A review on macrobenthic trophic relationships along subtropical sandy shores in southernmost Brazil

Abstract

PINOTTI, R.M., MINASI, D.M., COLLING, L.A., BEMVENUTI, C.E. A review on macrobenthic trophic relationships along subtropical sandy shores in southernmost Brazil.http://dx.doi.org/10.1590/1676-06032014006914Abstract: Main trophic relationships that occur along the exposed sandy shores in southernmost Brazil (,336 S) are established taking into account several biological compartments operating at morphodynamically distinct environments. Beaches are predominantly of the intermediate type but some stretches of coastline are truly dissipative (Cassino Beach) or tending-to-reflective (Concheiros Beach), presenting thus diverse biological compartments and inhabitant macrobenthic assemblages. Dense concentrations of the surf-zone diatom Asterionellopsis glacialis are responsible -at least for the intermediate shorelines -for the most year-round primary production, sustaining several consumers up to tertiary level. Among them, bivalves Amarilladesma mactroides, Donax hanleyanus and the hippid crab Emerita brasiliensis can account for more than 95% of all the surf-zone secondary production, in addition to the elevated biomass of the suspension-feeder polychaete Spio gaucha and the scavenger isopod Excirolana armata. Crabs, whelks, carnivorous polychaetes, seabirds and surf-zone fishes may also be present and occupy superior trophic levels depending on the beach morphodynamics. Based on the high species richness, abundance and the role of macrobenthic fauna in transferring matter and energy to seabirds and the surf-zone fish assemblages, we address this important issue on the Southwestern Atlantic ecology. Conservation efforts should be implemented for the southernmost Brazilian sandy shores, at least for those non urbanized areas. Keywords: exposed beach, intermediate states, primary production, secondary consumers, conservation.PINOTTI, R.M., MINASI, D.M., COLLING, L.A., BEMVENUTI, C.E. Revisão sobre as relações tróficas macrozoobentônicas ao longo da costa arenosa subtropical do extremo sul do Brasil. Biota http://dx.doi.org/10.1590/1676-06032014006914Resumo: As principais relaçõ es tró ficas observadas ao longo da costa arenosa exposta do extremo sul do Brasil (,336 S) sã o estabelecidas levando-se em consideraçã o os vá rios compartimentos bioló gicos que operam em ambientes morfodinamicamente distintos. Estas praias sã o predominantemente do tipo intermediá rio, embora alguns trechos sejam dissipativos (Praia do Cassino) ou apresentem tendências reflectivas (Praia dos Concheiros), possuindo compartimentos bioló gicos diversificados e associaçõ es macrobentô nicas residentes. Densas concentraçõ es da diatomá cea Asterionellopsis glacialis sã o responsá veis -pelo menos para as praias intermediá rias -por grande parte da produtividade primá ria anual, sustentando vá rios consumidores até o nível terciá rio. Entre estes, os bivalves Amarilladesma mactroides, Donax hanleyanus e o crustá ceo Emerita brasiliensis sã o responsá veis por mais de 95% de toda a produçã o secundá ria da zona de surfe, em adição à elevada biomas...

Predator Diet and Trophic Position Modified with Altered Habitat Morphology

“…Better documentation of ghost crab behavior and accessibility to resources, including the consumer’s ability to forage in strong wave surge, fine or densely-packed sediments and macrophyte wrack is desirable; such information will improve our working model and help evaluate the assumption that ghost crabs have access to all food resources on every beach. Additionally, investigations of ghost crab feeding in response to the presence of their own native (herons, gulls, raccoons) and introduced predators (foxes, feral cats, dogs) as well as competitors (plovers, sandpipers, and turnstones) may be informative [ 11 , 31 , 43 , 85 , 86 , 90 ] and may help explain the strong patterns of highest ghost crab density being recorded on beaches of intermediate width reported here. However, despite these limitations, our study provides new details on diets and trophic position given our use of longer-term, integrated measures of ghost crab diets (stable isotopes) and a dynamic food web approach.…”

“…In contrast, ghost crabs may avoid ingesting stomach contents of the comparatively larger mole crabs as they can select muscle tissue [ 37 ] which may be difficult when consuming either the smaller amphipods or coquinas. In addition, ghost crabs may supplement diets by microphagous depositing feeding when beaches become wider and less physically dynamic [ 49 , 85 ]. Higher values of TP (> 3) of ghost crabs from some beaches may indicate the use of carrion of secondary and tertiary consumers or eggs (e.g.…”

Distribuição Espacial Da Macrofauna Bêntica Da Praia Da Avenida – Ilhéus-Ba, Brasil

“…A ocorrência de insetos no nível superior de praias arenosas pode estar diretamente associada ao depósito de detritos, de origem natural ou antrópica. Essas acumulações densas de depósitos orgânicos representam uma importante fonte de alimento não só para insetos, mas também para alguns crustáceos detritívoros (GANDARA -MARTINS et al, 2010;ODEBRECHT et al, 2014;PINOTTI et al, 2014). Na praia estudada o nível médio superior está localizado a pequena distância da vegetação de porte herbáceo-arbustivo.…”

“…É também comum a presença de necrófagos como o crustáceo isópodo Excirolana braziliensis. Além disso, devido a densas acumulações de diatomáceas e detritos orgânicos, formando manchas escuras no nível superior da praia, podem ser encontrados coleópteros terrestres (ODEBRECHT et al 2014;PINOTTI et al 2014).…”

Potential kleptoparasitism-scavenging interactions between crabs and shell-boring gastropods feeding on bivalve prey: a global survey

“…This was because this survey used a database that relies on users to upload reports of species interactions (Poelen et al 2014), and is thus subject to the users knowledge since, if only users with knowledge of or access to information on certain taxonomic groups or geographic regions have contributed to the database, there will be gaps in the information therein. For example, no records of bivalve consumption or consumption of the same bivalves as any crab taxon were found for several gastropod groups (see Materials and methods), but given the wide diversity of crabs, gastropods, and bivalves in the world and the fact that some members of these groups are known to consume bivalves and/or compete with crabs for other types of shared food (e.g., Powers & Kittinger 2002, Chiu et al 2011, Pinotti et al 2014, Davenport et al 2015, such gaps more likely reflect the limitations of the database than the actual absence of trophic overlap (and potential K-S interactions) between these gastropods and crabs. Therefore, while the species groups identified herein are systems in which crab-gastropod K-S interactions likely occur, other crab and shell-boring gastropod taxa that feed on the same bivalves beyond those identified in this survey should be investigated for the occurrence of these interactions as well.…”