Grazing in the dark: A behavioural adjustment in a population of the black sea urchin Arbacia lixula

In Mediterranean rocky shores, the black sea urchin Arbacia lixula is often associated with communities dominated by encrusting corallines, devoid of fleshy algae. While it is commonly known as a diurnal herbivore, this species also migrates at night from hidden to more exposed habitats. Here, we pr...

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Detalhes bibliográficos
Autores: Mariani, Simone, Pinedo, Susana, Jordana, E., Cefalì, Maria Elena, Torras, Xavier, Bagur, Marina, Verdura, Jana, Ballesteros, Enric
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2023
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositório:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/349187
Acesso em linha:http://hdl.handle.net/10261/349187
https://api.elsevier.com/content/abstract/scopus_id/85169612565
Access Level:Acceso aberto
Palavra-chave:Antipredator responses
Mediterranean Sea
overgrazing
sea urchin barrens
Descrição
Resumo:In Mediterranean rocky shores, the black sea urchin Arbacia lixula is often associated with communities dominated by encrusting corallines, devoid of fleshy algae. While it is commonly known as a diurnal herbivore, this species also migrates at night from hidden to more exposed habitats. Here, we provide the first experimental evidence of an adjustment to a predominant nocturnal behaviour in a population of A. lixula. Sea urchin densities changed from nearly zero during daytime to more than 16 urchins m−2 at night in treatment plots where the sea urchins were removed. We suggest that the observed behaviour was triggered by our experimental manipulations and was a response to the presence of dead conspecifics and small predatory fishes attracted by the urchin culling. Further research is needed to assess whether our findings can be generalised to the behaviour of A. lixula in areas where sea urchins are under strong pressure from diurnal predators. In these cases, it is important to perform sea urchin density counts at night to avoid misleading assessments about the herbivore pressure in a littoral area.