This paper reports the preliminary results of two years of herpetogeographic studies in the region called «Grande Porto Alegre» at its northern portion. The physiognomy shows, at North, slopes of the Brazilian Southern Plateau, more or less forested in a general view; these elevations graãuálly decrease to the South until the levei of the sea to Atlantic littoral by the eastern border, and to Rio Grande do Sul savanah, which extends to Uruguay and Argentina. The biota is transitional from the highland prairies and forests of the plateau to lowland prairies of the pampas. Three faunistic Provinces are included: Guarani, Pampean, and Tupi. The most conspicuous dispersion is shown by the taxa proceeding from the plateau to savanah (Dispersion Centre Guarani); the pampean species occur in low percentage (Dispersion Centre Uruguay), and an inappreciable account of Tupi fauna (Dispersion Centre of «Serra do Mar»). The new records are: presence of Chironius pyrrhopogon, Hydrodynastes gigas, Bothrops neuwiedi para-naensis, Micrurus corallinus; intergradation zone of Guarani and Pampean geographic roces; and new taxa of snakes, which will be described brieflly. The systematic composition presents: Chelonia, 4 (3 Chelidae, 1 Testudinidae); Sauria, 10 (1 Gekkonidae, 2 Iguanidae, 1 Anguidae, 3 Teiidae, 3 Amphisbaenidae); Serpentes, 45 (35 Colubridae, 4 Elapidae, 6 Viperidae); Crocodylia (1 Crocodylidae)

BackgroundSnakebite treatment requires administration of an appropriate antivenom that should contain antibodies capable of neutralizing the venom. To achieve this goal, antivenom production must start from a suitable immunization protocol and proper venom mixtures. In Brazil, antivenom against South American rattlesnake (Crotalus durissus terrificus) bites is produced by public institutions based on the guidelines defined by the regulatory agency of the Brazilian Ministry of Health, ANVISA. However, each institution uses its own mixture of rattlesnake venom antigens. Previous works have shown that crotamine, a toxin found in Crolatus durissus venom, shows marked individual and populational variation. In addition, serum produced from crotamine-negative venoms fails to recognize this molecule.MethodsIn this work, we used an antivenomics approach to assess the cross-reactivity of crotalic antivenom manufactured by IVB towards crotamine-negative venom and a mixture of crotamine-negative/crotamine-positive venoms.ResultsWe show that the venom mixture containing 20% crotamine and 57% crotoxin produced a strong immunogenic response in horses. Antivenom raised against this venom mixture reacted with most venom components including crotamine and crotoxin, in contrast to the antivenom raised against crotamine-negative venom.ConclusionsThese results indicate that venomic databases and antivenomics analysis provide a useful approach for choosing the better venom mixture for antibody production and for the subsequent screening of antivenom cross-reactivity with relevant snake venom components.

ABSTRACT. Morphometric variation in Bothropoides jararaca (Snakes, Viperidae) in Rio Grande do Sul. Although male and female snakes are born with the same size, growth rates and age of sexual maturation may be different, thus determining sexual dimorphism in the later stages of life. We evaluated the incidence of sexual and ontogenetic morphometric variation in Bothropoides jararaca (Wied, 1824), exploring relationships involving body size and sexual maturity through 14 morphometric variables. We analyzed 142 specimens from the state of Rio Grande do Sul, southern Brazil. Morphometric data -head length, snout-vent length, tail length, total length; head width, ocular width, nasal-loreal width, tail width; nasal-ocular distance, ocular-loreal distance, loreal-nasal distance, ventral-sinfisal distance and rostral-labial distance -and length/ diameter of ovarian follicles, were taken in millimeters by simple rule and analogical caliper, precision 0.05 mm. Sex determination was performed by inspection of the gonads. Age was associated to sexual maturity. For the statistical analysis the analysis of variance (ANOVA) with Tukey's post hoc test was used with, linear regression and canonical discriminant analysis (CDA). Most measures indicated sexual dimorphism (ANOVA, P<0.05) only in adults (Tukey, P<0.05). Regression analysis showed that snout-vent length explains the behavior of other variables (P< 0.001) and in all measures, females grow more than males. The ADC has been successful in separating the genders and age groups, with biological meaning, whereas 79.2% of cases were correctly classified. KEYWORDS.Ontogeny, morphology, dimorphism. RESUMO.Apesar de machos e fêmeas de serpentes nascerem com o mesmo tamanho, as taxas de crescimento e a idade da maturação sexual podem ser diferentes, determinando dimorfismo sexual em estágios posteriores da vida. Avaliamos a ocorrência de variação morfométrica sexual e ontogenética em Bothropoides jararaca (Wied, 1824), explorando as relações entre tamanho corporal e amadurecimento sexual através de 14 variáveis morfométricas. Foram analisados 142 espécimes provenientes do estado do Rio Grande do Sul, sul do Brasil. Os dados morfométricos -comprimento da cabeça, rostro-cloacal, da cauda, comprimento total; largura da cabeça, ocular, nasal, loreal, da cauda; distância ocular-nasal, ocular-loreal, loreal-nasal, ventral-sinfisal e rostral-labial -e comprimento/diâmetro dos folículos ovarianos, foram tomados em milímetros, através de régua simples e paquímetro analógico de precisão 0,05 mm. A determinação sexual foi realizada por inspeção das gônadas. A classificação etária foi associada à maturidade sexual. Para as análises estatísticas foram utilizadas análises de variância (ANOVA) com teste de Tukey post hoc, regressão linear e análise discriminante canônica (ADC). A maioria das medidas indicou dimorfismo sexual (ANOVA, P<0,05) apenas em adultos (Tukey, P<0,05). As análises de regressão mostram que o comprimento rostro-cloacal explica o comportamento das demais variáveis (P<0,001...

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