Coral reef development influences the spatial pattern of echinoderms in the Central Mexican Pacific

Habitat heterogeneity is one of the main factors influencing the dynamics in benthic marine communities. This work assessed the influence of different degrees of coral development − i.e., coral patches and coral communities − on the spatial patterns of echinoderm assemblage in the central Mexican Pacific. The fieldwork was conducted in September 2019 at six sites with different coral reef development. The composition and abundance of echinoderm species and the coverage of corals and other benthic components (substrate characteristics) were quantified at each site. Different community attributes (species richness and Shannon diversity), species similarity patterns, and their relationships with the benthic habitat structure were also surveyed. The results suggested that the echinoderm assemblage of the southern coast of Jalisco includes species that are representative in comparable ecosystems of the eastern tropical Pacific, highlighting the sea urchin Diadema mexicanum and the sea cucumber Pseudocnus californicus as the most abundant species. The echinoderm assemblage structure evidenced dissimilarities among sampling sites and between site conditions (coral patches vs. coral communities), caused mainly by the different abundance of the sea urchin P. californicus, and the sea urchins D. mexicanum, Toxopneustes roseus, Eucidaris thouarsii , and Echinometra vanbrunti. The coral Pocillopora was associated with coral patches, while the massive coral Porites was mainly related to coral communities. These coral species and articulated calcareous algae were the most relevant environmental variables explaining the spatial variation in the echinoderm assemblage. The highest richness, abundance, and diversity of echinoderms were found in coral community habitats . This study indicates that different degrees of coral development, such as coral patches and coral communities, influence the spatial patterns of echinoderm assemblage.