Habitat heterogeneity shapes intertidal gastropod assemblages on Samai Island, western New Guinea
In: Thalassas. Universidad de Vigo: Vigo. ISSN 0212-5919; e-ISSN 2366-1674, meer
|  |
| Author keywords |
Gastropod assemblages · Habitat heterogeneity · Community assembly · Environmental filtering · Western New Guinea |
| Auteurs | | Top |
- Binur, R.
- Bakri, I.
- Sinuraya, S.
- Mogea, R.A.
|
|
|
| Abstract |
Habitat heterogeneity is widely recognized as a key driver of biodiversity and community assembly in tropical coastal ecosystems, yet its effects on gastropod assemblages remain poorly understood across many regions of New Guinea. This study examined gastropod diversity, community structure, species overlap, abundance, density, spatial distribution, and environmental drivers across four intertidal habitats (Muddy-sand, Sandy-seagrass, Coral rubble, and Mixed) on Samai Island, western New Guinea. Gastropods were surveyed using standardized transects and quadrats, and community patterns were analyzed with diversity indices, rarefaction–extrapolation, similarity analyses, density and dispersion metrics, PERMANOVA, and distance-based redundancy analysis (dbRDA). A total of 3,270 individuals, representing 74 species and 21 families, were recorded. Mixed habitats had the highest species richness (49 species), density, and number of habitat-specific taxa, whereas Muddy-sand had the highest Shannon diversity (H′ = 3.14) and evenness (J′ = 0.87). Species overlap and similarity analyses revealed distinct habitat-associated assemblages, with Sandy-seagrass exhibiting the greatest compositional differentiation. Strombidae dominated overall abundance (47.74%), largely driven by Strombus luhuanus (39.87% of all individuals), while several Conus species characterized Muddy-sand habitats. Gastropod densities differed significantly across habitats, and spatial analyses indicated predominantly aggregated distributions. Environmental gradients, particularly salinity, temperature, dissolved oxygen, and pH, contributed to assemblage differentiation, although substrate heterogeneity emerged as the primary factor structuring communities. These findings demonstrate that habitat complexity and environmental filtering jointly regulate gastropod community assembly and highlight the importance of conserving interconnected intertidal habitat mosaics to maintain biodiversity and ecosystem functioning in western New Guinea. |
|
