Patterns of trophic resource use among deep-sea shrimps in the Northern Benguela current ecosystem, Namibia

Abstract

The marine waters of Northern Benguela Ecosystem (NBE) off the Namibia support high abundances of different marine species. Seven shrimp species: Aristeus varidens, Funchalia woodwardi, Glyphus marsupialis, Heterocarpus grimaldi, Solenocera africana, Plesionika martia and Parapeneus longirostris, form an important trophic linkage between primary consumers and other trophic levels in the NBE. This study examined their trophic resource use patterns using their stable isotope measurements (δ15N, δ13C). Results indicated that although their trophic niche overlapped, there were some variations in their carbon sources (δ13C) and feeding positions (δ15N). Heterocarpus grimaldi fed at a higher trophic position, while P. longirostris fed at the lowest position. Latitude, body size and depth contributed to the variations observed in isotopic values of these crustaceans. This study represents the first attempt at understating trophic resource use patterns of crustaceans in the NBE using stable isotopic measurements. Further research is needed to investigate if the trophic interactions observed in this study are consistent across time and space.