Macrocrustaceans associated with reefs of Phragmatopoma caudata Krøyer in Mörch, 1863 (Polychaeta: Sabellariidae) and rocky shore in the Northeastern Brazil

Abstract

Ecosystem engineering species create, modify, and/or maintain the characteristics of the environment. The polychaete Phragmatopoma caudata builds large sand reefs in the intertidal region of the Brazilian coast with high structural complexity, favoring the increase of diversity and interactions among the species associated. However, there are no studies concerning the association of polychaetes with crustacean macrofauna in the northeastern Brazil ecoregion, leaving an information gap on baseline biodiversity. Our aim was to analyze the effect of P. caudata colonies (PC) on the local diversity of macrocrustaceans compared to the rocky shore (RS) microhabitat. Monthly collections were carried out in low tide from September 2015 to August 2016 on 10 × 10 m quadrants for fauna and environmental variables (temperature and salinity) samples. In each microhabitat, the capture effort was two hours by two researchers. We collected 3,390 individuals, 60% associated with the colonies of PC and 40% with the RS. The PC obtained higher Shannon diversity, Pielou evenness and species richness coupled with milder water temperature and salinity conditions (minor air exposure during tide), compared to the RS that obtained greater species dominance and more extreme abiotic conditions (major air exposure). The Porcellanidae family stood out because all its species were highly abundant and had high occurrence in the colonies. The tropical Brazil porcelain crab Pachycheles greeleyi was dominant in both microhabitats (major dominance in PC). The structural complexity in the reefs of PC promoted higher availability of niches for the species, as more shelter for the resident species and refugium for temporary species with preference for more complex microhabitats. Conservation managers should prioritize the health of these colonies and subsequent species that constitute important ecosystemic and fishery resources.

Macrobenthic community of an estuarine tidal flat on the Amazon coast: spatial variations and presence of polychaetes tubes

“…In general, there is a positive influence on the species richness and abundance of the fauna associated with these tubes (Santos & Aviz, 2018 The literature on the fauna associated with polychaetes tubes is impressive, especially regarding the temperate latitudes where they are widespread (e.g., Woodin, 1978;Bell & Coen, 1982a, b;Callaway, 2003;Dubois et al, 2006;Thomsen et al, 2011;Jones et al, 2018). However, unlike intertidal habitats at temperate latitudes, there are few studies regarding the fauna associated with polychaetes tubes in tropical regions (e.g., Fournier, 2010;Guilherme et al, 2011;Ataide et al, 2014;Aviz et al, 2018Aviz et al, , 2021Lane-Medeiros et al, 2021). In addition, there is virtually no data from tropical regions, especially for the Amazon coast, about studies regarding the fauna associated with D. cuprea tubes, even though this species is common in intertidal estuarine areas and protected beaches of the region (Santos & Aviz, 2018), thus providing limited information on community structure in Amazon coastal areas.…”