High intraspecific variability in the diet of a deep-sea nematode: Stable isotope and fatty acid analyses of Deontostoma tridentum on Chatham Rise, Southwest Pacific

摘要: Small deep-sea organisms may exhibit a high degree of intraspecific variability in diet due to their ability exploit wide range food sources and patchiness availability. Trophic interactions small benthic organisms, however, remain poorly understood. Here we describe spatial variation diet/trophic level the common nematode Deontostoma tridentum on Chatham Rise, Southwest Pacific, using carbon nitrogen stable isotope fatty acid analyses. We also analysed sediment organic matter (SOM) compared isotopic composition D. other suprabenthic macrofaunal taxa with variety feeding modes. Variability δ13C δ15N signatures was both among sites within single site southern flank Rise. Among-site SOM not sufficient explain signatures. The presence positive correlation between (both sites) could suggest that differences trophic is cause behind this variation. Nitrogen data 1–3 levels species, which reflect prey availability, body size, or habitat (benthic versus epizoic). Nematode values exceeded those all investigated, including predators, but reasons for enrichment unclear. did vary substantially characterised by relatively 18:1n9 (15–20%) polyunsaturated acids (PUFAs; ~22%). Although limited inferences can be made based potential impacts non-dietary factors, PUFAs indicate represents good source these essential nutrients higher levels. In conclusion, our results show (1) some diet, (2) nematodes an important larger animals environments, where quality low.