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Five new species of the genus Plato (Araneae: Theridiosomatidae) in the caves of the states of Pará and Minas Gerais, Brazil.

Sousa PHPM, Cizauskas I, Brescovit AD

Laboratório Especial de Coleções Zoológicas, Instituto Butantan, Brasil

Introduction: The family Theridiosomatidae Simon 1881 is currently represented by 18 genera and 106 species. Among the genera of the family, Plato is represented by 6 species: Plato bicolor Keyserling 1886, P. bruneti Gertsch 1960, P. Guacharo Brignoli 1972 P. juberthiei Lopez 1996 P. miranda Brignoli 1972 and P. troglodita Coddington 1986 (type specie), P. bicolor being the only described for Brazil in the state of Amazonas. Species of this genus can be distinguished from other Theridiosomatidae genus by the presence of a medium escape on the posterior base of female epigynum, grooves on distal or mesal area of cymbium and a strong and curved ventral apophysis on the conductor of male palp. Since 2000 we have received abundant material of Plato genus from the collections of Carste Associated Consultants, from caves in North (state of Pará) and Southwestern (state of Minas Gerais) of Brazil. After screening this material has been used to describe and map species of the genus in the areas of greatest impact of mining in Brazil.  Objectives: Describe, compare and maping the species found in these caves from Brazil. Methods: Analysis for species identification, descriptions and measurements, all in millimeters, were performed with a magnifying glass Nikon SMZ 745T. the photos were taken with a Leica DFC 500 digital camera mounted on a stereo-microscope Leica MZ16A. Focal images were made with Leica Application Suite software, version 2.5.0 in LECZ. All material is deposited in the arachnids collection of Instituto Butantan. Results and Discussion: About 2800 specimens were examined and 5 new species were found: P. ferriferus sp. n. and P. striatus sp. n. in Pará and P. mocambeiro sp. n., P. novalima sp. n., and, P. morrodopilar sp. n. in Minas Gerais. P. ferriferus was the most abundant. P. mocambeiro male presents bifid embolus and small conductor, and female escape strong sclerotized forming a rounded arrow that curves slightly to dorsal region. P. novalima male presents conductor with a robust projection with three top tips and an elongated lower superior projection and female has great epiginal plate and independent escape, apart from the rounded previous curve of copulatory duct. P. morrodopilar male presents bifid embolus and protruded conductor with short and tapered tip, and female escape in "U" shape. P. ferriferus male presents robust conductor with a superior finger-like projection and a posterior short and rounded, and female epigynum similar to P. novalima, but differs by the straight previous curve of copulatory duct. P. striatus presents conductor like P. ferriferus, but differs by the conductor with the distal area in arrow-shaped and pointed upwards, and by stripes at the fourth pair of legs.

Supported by CNPq

10 - BIODIVERSITY 21th Annual Scientific Meeting of Instituto Butantan.