Feeding ecology of deep-sea seastars (Echinodermata: Asteroidea): a fatty-acid biomarker approach

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 255:193-206 (2003) - doi:10.3354/meps255193 Feeding ecology of deep-sea seastars (Echinodermata: Asteroidea): a fatty-acid biomarker approach Kerry L. Howell1,*, David W. Pond2, David S. M. Billett1, Paul A. Tyler1 1Southampton Oceanography Centre, European Way, Southampton SO14 3ZH, United Kingdom 2British Antarctic Survey, Madingley Rd., Cambridge CB3 0ET, United Kingdom *Email: kez1@soc.soton.ac.uk ABSTRACT: Fatty-acid biomarkers and stomach content analysis were used to investigate the diets of 9 species of deep-sea seastar. Polyunsaturated fatty acids were the most abundant categories of fatty acid contained in the total lipids of all species. They were dominated by 20:5 (n-3) and 20:4 (n 6), with 22:6 (n-3) present in much lower proportions. Monounsaturated fatty acids were also abundant, particularly 20:1 (n-13) and (n-9). Odd-numbered, branched-chain fatty acids and non-methylene interrupted dienes (NMIDs) were present in relatively high levels in all species. Cluster and multi-dimensional scaling (MDS) analyses of the fatty acid composition separated the seastar species into 3 trophic groups; suspension feeders, predators/scavengers, and mud ingesters. Suspension feeders showed greatest reliance on photosynthetic carbon as indicated by the abundance of fatty-acid biomarkers characteristic of photosynthetic microplankton. By contrast, mud ingesters were found to rely heavily on heterotrophic bacterial carbon, containing high percentages of 18:1 (n-7) and NMIDs. Predator/scavengers occupied a trophic position between the suspension feeders and mud ingesters. Zoroaster longicauda, an asteroid of unknown diet, had a similar fatty acid composition to the 3 suspension feeders, Freyella elegans, Brisingella coronata and Brisinga endecacnemos. While the suspension feeders are specialists on benthopelagic copepods, the preferred prey of Z. longicauda is unknown, but is likely to be very similar to that of the suspension feeders. Stomach content analysis revealed the diet of Z. longicauda also includes benthic echinoderms and crustaceans. KEY WORDS: Fatty acid biomarkers · Lipids · Diet · Asteroidea · Deep-sea ecology Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 255. Online publication date: June 24, 2003 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2003 Inter-Research.