Testes size in leptodactylid frogs and occurrence of multimale spawning in the genus Leptodactylus in Brazil

Although rare, some anurans show multimale spawning. Herein we present data on testes mass relative to body mass for 11 leptodactylids and report multimale spawning in Leptodactylus chaquensis and Leptodactylus podicipinus. Testes mass averaged 4.13% of body mass for L. chaquensis and 0.75% for L. podicipinus. Testes size of both leptodactylid species with multimale spawning show that they are large and close to values recorded for rhacophorid frogs with multimale breeding (0.71-7.79%). Large testes size in frogs with multimale spawning supports the sperm competition hypothesis.

Genetic variation within and among species of five sections of the genus Arachis L. (Leguminosae) using RAPDs

Some Arachis species are widely used as commercial plants, e.g. the groundnut A. hypogaea, an important source of good quality protein and oil, and A. pintoi and A. glabrata, that are utilized as forage species. Germplasm of most Arachis species is available in germplasm banks. However, little it is known about the genetic attributes of this germplasm, and mainly about its genetic variability, which is very important for its maintenance. In the present study RAPDs were used to assay the genetic variation within and among 48 accessions of five sections of the genus Arachis and to establish the genetic relationships among these accessions. Ten of 34 primers tested were selected for DNA amplification reactions since they yielded the largest numbers of polymorphic loci. A dendrogram was constructed based on data from the 10 primers selected. Eighty RAPD polymorphic bands were analyzed among the accessions studied. The relationships among species based on RAPDs were similar to those previously reported based on morphological, cytological and crossability data; demonstrating that RAPDs can be used to determine the genetic relationships among species of the different sections of the genus Arachis. In general, wide variation was found among accessions and low variation was found within the accessions that had two or more plants analyzed. However, higher polymorphism was found in the section Trierectoides and in one accession of A. major, indicating that generalizations should be avoided and each species should be analyzed in order to establish collection and maintenance strategies.

Phylogenetic analysis and redescription of the genus Henochilus (Characiformes: Characidae)

Henochilus, a characiform genus endemic to eastern Brazil is reviewed. A single species, Henochilus wheatlandii, from the Rio Doce and possibly the Rio Mucuri in the states of Minas Gerais and Espirito Santo is recognized and redescribed. The phylogenetic analysis indicates that Henochilus is most closely related to the clade consisting of Brycon and likely Chilobrycon.

Visual signaling and reproductive biology in a nocturnal treefrog, genus Hyla (Anura: Hylidae)

We investigated reproductive activity, courtship behavior, call structure, body size, clutch size, oviposition site, and reproductive mode of Hyla sp. (aff. ehrhardti). Males called in all months, but showed a peak of activity during the rainy season. Three pair formations were observed and courtship involved stereotyped behavioral sequences, including visual signaling. Males emitted three different vocalization types: advertisement calls, courtship calls, and a vocalization of unknown function. Females attained larger body sizes than males and deposited an average of 74.5 unpigmented eggs per clutch. Early larval stages are aquatic but restricted to water in constructed subterranean nests; subsequent to flooding of nests, exotrophic tadpoles live in ponds or streams. Courtship behavior in Hyla sp. (aff. ehrhardti) is complex and the diverse repertoire of limb movements, exhibited by males, probably provide visual stimuli to females in this nocturnal treefrog. Hyla sp. (aff. ehrhardti) belongs to the H. albomarginata group. Considering the reproductive modes in this group, the complexes of H. albosignata and of H. albofrenata can be considered more close related to each other than to the H. albomarginata complex. © Koninklijke Brill NV, Leiden, 2004.

Morphometric analysis of a population of diplopods of the genus Rhinocricus Karsch, 1881

Diplopods belonging to the subclass Helminthomorpha may present one or both leg pairs of the seventh diplosegment modified into structures that aid copulation, called gonopods. These structures are used as a taxonomic trait for the description of most species. In the genus Rhinocricus these structures are closely similar, so that it is difficult to distinguish species only on the basis of this trait. Two species, R. padbergi and R. varians, are found in the same habitat and present gonopods practically identical in shape; together they present a broad colour gradient, ranging from dark brown to light beige. Morphometric data for individuals of the experimental group were submitted to ANOVA and MANOVA, using Hotelling-Lawley Trace and generalized Mahalanobis distances (D 2) tests. The results demonstrated a relationship between size and colour, with darker individuals being larger. On the basis of this preliminary analysis, we may suggest that the two species are distinct since dark individuals are distant from medium- and light-coloured individuals according to the D 2 values. This seems to indicate a possible polymorphism of individuals belonging to R. padbergi which present close proximity in the values obtained. In all analyses, we observed that the main variables were diameter, length and telson size.

Revision of the South American freshwater genus Plagioscion (Teleostei, Perciformes, Sciaenidae)

The South American freshwater sciaenid genus Plagioscion is reviewed. Five of the 15 nominal species assigned to the genus are considered to be valid: Plagioscion squamosissimus, widely distributed in Atlantic drainages east of the Andes; P. auratus from the Río Orinoco and Río Amazonas basins; P. magdalenae from the Río Magdalena and Río Amazonas basins; P. ternetzi from the lower Río Paraná, Río Paraguay and Rio Uruguay basins; and P. montei from the Río Amazonas basin. Copyright © 2005 Magnolia Press.

The spiny dogfish (Squalus cubensis/megalops group): the envenoming of a fisherman, with taxonomic and toxinological comments on the Squalus genus.

The authors report a spiny dogfish (Squalus cubensis/megalops group) sting of a professional fisherman. He was injured on the left hand by the spine anterior to the fish's dorsal fin and manifested local edema, erythema, and excruciating pain for 6 h. Sharks of the genus Squalus megalops/cubensis and Squalus acanthias are found throughout the world; they have two spines in front of their dorsal fins and channels with a whitish mass containing large vacuolated cells which secrete venom. The Squalus genus has a complex taxonomy; the species involved in this injury belongs to the megalops/cubensis group. A detailed taxonomic and toxinological study on the Squalus genus is important and would complement other work on these fish, especially as stings in humans are very rare and not fully understood.

Cytogenetic study on three species of the genus Triatoma (Heteroptera: Reduviidae) with emphasis on nucleolar organizer regions

The use of banding techniques allows the recognition of chromosomal pairs and karyotypical arrangements. However, its application in Heteroptera holocentric chromosomes is limited. Thus, little is known about their structure, specially their Nucleolar Organizer Regions (NORs). A comparative analysis of the nucleolar characteristics present during spermatogenesis in Triatoma platensis, Triatoma protacta and Triatoma tibiamaculata seems to indicate that in this group of insects nucleolar fragmentation occurs after prophase I. The study of chromosomal structure of these triatomines indicates that NORs are located at some telomeric and interstitial autosome regions and at sexual chromosomes (X/X1X2).

Information on Brazilian ornamental species of the genus Tillandsia L. (Bromeliaceae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Tetrabdella neotropica (Acari: Bdellidae), a new genus and species from Brazil

Tetrabdella neotropica Hernandes & Feres n. gen., n. sp. is the first representative of the family Bdellidae from South America. It can be distinguished from other bdellid mites by the presence of two trichobothriae on tarsi III and IV. The subfamily Spinibdellinae is herein redefined to accomodate the new genus. A key to world genera of Bdellidae is presented. Copyright © 2006 Magnolia Press.

Systematic review of Neotropical genera of Lauxaniidae: 3. The genus Paracestrotus Hendel, 1925 (Diptera: Schizophora)

A review of the Neotropical Lauxaniidae genus Paracestrotus Hendel, 1925 is presented with redescription of P. gibbosus Hendel, 1925 and the description of a new species, P. pulchripennis sp. n., from Brazil, Pará, including illustrations and a key. Copyright © 2006 Magnolia Press.

A new genus and species of tarsonemid mite (Acari: Tarsonemidae) from Brazil

Biscutulumnemus neotropicus gen. nov., sp. nov. (Tarsonemidae: Tarsoneminae: Tarsonemini) is described from adult female and male mites, collected on Croton floribundus Spreng., from São José do Rio Preto, State of São Paulo, Brazil. This new genus resembles members of Dendmptus and Tarsonemus, but male mites have two triangular shields anterolaterally to the prodorsal shield and the sejugal apodeme is absent. In addition, Biscutulumnemus differs from Dendroptus by the presence of femoral seta l″ and tibial solenidion φ1 and the presence of a vestigial apodeme I on female mites. Unlike Tarsonemus, Biscutulumnemus has a beaklike gnathosomal capsule, a round flange on leg IV of male mites, and stigmata very close to v1 on the prodorsal shield of female mites. Copyright © 2006 Magnolia Press.

Transferability and use of microsatellite markers for the genetic analysis of the germplasm of some Arachis section species of the genus Arachis

The Arachis section is the most important of the nine sections of the genus Arachis because it includes the cultivated peanut, Arachis hypogaea. The genetic improvement of A. hypogaea using wild relatives is at an early stage of development in spite of their potential as sources of genes, including those for disease and pests resistance, that are not found in the A. hypogaea primary gene pool. Section Arachis species germplasm has been collected and maintained in gene banks and its use and effective conservation depends on our knowledge of the genetic variability contained in this material. Microsatellites are routinely used for the analysis of genetic variability because they are highly polymorphic and codominant. The objective of this study was to evaluate the transferability of microsatellite primers and the assay of genetic variability between and within the germplasm of some species of the Arachis section. Fourteen microsatellite loci developed for three different species of Arachis were analyzed and 11 (78%) were found to be polymorphic. All loci had transferability to all the species analyzed. The polymorphic loci were very informative, with expected heterozygosity per locus ranging from 0.70 to 0.94. In general, the germplasm analyzed showed wide genetic variation. © 2006 Sociedade Brasileira de Genética.

Identification of lattices from genus of compact surface

In this work we propose procedures for the identification of structure of group associate lattices from fundamental region F4g of regular tessellations {4g; 4g} in the Euclidian plane and hyperbolic plane, where g denote genus of compact surface. © 2006 SBrT.