In:
Marine Ecology, Wiley, Vol. 36, No. S1 ( 2015-08), p. 18-34
Abstract:
For the last few decades, trophic ecology has usually been investigated by using stable isotopes. However, the isotopic signatures of potential food sources in hydrothermal vent ecosystems are often unknown and so their relative contribution to the consumers’ diet, as well as resource partitioning, are then difficult to estimate. Here, we used a recent B ayesian mixing model (stable isotope analysis in R , SIAR ) based on δ 13 C and δ 15 N to estimate the contribution of multiple food sources to the diet of eight vent gastropods that can reach high densities at hydrothermal vents ( L epetodrilus elevatus , L epetodrilus pustulosus , L epetodrilus ovalis , E ulepetopsis vitrea , C yathermia naticoides , P eltospira delicata , P eltospira operculata and R hynchopelta concentrica ). These species, known as primary consumers (mostly bacterivores and detritivores), were sampled on the S outh‐ E ast P acific R ise at 17°25′ S and the N orth‐ E ast P acific R ise at 9°50′ N and 12°50′ N. Several potential food sources were sampled according to the gastropod habitat on the chimney wall, or mussel beds (proxies of G ammaproteobacteria form I R ubis CO , G ammaproteobacteria form II R ubis CO and E psilonproteobacteria , biofilms of siboglinid and alvinellid tubes, biofilms of mussel shells and particulate organic matter). Some of these microbial and detrital sources were confirmed as present in the gut content of some small specimens by transmission electron microscopy. Distinct stable isotopic signatures of the potential food sources allowed calculation of their relative contributions to primary consumers’ diets. This revealed that gastropod species living on siboglinid or bathymodiolin habitats are usually generalists, feeding on various pools of microbial or detrital origins. For a particular habitat, sympatric gastropod species partition the food sources, thus avoiding being in competition. Only for the alvinellid habitat P eltospira spp. appeared to be more specialists as the choice of food sources is more reduced.
Type of Medium:
Online Resource
ISSN:
0173-9565
,
1439-0485
DOI:
10.1111/maec.2015.36.issue-S1
Language:
English
Publisher:
Wiley
Publication Date:
2015
detail.hit.zdb_id:
2020745-1
detail.hit.zdb_id:
225578-9
SSG:
12
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