Developmental and spatial variations in the diet signatures of hyperbenthic shrimp Nauticaris marionis at the Prince Edward Islands based on stable isotope ratios and fatty acid profiles

Richoux, Nicole B; Allan, E Louise; Froneman, P William

Title: Developmental and spatial variations in the diet signatures of hyperbenthic shrimp Nauticaris marionis at the Prince Edward Islands based on stable isotope ratios and fatty acid profiles
Creator: Richoux, Nicole B
Creator: Allan, E Louise
Creator: Froneman, P William
Date Issued: 2016
Date: 2016
Type: text
Type: article
Identifier: http://hdl.handle.net/10962/67923
Identifier: vital:29169
Identifier: https://doi.org/10.1016/j.csr.2016.02.0131
Description: Publisher version
Description: The caridean shrimp Nauticaris marionis is an ecologically important species in the benthic community around the sub-Antarctic Prince Edward Islands (PEI) as it represents a key prey item for a variety of top predators breeding on the islands. We hypothesized that the diet of N. marionis shifts during its development, and that spatial variability in food availability results in differentiation in the diet signatures of specimens collected from various locations of the shelf waters around the PEI. Specimens were collected from nine stations (depth range 70 to 240 m) around the PEI at inter-island shelf (from west to east: upstream, between and downstream) and nearshore regions during austral autumn 2009. Stable isotope and fatty acid data both revealed spatial and developmental variations in the shrimp diet. Nearshore shrimp were more 13C-enriched than those from the inter-island region, suggesting increased kelp detritus entered the food web in the nearshore regions. The shrimp showed increases in δ13C and δ15N signatures (and trophic position) with an increase in body size, resulting in distinctions between size classes that reflected shifts in their trophic niche through development. The fatty acid profiles similarly indicated distinctions in diet with increased shrimp size (in the deep regions), and spatial variability was evident in relation to region and depth. All shrimp contained large proportions of polyunsaturated and essential fatty acids, indicating that the quality of food consumed was similar between regions despite the diet variability. Our results provide new dietary information about a key species operating near the base of the food web at the highly productive PEI, and show that there were no areas of enhanced nutrition available to the shrimp. As such, there was no nutritional advantage to shrimp inhabiting any specific region around the PEI.
Format: 10 pages
Format: pdf
Publisher: Elsevier B.V.
Language: English
Relation: Continental Shelf Research
Relation: Richoux, N.B., Allan, E.L. and Froneman, P. W. (2016),Developmental and spatial variations in the diet signatures of hyperbenthic shrimp Nauticaris marionis at the Prince Edward Islands based on stable isotope ratios and fatty acid profile. Continental Shelf Research, 118, 1-10. https://doi.org/10.1016/j.csr.2016.02.013
Relation: Continental Shelf Research volume 118 number 1 10 2016 0278-4343
Rights: Elsevier B.V.
Rights: Use of this resource is governed by the terms and conditions of the National Library of South Africa Copyright Act (http://www.nlsa.ac.za/downloads/Copyright Act.pdf)

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SDG 02. Zero Hunger

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Richoux, Nicole Bertine (Assoc Prof)

Froneman, Pierre William (Prof)

RU Department of Zoology and Entomology

SDG 14. Life Below Water

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