A new species of Urostreptus (Diplopoda, Spirostreptidae): description and chromossome number

Abstract

ABSTRACT. This work presents the description and chromosome number of Urostreptus atrobrunneus sp. nov. The genus until now had not been registered yet in the São Paulo State, Brazil. The meiotic analysis showed that the species presents 2n=24, XY. The C-banding revealed large blocks of constitutive heterochromatin and two heteromorphic chromosomal pairs, one of them corresponding to the sexual pair. Urostreptus Silvestri, 1895 belongs to Spirostreptidae, being distributed throughout South America and characterized for presenting a median prominent carina on the epiproctum. These animals have an average size and a thin body. KEYWORDS.The genus, described by SILVESTRI (1895) HOFFMAN (1980), their absence at the eastern and southeastern parts of the country is noteworthy.This work presents the description and chromosomal number of a new species of Urostreptus, widely distributed throughout the São Paulo State, southeastern Brazil. MATERIAL AND METHODSThe specimens were collected at different sites in the São Paulo State and in different seasons of the year. For the cytogenetical analysis, the specimens were collected at the counties of Rio Claro (22°23'59''S; 47°34'18''W) and Piracicaba (22°42'30''S; 47°38'01''W).For chromosomal analysis, individuals were starved for one week and then injected with colchicine 0.08%. After approximately 16 hours (overnight), the specimens were anesthetized and dissected in physiological solution. For the meiotical analysis, the testes were brought to the hypotonic state by incubation in tap water for five minutes, then fixed in Carnoy I and crushed in 45% acetic acid. The material was stained in 3% Giemsa and subjected to C-banding, according to SUMNER (1972), with slight modifications.The holotype was deposited in the collection of the Zoology Museum of the University of São Paulo (MZSP), SP, Brazil and paratypes in the collection of the Biology Department, Biosciences Institute (IBRC), São Paulo State University (UNESP), Rio Claro, SP, Brazil. RESULTS AND DISCUSSIONUrostreptus atrobrunneus sp. nov. Description. Small species, with a mean of 50 mm in length, 3 mm in diameter and 46 segments; color dark brown with a lighter prozona, totally covered by metazona; dark brown head, collum, telson and antennae. Collum marked laterally by one groove. Epiproct slightly projected over paraprocts.First pair of male legs. Strait coxa and divergent prefemural processes, orally projected.Gonopods (Figs. 1,2). Coxite with about half-length of telocoxite. Telocoxite enlarged at the distal portion and guided towards the inside. Paragonocel long,

Midgut of the diplopod Urostreptus atrobrunneus: structure, function, and redefinition of hepatic cells

“…These animals usually do not occur in high densities, but population explosions caused by environmental disturbances, climate changes, and use of pesticides that eliminate possible competitors, have been reported. The millipede Urostreptus atrobrunneus Pierozzi and Fontanetti, 2006 have become a nuisance to humans in infestation sites in urban centers of the state of Sao Paulo, Brazil. As a contribution to the understanding of this potential pest, this study describes the histology, histochemistry, and ultrastructure of the U. atrobrunneus midgut, and presents the redefinition of hepatic cells somewhat controversial in the literature.…”

“…The high proliferation rate of the millipede Urostreptus atrobrunneus, a species described by Pierozzi and Fontanetti (2006), in some urban centers in the state of Sao Paulo, have drawn the attention of several researchers (Boccardo, 1998;Fontanetti et al, 2007Fontanetti et al, , 2010aFontanetti et al, , b, 2012Moreira-deSousa and Fontanetti, 2012).…”

Chromosomal Features of the Endemic Pill Millipedes (<i>Arthrosphaera</i>: Sphaerotheriidae, Diplopoda) from Western Ghats, India

“…Fontanetti (1991Fontanetti ( -2000 also opines that in most of the Brazilian diplopods it is not possible to identify the larger pair of chromosomes as sex chromosomes. The heteromorphism between X and Y chromosomes is also reported by Pierozzi and Fontanetti (2006) in a new species of Urostrepters. Using C-banding technique, the X chromosome was marked by a large Cϩ block, whereas the Y chromosome had much smaller block.…”

Unexpected attraction of Urostreptus sp. (Spirostreptidae) to seed elaiosomes: a new resource record to millipedes’ diet

“…The genus Urostreptus comprises 12 species occurring exclusively in South America (Pierozzi & Fontanetti 2006).…”