Alien invasive snail on native forest in Morretes, PR: diagnostic of the Achatina fulica Bowdich, 1822 population in an remnant of alluvial Ombrophylous Dense Forest

Abstract

The giant African snail Achatina fulica is frequently found in antropic environments in different Brazilian municipal districts, which leads to consider the possibility that its establishment is associated to disturbed habitats. For this reason, the objective set in this paper is to diagnose the occurrence and the population characteristics of the invasive snail in an Atlantic forest fragment in the municipal district of Morretes of the State of Paraná. Although the fragment is a secondary forest, few species of non-native vegetation were found there, and the area is characterized by great floristic diversity. There were collected 396 snails and large spacing was registered between the animals. The animals were found in activity and mainly on the ground during the whole morning period, which provides evidence of expanded forage periods. Results suggest that the animals present in the native forest fragment constitute a recently arrived population, resultant mainly of the saturation of disturbed areas under human influence. This implies urgency for measures to control and decrease populations of giant African snails in urban areas as a way to avoid invasion of natural forests.