title: Motoric impairment following manganese exposure in asteroid echinoderms.
abstract: In the oceans, naturally occurring manganese (Mn) is released from the sediments during events of hypoxia. While neuro- and immuno-toxic effects of bioavailable manganese are well documented for crustaceans, studies of similar effects of manganese on other marine invertebrates are comparatively few. Here, we developed a new functional test "the repeated turning assay" to investigate if manganese exposure at ∼12 mg L(-1) affected motoric behaviour of two asteroid echinoderms, the Common sea star, Asterias rubens, and the Black brittle star, Ophiocomina nigra. By measuring of the turning-over capacity, from dorsal to ventral position, after one and two weeks of manganese exposure, we showed that for both species Mn exposure significantly delayed the ability to turn. After a recovery period of two weeks, the capacity of turning-over was not restored to that of unexposed animals neither for A. rubens nor for O. nigra. Further investigation of sea stars showed that Mn accumulated ∼5 fold in the tube feet, organs involved in their turning-over activity, and the high concentration remained after the recovery period. In the tube feet we also recorded an increased activity of acetylcholinesterase (AChE), here used as a proxy for neuromuscular disturbances. The results indicated that Mn induces neuromuscular disturbance in echinoderms which is important news, given that previous studies have concluded that adult echinoderms are relatively tolerant to Mn.
authors.affiliation: Sven Lovén Centre for Marine Sciences-Kristineberg, University of Gothenburg, Box 566, SE-451 78 Fiskebäckskil, Sweden.
authors.forename: Helen Nilsson
authors.initials: HN
authors.lastname: Sköld
authors.affiliation: Dept Biological and Environmental Sciences, University of Gothenburg, Kristineberg 566, SE-451 78 Fiskebäckskil, Sweden.
authors.forename: Susanne P
authors.initials: SP
authors.lastname: Baden
authors.affiliation: Dept Biological and Environmental Sciences, University of Gothenburg, Kristineberg 566, SE-451 78 Fiskebäckskil, Sweden.
authors.forename: Jakob
authors.initials: J
authors.lastname: Looström
authors.affiliation: Dept Biological and Environmental Sciences, University of Gothenburg, Kristineberg 566, SE-451 78 Fiskebäckskil, Sweden.
authors.forename: Susanne P
authors.initials: SP
authors.lastname: Eriksson
authors.affiliation: The Royal Swedish Academy of Sciences, Kristineberg 566, SE-451 78 Fiskebäckskil, Sweden; Dept Natural Science, Kristianstad University, SE-291 88 Kristianstad, Sweden. Electronic address: bodil.hernroth@kva.se.
authors.forename: Bodil E
authors.initials: BE
authors.lastname: Hernroth
mesh_terms: D000818:Animals; D047271:Asterias / Q000187:drug effects*; D008345:Manganese / Q000633:toxicity*; D009043:Motor Activity / Q000187:drug effects; D009792:Oceans and Seas; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical; D008345:Manganese
keywords: Acetylcholinesterase; Asterias rubens; Manganese exposure; Neuromuscular behaviour; Ophiocomina nigra; Turning assay