Anatomy and systematics of Anodontites Elongatus (Swainson) from Amazon and Parana Basins, Brazil (Mollusca, Bivalvia, Unionoida, Mycetopodidae)

The anatomy of Anodontiies elongatus (Swainson, 1823), a rare species restricted to the Amazon and Parana Basins, is described by first time, showing a group of conchological and anatomical characters exclusive of this species that may be analyzed to identify it. Diagnosis of A. elongatus: shell long antero-posteriorly, umbones prominent, periostracum opaque and smooth, two posterior radial striae; middle fold of mantle edge veiy tall; gill long antero-posteriorly and short dorso-ventrally, extending about a half of it total length beyond visceral mass; palps proportionally small, several furrows in its outer surface; stomach without esophageal transversal ridjp, dorsal hood and gastric shield poorly developed, major typhlosole entering in ddd , posterior pouch of sa³ very-long; style sac reduced, without crystalline style; distal region of intestine and rectum with a well developed typhlosole, "T" in section, other intestinal regions without folds; gonad gonochoristic

Moluscos em área de horticultura no município de Porto Alegre, Rio Grande do Sul, Brasil Mollusca in horticultural production area in Porto Alegre county, Rio Grande do Sul, Brazil

<abstract language="eng">Horticultural production areas are favorable to development and maintenance of land mollusks populations. To know the mollusk fauna diversity in that kind of production area a research project was conduced in a rural-urban district of Porto Alegre, Rio Grande do Sul, Brazil. The production property studied is located in the Southern zone of the city and has 17 ha of cultivated area. The sampling period was from August/2000 to August/2001, with monthly quantitative collects on the different culture production beds previously selected. Six taxa were registered: Deroceras leave (Müller, 1774) (1.389 specimens = 82,82%), Bradybaena similaris (Férussac, 1821) (195 specimens = 11,7%), Succinea meridionalis d'Orbigny, 1846 (82 specimens = 4,9%), Lamellaxis gracilis (Hutton, 1834) (03 specimens = 0,17%), Bulimulus (Bulimulus) vesicalis angustus Weyrauch, 1966 (05 specimens = 0,3%) and Megalobulimus abbreviatus (Bequaert, 1948) (02 specimens = 0,11 %), only the last two being natives