Behavioural and physiological impacts of low salinity on the sea urchin Echinus esculentus.

Autor:	Barrett NJ; British Antarctic Survey, Natural Environment Research Council, Cambridge CB3 0ET, UK.; Department of Earth Sciences, University of Cambridge, Cambridge CB2 3EQ, UK., Harper EM; British Antarctic Survey, Natural Environment Research Council, Cambridge CB3 0ET, UK.; Department of Earth Sciences, University of Cambridge, Cambridge CB2 3EQ, UK., Last KS; The Scottish Association for Marine Science, Oban PA37 1QA, UK., Reinardy HC; The Scottish Association for Marine Science, Oban PA37 1QA, UK.; Department of Arctic Technology, The University Centre in Svalbard, N-9171 Longyearbyen, Norway., Peck LS; British Antarctic Survey, Natural Environment Research Council, Cambridge CB3 0ET, UK.
Jazyk:	angličtina
Zdroj:	The Journal of experimental biology [J Exp Biol] 2024 Jan 15; Vol. 227 (2). Date of Electronic Publication: 2024 Jan 16.
DOI:	10.1242/jeb.246707
Abstrakt:	Reduced seawater salinity as a result of freshwater input can exert a major influence on the ecophysiology of benthic marine invertebrates, such as echinoderms. While numerous experimental studies have explored the physiological and behavioural effects of short-term, acute exposure to low salinity in echinoids, surprisingly few have investigated the consequences of chronic exposure, or compared the two. In this study, the European sea urchin, Echinus esculentus, was exposed to low salinity over the short term (11‰, 16‰, 21‰, 26‰ and 31‰ for 24 h) and longer term (21, 26 and 31‰ for 25 days). Over the short term, oxygen consumption, activity coefficient and coelomic fluid osmolality were directly correlated with reduced salinity, with 100% survival at ≥21‰ and 0% at ≤16‰. Over the longer term at 21‰ (25 days), oxygen consumption was significantly higher, feeding was significantly reduced and activity coefficient values were significantly lower than at control salinity (31‰). At 26‰, all metrics were comparable to the control by the end of the experiment, suggesting acclimation. Furthermore, beneficial functional resistance (righting ability and metabolic capacity) to acute low salinity was observed at 26‰. Osmolality values were slightly hyperosmotic to the external seawater at all acclimation salinities, while coelomocyte composition and concentration were unaffected by chronic low salinity. Overall, E. esculentus demonstrate phenotypic plasticity that enables acclimation to reduced salinity around 26‰; however, 21‰ represents a lower acclimation threshold, potentially limiting its distribution in coastal areas prone to high freshwater input. Competing Interests: Competing interests The authors declare no competing or financial interests. (© 2024. Published by The Company of Biologists Ltd.)
Databáze:	MEDLINE
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