & Redner (1983); twelve species were described or redescribed and illustrated. Platnick (2008) lists a total of 162 described species to the world. Two species are recorded from Brazil, A. humicola Bertkau, 1880 (only female known) and A. pugil Bertkau, 1880 (only male known) and A. workmani (Strand, 1909) based on a female specimen from Paraguay. The careful examination of the illustrations and original descriptions of these two known species of Arctosa from Brazil and Paraguay showed that this previous species belongs to the genus Arctosa.

Dondale & Redner (1983) mentioned that Arctosa females do not carry the eggsacs attached to the spinnerets, instead, they keep them in holes excavated in the sand. However, females of the species here described were collected with the eggsac attached to the spinnerets (Fig. 2).

The objective of this work is to describe and illustrate a new species of Arctosa from Sapiranga, Southern Brazil.

Material and methods

The material examined is deposited in Museu de Ciencias e Tecnologia (MCTP) da Pontificia Universidade Catolica do Rio Grande do Sul (PUCRS). The nomenclature of the male palpus and female epigynum structures follows Redner & Dondale (1983). To study the excised epigyna, the soft tissue was removed by a combination of dissection with a small surgical blade and immersion in the enzyme tripsine for 24 hours at 25 [grados]C. The scanning electron micrographs (SEM) were made in Centro de Microscopia e Microanalises of Pontificia Universidade Catolica do Rio Grande do Sul. All the measurements are in millimeters.

The abbreviations related to eyes measurements, including diameter, interdistances and median ocular quadrangle are those routinely used in spider descriptions.

Arctosa sapiranga sp. nov.

Figs. 1-26

Types: Male holotype from Sapiranga (arroio Feitoria, 29[grados]35'43"S; 51[grados]02'56"W, 234 m), Rio Grande do Sul, Brazil, 19.II.2008, E. L. C. Silva leg., deposited in MCTP 19998. Female paratype, same locality, data and collector as holotype, deposited in MCTP 19999.

Etymology: The specific name is a noun, and refers to the type locality.

Diagnosis: The male of Arctosa sapiranga sp. nov. resemble those of A. serii Roth & Brown, 1976 (Dondale & Redner, 1983: 26, Figs. 57, 58) by the shape of the terminal and median apophysis, but can be distinguished by the longer and heavily sclerotized acute median and terminal apophysis (Figs. 6, 11, 12). And the female of Arctosa sapiranga is similar to A. perita (Latreille, 1799) (Dondale & Redner, 1983: 20, Figs. 46, 49) but dinners on the shape of the spermathecae (Fig. 10).

Description: Holotype male. Total length 4,64. Carapace (Figs. 3, 4), 2,48 long, 1,86 wide, light brown, with dark bristles forming scattered lines, some sparse white bristles laterally, darker on cephalic area (Fig. 5). Clypeus light brown, darker anteriorly, with four long bristles, 0,02 high. Anterior eye row straight, 0,50 wide; posterior 0,76 wide. Eye diameters, interdistances, and median ocular quadrangle: AME 0,08, ALE 0,07, PME 0,22, PLE 0,18; AME-AME 0,10, AME-ALE 0,04, PME-PME 0,20, PME-PLE 0,26, MOQ 0,36 long, frontal view, anterior width 0,26, posterior width 0,64. Chelicerae light brown, bristly (Fig. 17); promargin and retromargin of fang furrow with three teeth equidistant and equal in size (Fig. 16). Endites, 0,15 long, 0,05 wide, light brown, serrula prominent (Figs. 14, 15). Labium brownish, darker at anterior margin, 0.26 long, 0,24 wide. Sternum bristly, yellowish; 1,16 long, 1,10 wide. Legs light brown, with light brown annuli on femora, with bristles and setae (Figs. 19, 20); relative length: I-IV-III-II, I-femur 1,90/ tibia-patella 0,90/ metatarsus 0,60/ tarsus 0,36/ total 3,76; II-0,62/ 0,70/ 0,52/ 0,38/ 2,22; III-0,64/ 0,71/ 0,54/ 0,34/ 2,23; IV-0,86/ 1,00/ 0,98/ 0,50/ 3,34. Bothrium conspicuous (Fig. 21). Glandular pore on the lateral of left leg I (Fig. 18). Tarsal claw with eight teeth (Fig. 22). Abdomen 1,70 long, hairy, dark brown, lighter anteriorly, with three dark bands at the posterior portion (Figs. 2, 3). Venter yellowish, scattered setae. Median and terminal apophysis of male palpus strongly sclerotized and acute at apex (Figs. 6-8, 11, 12).

[FIGURE 1 OMITTED]

Female (Paratype, MCTP 19999). Total length 6,65. Carapace 2,79 long, 2,12 wide, coloration as in the male. Clypeus brownish, 0,10 high. Anterior eye row straight, 0,56 wide; posterior 0,84 wide. AME 0,08, ALE 0,10, PME 0,24, PLE 0,19; AME-AME 0,12, AME-ALE 0,06, PME-PME 0,22, PME-PLE 0,10, MOQ, 0,40 long, frontal view, anterior width 0,28, posterior width 0,70. Chelicerae: brownish; promargin of fang furrow with three teeth, middle largest, proximal smallest, retromargin with three teeth equidistant and equal in size. Sternum as in the male; 1,16 long, 1,20 wide. Labium light brown, lighter at anterior margin; 0,30 long, 0,32 wide. Legs as in the male, relative length: IV-I-II-III, I-femur 1,70/ tibia-patella 1,90/ metatarsus 1,30/ tarsus 0,90/ total 5,80; II -1,56/ 1,60/ 1,10/ 0,80/ 5,06; III-1,40/ 1,58/ 1,20/ 0,84/ 5,02; IV-1,71/ 1,72/ 1,76/ 1,10/ 6,29. Abdomen 3,45 long, as in the male. Spinnerets (Fig. 23): ALS (Fig. 24) fulvous, with numerous piriform gland spigots (pi) and the major ampullate gland spigots; PMS (Fig. 25) fuscous brown, with numerous aciniform glands spigots (ac) and minor ampullate gland spigot (ma); PLS (Fig. 26) whitish, with numerous aciniform glands spigots (ac). Epigynum with deeply excavated atrium (Figs. 9, 13). Spermathecae short, rounded at apex (Fig. 10).

[FIGURE 2 OMITTED]

Variation: Three males, carapace length 2,48-2,66; 1,84-1,86 wide. Eight females, carapace length 2,76-3,05; 1,95-2,26 wide.

Other material examined: BRASIL, Rio Grande do Sul: Sapiranga (arroio Feitoria), 1 female, 31.I.2004 (MCTP 19994), 1 female, 26.VI.2004 (MCTP 19995), 1 female, 28.XII.2007 (MCTP 19996), 2 males, 4 females, 19.II.2008 (MCTP 19997), all collected by E. L. C. Silva.

Distribution: Known only from the type locality (Fig. 1).

Natural history: Females carry eggsacs on spinnerets (Fig. 2). Males can be easily found under rocks in the shores of small freshwater streams all year long, but in the summer (December to March) both male and female adults are more abundant (field observation).

[FIGURES 3-10 OMITTED]

[FIGURES 11-18 OMITTED]

[FIGURE 19-26 OMITTED]

Acknowledgments

We wish to thank Dr. Charles D. Dondale and Dr. Volker Framenau for the help and suggestions. Mauricio Paz Franca of Centro de Microscopia e Microanalises (CEMM) of PUCRS for the SEM images. This study was supported by "Conselho Nacional de Desenvolvimento Cientifico e Tecnologico" (CNPq

N.o. 140282/2008-4 for ELCS). Literature cited

Dondale, C. D.; J. H. Redner 1983. Revision of the wolf spiders of the genus Arctosa C. L. Koch in North and Central America (Araneae: Lycosidae). J. Arachnol., 11:1-30.

Koch, C. L. 1847 Die Arachniden. Nurnberg, Vierzehnter Band, pp. 89-210, Funfzehnter Band, pp. 1-136, Sechszehnter Band, pp. 1-80.

Platnick, N. I. 2008 The World Spider Catalog, Version 9.0. American Museum of Natural History, on line http://research.amnh. org/entomology/spiders/catalog/INTRO1.html date of access: 25/09/2008.

Presentado: 02/10/2008

Aceptado: 07/12/2008

Publicado online: 26/02/2009

Estevam Luis Cruz Da Silva (1) & Arno Antonio Lise (1)

(1) Pontificia Universidade Catolica do Rio Grande do Sul (PUCRS), Museu de Ciencias e Tecnologia (MCTP), Laboratorio de Aracnologia, Predio 40, sala 167, Avenida Ipiranga, 6681, 90619-900, Porto Alegre, Rio Grande do Sul, Brasil. E-mail: estevamsilva@gmail.com; lisearno@pucrs.br
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Author:Cruz Da Silva, Estevam Luis; Lise, Arno Antonio
Publication:Revista peruana de biologia
Article Type:Report
Date:Feb 1, 2009
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