Diversity of Terrestrial Malacofauna, Favorable Habitats, and Relationships With Mollusk Size in Urban Environments of Sergipe, Northeastern Brazil

ABSTRACT Terrestrial mollusks can benefit significantly from favorable environmental conditions and the creation of new habitats, enabling them to establish and proliferate in urban environments. This study aimed to analyze the diversity of terrestrial mollusks during the dry and rainy seasons and across different types of urban environments in the city of Aracaju, Sergipe, assessing their most favorable habitats as well as the size of the animals in these locations. Active searches were conducted during two climatic periods in standardized plots of 20 m × 10 m (20 min/two collectors), encompassing three habitat types (urban park, back garden, vacant lot) located in the neighborhoods of Atalaia, Farolândia, Jardins, and Santa Maria. A total of 957 live mollusks were collected, belonging to 8 families and comprising 11 distinct species. Achatina fulica (39.06%) and Subulina octona (19.80%) were classified as eudominant species. The highest abundance was recorded during the rainy period (67.9%; p < 0.001), whereas the opposite pattern was observed in the Santa Maria neighborhood (57.8%; p < 0.001). Back gardens (H′ = 1.64; S = 8) and vacant lots (H′ = 1.48; S = 7) showed similar diversity and richness, both being favorable habitats for mollusks. A. fulica exhibited larger shell size and weight in back gardens, whereas other snails displayed greater dimensions in the urban park ( p < 0.05). Understanding these factors will contribute to the conservation of local biodiversity and to the control of invasive or epidemiologically relevant species.