Biological aspects of Omalonyx convexus (Mollusca, Gastropoda, Succineidae) from the Rio Grande do Sul State, Brazil

Resumo

Omalonyx convexus (Heynemann, 1868) is widely spread throughout the Rio Grande do Sul State, Brazil. The studied specimens presented in vivo, tegument and mantle coloring in variations between milky-white, orange and beige. The shell presented itself covered by the mantle in different extents; however, it was not completely covered on any of the specimens. The feeding diet is basically constituted by vegetal tissues, although non-vegetal food items were also found. The specimens were found in preserved and in polluted fresh water environments, as well as on natural and artificial substrates. The temperature throughout the day influences their placement on habitat substrates.