Spatial distribution of epibenthic molluscs on a sandstone reef in the Northeast of Brazil

Abstract

<jats:p>The present study investigated the distribution and abundance of epibenthic molluscs and their feeding habits associated to substrate features (coverage and rugosity) in a sandstone reef system in the Northeast of Brazil. Rugosity, low coral cover and high coverage of zoanthids and fleshy alga were the variables that influenced a low richness and high abundance of a few molluscan species in the reef habitat. The most abundant species were generalist carnivores, probably associated to a lesser offer and variability of resources in this type of reef system, when compared to the coral reefs. The results found in this study could reflect a normal characteristic of the molluscan community distribution in sandstone reefs, with low coral cover, or could indicate a degradation state of this habitat if it is compared to coral reefs, once that the significantly high coverage of fleshy alga has been recognized as a negative indicator of reef ecosystems health.</jats:p>

Invertebrates Diversity of Merta Segara and Nyangnyang Beach: Comparison Study of Two Beaches with Different Characteristics

“…It was consistent with a previous study which showed the dominancy by several taxa in another rocky intertidal shore [6]. In the other hand, low density and evenly distributed of invertebrates species were commonly characteristic of sandy shore with seagrass bed [44].…”

Gulf of Mannar Island coral reef associated gastropods assemblages: Distribution and diversity pattern

“…The higher abundance of few species found on the Maracajaú reef, a result also observed on Caribbean reefs, may be associated to environmental stress [44]. The low values for molluscan density and richness in the profiles of seagrass and sandy bottom habitats probably reflect the behavior of many individuals that habitually bury in the substrate and are not visible to the naked eye [46]. Our study supports the hypothesis that gastropods, like other coral reef populations, are regulated by density-independent factors, but not the hypothesis that they are nonequilibrium assemblages; they may be in equilibrium with their predators [47] and early post-settlement mortality [48,49].…”

The forgotten reefs: benthic assemblage coverage on a sandstone reef (Tropical South-western Atlantic)

“…Data on benthic assemblages in underwater sandstone reefs, especially in TSA ( sensu Spalding et al ., 2007), are still very scarce. Most of the information is focused on vagile or semi-vagile organisms (Martínez et al ., 2012; Freitas & Lotufo, 2015; Galvão Filho et al ., 2015), and information on ecosystem engineering species ( sensu Jones et al , 1997) is almost non-existent (Rabelo et al ., 2015).…”

“…Sandstone reefs provide shelter and food for commercial species (Martínez et al ., 2012; Freitas & Lotufo, 2015), and they are important touristic areas in TSA. Because of this ecological and socioeconomic importance, we urgently need to collect information on the benthos of these formations.…”