The effect of habitat structural complexity on gastropods in an arid mangrove wetland

Abstract

Structural complexity of mangrove forests is thought to provide critical habitats for a variety of invertebrates. We studied the influence of habitat structure and sampling time on the gastropod diversity in Khuran mangrove ecosystem in the Persian Gulf. Sampling was conducted in two successive years (February and June 2018, February and June 2019) at two mangrove habitats i.e., pneumatophore zone and mudflats. The gastropod assemblages were characterized by the dominance of specific taxa and low species richness. In total, 18 taxa were identified, including 14 species occurring in the mangrove forest and 16 species in the mudflats. Assimineidae dominated the assemblages in both mangrove habitats. Four species (Mitrella blanda, Mitrella cartwrighti, Pellamora densilabrum, Pseudominolia sp.) were found only in mudflat habitats, while two species (Bakawan rotundata, Peronia verruculata) were found only in pneumatophore zones. The gastropod assemblage structure differed significantly between habitats and sampling dates. Of the environmental variables measured, distance-based linear models revealed that total organic carbon (TOC), and total nitrogen (TN) best explained the variation in gastropod assemblage structure. We suggest that conservation efforts should focus not only on preserving mangrove forests, but also upon protecting their adjacent bare mudflats as they provide habitat for various mangrove fauna.