Elucidating the trophodynamics of four coral reef fishes of the Solomon Islands using delta N-15 and delta C-13

作者：Greenwood N D W^*; Sweeting C J; Polunin N V C

来源：Coral Reefs, 2010, 29(3): 785-792.

DOI：10.1007/s00338-010-0626-1

• Trophic level
• Ontogenetic diet shifts
• Coral reefs
• Stable isotope analysis

Size-related diet shifts are important characteristics of fish trophodynamics. Here, body size-related changes in muscle delta N-15 and delta C-13 of four coral reef fishes, Acanthurus nigrofuscus (herbivore), Chaetodon lunulatus (corallivore), Chromis xanthura (planktivore) and Plectropomus leopardus (piscivore) were investigated at two locations in the Solomon Islands. All four species occupied distinct isotopic niches and the concurrent delta C-13' values of C. xanthura and P. leopardus suggested a common planktonic production source. Size-related shifts in delta N-15, and thus trophic level, were observed in C. xanthura, C. lunulatus and P. leopardus, and these trends varied between location, indicating spatial differences in trophic ecology. A literature review of tropical fishes revealed that positive delta N-15-size trends are common while negative delta N-15-size trends are rare. Size-delta N-15 trends fall into approximately equal groups representing size-based feeding within a food chain, and that associated with a basal resource shift and occurs in conjunction with changes in production source, indicated by delta C-13. The review also revealed large scale differences in isotope-size trends and this, combined with small scale location differences noted earlier, highlights a high degree of plasticity in the reef fishes studied. This suggests that trophic size analysis of reef fishes would provide a productive avenue to identify species potentially vulnerable to reef impacts as a result of constrained trophic behaviour.

• 出版日期2010-9