José Willibaldo Thomé

Phillocaulis variegatus: an intermediate host of Angiostrongylus costaricensis in south Brazil

Molluscs collected in five localities in the State of Rio Grande do Sul (Brazil) were digested and examined. The infected slugs were identified as Phyllocaulis variegatus and the larvae found were inoculated per os into mice. After 50 days, worms with the caracteristics of Angiostrongylus costaricensis were recovered from the mesenteric arterial system. The results establish the role of P. variegatus as intermediate host of A. costaricensis in south Brazil, where many cases of abdominal angiostrongyliasis have been diagnosed.

On the diversity of mollusc intermediate hosts of Angiostrongylus costaricensis Morera & Cespedes, 1971 in southern Brazil

Veronicellid slugs are considered the most important intermediate hosts of Angiostrongylus costaricensis, an intra-arterial nematode of rodents. Studies undertaken in three localities in southern Brazil led to identification of molluscs other than veronicellid slugs as hosts of A. costaricensis: Limax maximus, Limax flavus and Bradybaena similaris. These data indicate a low host specificity of larval stages of A. costaricensis, as it has been reported to other congeneric species.

Report on the occurrence of Angiostrongylus costaricensis in southern Brazil, in a new intermediate host from the genus Sarasinula (Veronicellidae, Gastropoda)

Veronicellid slugs are the main intermediate hosts for Angiostrongylus costaricencis. In a rural locality in Nova Itaberaba (SC, southern Brazil) Sarasinula linguaeformis was identified as a crop pest. The parasitological examination revealed A. costaricencis infection in 43 out ot 50 slugs. The prevalence of 86% and the individual parasitic burdens are the highest sofar reported in Brazil and S. linguaeformis is the first species from the genus Sarasinula to be identified as intermediate host for A. costaricencis in southern Brazil.

Natural infection of Deroceras laeve (Mollusca: gastropoda) with metastrongylid larvae in a transmission focus of abdominal angiostrongyliasis

Angiostrongylus costaricensis is a nematode parasitic of rodents. Man may become infected by ingestion of the third stage larvae produced within the intermediate hosts, usually slugs from the family Veronicellidae. An epidemiological study carried out in a locality in southern Brazil (western Santa Catarina State) where these slugs are a crop pest and an important vector for A. costaricensis has documented for the first time the natural infection of Deroceras laeve with metastrongylid larvae. This small limacid slug is frequently found amid the folds of vegetable leaves and may be inadvertently ingested. Therefore D. laeve may have an important role in transmission of A. costaricensis to man.

Unique Ca2+-activated ATPase in the nervous ganglia of Phyllocaulis soleiformis (Mollusca)

Nucleotide-metabolizing enzymes play important roles in the regulation of intracellular and extracellular nucleotide levels. We studied ATPase activity in the nervous ganglia of Phyllocaulis soleiformis, a terrestrial slug. The ATPase was divalent cation-dependent, with a maximal rate for ATP hydrolysis at pH 6.0 and 7.2 in the presence of Ca(2+) (5 mM). Mg(2+)-ATPase activity was only 26% of the activity observed in the presence of Ca(2+) (5 mM). ZnCl2 (10 mM) produced a significant inhibition of 70%. Ca(2+)-ATPase activity was insensitive to the classical ATPase inhibitors ouabain, N-ethylmaleimide, orthovanadate and sodium azide. Levamisole, an inhibitor of alkaline phosphatase, was ineffective. Among nucleotides, ATP was the best substrate. The apparent K(m) ((ATP)) for Ca(2+)-ATPase was 348+/-84 microM ATP and the V(max) was 829+/-114 nmol Pi min(-1) mg(-1) protein. The P. soleiformis ganglial ATPase does not appear to fit clearly into any of the previously described types of Ca(2+)-ATPases.

A Newly Introduced and Invasive Land Slug in Brazil: Meghimatium pictum (Gastropoda, Philomycidae) from China

ABSTRACT. The land slug Meghimatium pictum (Stoliczka, 1873), native to China, is recorded for the first time in Brazil. This is also the first record of a species of the eastern Asiatic genus Meghimatium on the American continents. The species was identified using morphological criteria and analysis of the cytochrome oxidase subunit I, COI. Our records indicate this species is widely distributed in southern and southeastern Brazil, in the States of São Paulo, Paraná, Santa Catarina and Rio Grande do Sul, in disturbed and natural areas. We morphologically characterize M. pictum (external characteristics, reproductive system, jaw and radula) and provide some biological information based on field observations. We also discuss when M. pictum was probably introduced, from whence it came, possible pathways of introduction, and its characteristics as an invasive species and potential agricultural pest.

Molecular phylogeny of the South American land slug Phyllocaulis (Mollusca, Soleolifera, Veronicellidae)

Gomes, S. R., Britto da Silva, F., Mendes, I. L. V., Thomé, J. W. & Bonatto, S. L. (2009). Molecular phylogeny of the South American land slug Phyllocaulis (Mollusca, Soleolifera, Veronicellidae). —Zoologica Scripta, 39, 177–186.

Descrição do ciclo reprodutivo de Donax hanleyanus (Bivalvia, Donacidae) no sul do Brasil

The changes in gonadal development in male and female of Donax hanleyanus Philippi, 1847 are described. Gonad development and spawning seasons were assessed by monthly sampling of population from Arroio Teixeira beach, southern Brazil. Histological examination of clams showed in the most of the adult population sampled that the spawning is practically continuous, without any period of sexual rest. There are two main periods of gametogenesis, in winter and in summer, being the degree of maturation longer in the latter. The water temperature is stimulant on gametes proliferation and spawning.

Proporção sexual e comprimento de concha na primeira maturação sexual em Donax hanleyanus Philippi (Bivalvia, Donacidae) no Rio Grande do Sul, Brasil

Sex ratio and size at first maturity of the wedge clam Donax hanleyanus Philippi, 1847 were studied during 15 months, between October 2001 and December 2002, in Arroio Teixeira beach, southern Brazil. Circa of 3000 specimens were collected in swash zone and the length shell varied between 2.0 and 28.33 mm. 347 specimens, between 7.0 and 28.3 mm, were analyzed histologically. The sex ratio was 1:1. Different methods were employed in order to give a better idea of the mean size at first maturity. Donax hanleyanus attain maturity at mean lengths between 12.28 mm and 12.60 mm. A minimum size of 15,0 mm (ca. eight months) for extraction is suggested.

Revalidation of Phyllocaulis renschi (Mollusca: Gastropoda: Veronicellidae) based on radula and mandible structures of taxonomic significance for the genus

Phyllocaulis is a slug genus distributed throughout the south‐eastern and southern regions of Brazil, also Uruguay, Argentina and Chile. The determination of the species is almost exclusively based upon anatomical and morphological characters, mainly of the penis, spathe and the penial and pedal glands. Here we can show also that structure of the mandible and of the radula allow separation of the species P. boraceiensis, P. gayi, P. renschi, P. soleiformis (forms A, B, D and E), P. tuberculosus and P. variegatus. We present pictures obtained by scanning electronic microscopy of the taxonomically relevant details. Width and length of the central tooth and the width of the lateral tooth of the radula are regarded as most important for biometric differentiation between the species. This approach permitted the revalidation of Phyllocaulis renschi Thomé, 1965, a species which in the meantime had been placed under the synonymy of P. soleiformis (form C). Phyllocaulis é um gênero de lesmas distribuído nas regiões sudeste e sul do Brasil, também no Uruguai, Argentina e Chile. A determinação das espécies de Phyllocaulis está baseada quase que exclusivamente na descrição de caracteres anatômicos e morfológicos, principalmente a forma do pênis, da espata, da glândula peniana e da glândula pediosa. As mandíbulas e os dentes da rádula das espécies P. boraceiensis, P. gayi, P. renschi, P. soleiformis (formas A, B, D e E), P. tuberculosus e P. variegatus, foram analisadas através da microscopia eletrônica de varredura. Os caracteres específicos mais importantes foram: largura e comprimento do dente central e largura do dente lateral da rádula. Os resultados evidenciaram que esses característicos possibilitam a diferenciação entre as espécies. Isto permitiu também revalidar a espécie Phyllocaulis renschi Thomé, 1965, que se achava sinonimizada sob P. soleiformis (forma C).