Description and ecological notes on Isoctenus malabaris sp. nov. (Araneae, Ctenidae) from southern Brazil

Abstract

ABSTRACT.A new species, Isoctenus malabaris, is described from southern Brazil. This spider was abundantly collected with pitfall traps at Araucaria Forests (Mixed Ombrophilous Forest) domain. The activity of this species was studied in three distinct habitats (primary and secondary forests and silvicultures) during 20 months. A bimodal seasonal activity pattern, of males, was observed. Abundance differences of this species between habitats were not significant. KEYWORDS.Neotropical region, spiders, taxonomy, phenology.RESUMO. Descrição e notas ecológicas de Isoctenus malabaris sp. nov. (Araneae, Ctenidae), do Sul do Brasil. Uma nova espécie, Isoctenus malabaris, é descrita para sul do Brasil. Espécimes desta aranha foram abundantemente coletados com armadilhas de queda em área de domínio da Floresta com Araucária (Floresta Ombrófila Mista). A atividade da espécie foi estudada em três hábitats distintos (florestas primárias e secundárias e silviculturas) ao longo 20 meses. Foi observado um padrão bimodal de atividades ao longo do ano, para espécimes machos. A diferença na abundância desta espécie entre os hábitats não foi significativa.

Revision and cladistic analysis ofIsoctenusand description of a new neotropical genus (Araneae, Ctenidae, Cteninae)

“…Isoctenus Bertkau, 1880: 61. Type species Isoctenus foliiferus Bertkau, 1880, by monotypy; Pickard‐Cambridge, 1897; Mello‐Leitão, 1936; Bonnet, 1957: 2311–2312; Lehtinen, 1967: 241; Silva, 2003; Polotow et al. , 2005, 2007; Platnick, 2008.…”

“…Isoctenus malabaris Polotow et al. , 2007: 216, figs 1–5 (male holotype and female paratype from Centro de Pesquisas e Conservação da Natureza Pró‐Mata (29°28′21″S, 50°09′25″W), São Francisco de Paula, Rio Grande do Sul, Brazil, 02.i.2001, R. Ott, deposited in MCN 39321, examined; paratypes with same data as holotype: 3 males and 3 females, deposited in IBSP 51957, 51958; MCTP 17142, 17143; MZSP 25327, 25328, examined).…”

“…Lehtinen (1967) considered Isoctenus as an independent genus and removed it from synonymy of Ctenus . Currently, ten species are described in this genus (Polotow, Brescovit & Ott, 2007; Platnick, 2008).…”

“…Diagnosis: Isoctenus malabaris resembles I. strandi by the morphology of tibia and presence of two small apical spines in male palp (Polotow et al. , 2007, figs 1, 2) and morphology of the spermathecae in the epigynum (Polotow et al. , 2007, figs 3–5), but can be distinguished by conical ventral branch of RTA, slender dorsal branch of RTA, elongated embolus (Fig.…”

“…, 2007, figs 3–5), but can be distinguished by conical ventral branch of RTA, slender dorsal branch of RTA, elongated embolus (Fig. 19D) and robust median apophysis in male palp (Polotow et al. , 2007, figs 1, 2) and by the oval median field projected posteriorly and short lateral spurs in the epigynum (Polotow et al.…”