Deposit Feeding and Sediment

Author(s)
Rainer M.W. Amon, Gerhard J. Herndl
Abstract

Abstract. The feeding of the epibenthic deposit‐feeder Holothuria tubulosa GMELIN and its influence on sediment metabolism was investigated from February 1988 to February 1989. Water samples, specimens of H. tubulosa, and samples of freshly egested feces were taken by SCUBA diving in a 5 m deep seagrass bed at the Island of Ischia in the Gulf of Naples (Italy). Particulate organic carbon (POC), particulate organic nitrogen (PON), total particulate carbohydrates (PCHO), and bacterial biomass exhibited higher values in the foregut than in the surrounding sediment. Even the freshly egested feces were richer in the organic components than the sediment. The percentage of growing bacterial cells increased from 4.1 % in the sediment to 12.2 % in the foregut and declined to 11.6 % in the hindgut and 6.2 % in freshly egested feces. On an annual average, absorption efficiency was highest for bacteria (x = 71%); for PON we calculated a mean absorption efficiency of 20.9%, for PCHO 19.5%. It was estimated that bacterial biomass supplied between 4 and 25 % of the respiratory carbon demand of H. tubulosa. We present evidence that the feeding activity of H. tubulosa stabilizes the bacterial community in the sediment. Furthermore, our data indicate that H. tubulosa reacts quickly to changing conditions, such as sedimented phytoplankton blooms.

Organisation(s)
Functional and Evolutionary Ecology
External organisation(s)
Universität Wien
Journal
Marine Ecology
Volume
12
Pages
163-174
No. of pages
12
ISSN
0173-9565
DOI
https://doi.org/10.1111/j.1439-0485.1991.tb00250.x
Publication date
01-1991
Peer reviewed
Yes
Austrian Fields of Science 2012
106021 Marine biology
Keywords
ASJC Scopus subject areas
Ecology, Evolution, Behavior and Systematics, Aquatic Science, Ecology
Portal url
https://ucris.univie.ac.at/portal/en/publications/deposit-feeding-and-sediment(c9121944-4ba1-4ac4-8aea-fc3732f22908).html