Spatiotemporal dynamics of the molluscan community associated with seagrass on the western equatorial Atlantic

Abstract

This study aimed to qualitatively and quantitatively analyse the molluscan assemblages associated with a Halodule wrightii seagrass bed in a rarely studied area within a conservation unit in north-eastern Brazil. Seasonal and spatial changes in several seagrass meadow characteristics, including sediment, were evaluated to explain temporal and spatial variations in the molluscs found there. The molluscan community differed in its structure among periods and meadows, as well as in the composition of its infaunal and epifaunal assemblages. The results of this study indicated that molluscs are affected by the particular characteristics of a seagrass meadow, especially by its location in the intertidal zone, more than by the area of the meadow. Molluscs were also affected by other characteristics of the seagrass meadow, such as above-ground biomass and shoot density. Changes in all molluscan assemblages were also mediated by differences among months and seasons in this region of the western equatorial Atlantic, but not by seasonal changes of the meadow. The studied meadow was found to be one of the densest in Brazil, which has considerable importance to its associated fauna.

Species diversity, trophic structure, and taxonomic distinctness of molluscan assemblages associated with Sargassum beds in a historically impacted bay

“…Other well‐represented trophic groups here were suspension feeders, ectoparasites, and carnivores/scavengers. This pattern of trophic distribution is similar to other marine vegetated habitats in Brazilian coast and in other localities (Antit et al, 2013; Cavalcante et al, 2019; Longo et al, 2014; Urra et al, 2013). According to Duarte et al (2020), macroalgal morphology has a great influence on functional diversity of associated molluscan assemblages, especially considering the diversity of feeding strategies, which may explain why many different trophic categories are represented by a high number of species in Sargassum habitats since this brown macroalga is considered to have a highly complex morphology (Chemello & Milazzo, 2002).…”

Neritidae (Gastropoda, Neritimorpha) From the Malacological Collection Prof. Henry Ramos Matthews of the Universidade Federal Do Ceará, Brazil

“…At CMPHRM, there are specimens of S. viridis (nine lots) from northeast Brazil (Piauí and Ceará States). In the Brazilian Province, this species was already recorded in Piauí (Barra Grande Beach), Ceará, Paraíba (Formosa beach), Bahia (Itaparica Island), and São Paulo (Porchat Island) (Rios, 2009;Rocha-Barreira et al, 2017;Cavalcante et al, 2019). According to Eichhorst (2016) and WoRMS data (WOrMS Editorial Board 2020), S. viridis is an amphi-atlantic species, occurring from Florida (USA) to Brazil, including Caribbean, in the Western Atlantic and from the Canary Islands to Senegal, comprising the Mediterranean in the Eastern Atlantic.…”

“…Cristiane Xerez Barroso, Cristina de Almeida Rocha Barreira, Helena Matthews-Cascon The third neritid genus deposited in the CMPHRM and found in the Brazilian Province was Smaragdia, represented by S. viridis, an herbivorous species that eats marine angiosperms upon which it lives (Rueda et al, 2009;Cavalcante et al, 2019). At CMPHRM, there are specimens of S. viridis (nine lots) from northeast Brazil (Piauí and Ceará States).…”

Primeiro Levantamento Da Biodiversidade De Ascídias Em Recifes De Arenito Da Apa Delta Do Parnaíba (Brasil Equatorial) E Variações Dentro E Entre Recifes

“…Sobre a variação na composição específica entre os recifes, uma vez que os recifes abrigam conjuntos de espécies muito distintos entre si, conclui-se que ações de preservação devem buscar minimizar o impacto antropogênico nos recifes da APADP como um todo, ao invés de ações localizadas que priorizem alguns poucos recifes. É importante ressaltar também que decisões no que tange à conservação não podem ser tomadas somente com base na biodiversidade de ascídias, pois os serviços ambientais prestados pelo recife do MB, que apresentou baixa riqueza de ascídias, incluem a sua associação a pradarias que abrigam uma fauna rica (Cavalcante et al, 2019) e alimentam uma população de peixe-boi (Ciotti, 2012). Vale ressaltar também que as praias da região são arenosas e que esses recifes representam, portanto, manchas de substrato rochoso na paisagem regional.…”