Premium
Stable carbon and nitrogen ratios in the sand smelt from a Mediterranean coastal area: feeding habits and effect of season and size
Author(s) -
Vizzini S.,
Mazzola A.
Publication year - 2002
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1111/j.1095-8649.2002.tb02443.x
Subject(s) - biology , trophic level , smelt , benthic zone , ecology , isopoda , predation , mediterranean climate , detritivore , isotope analysis , zoology , fishery , crustacean , fish <actinopterygii>
Enriched δ 13 C values (annual average – 11.2‰) suggest that in the study site (Stagnone di Marsala, Italy) the sand smelt Atherina boyeri exploited benthic prey throughout the year. In particular, Mysidacea and Isopoda seemed to dominate the diet. Stomach content data from the literature was in partial agreement with the present isotopic analysis suggesting that, while Mysidacea and Isopoda are exploited by A. boyeri , Copepoda Harpacticoida and Amphipoda are the dominant food items of the sand smelt diet. Several hypotheses are proposed to explain such partially different results from the two techniques. Both season and size influenced the δ 13 C and δ 15 N values of A. boyeri . Although throughout the sampling year, A. boyeri showed very enriched δ 13 C and δ 15 N values consistent with a diet based on benthic resources, it showed significant seasonal differences in both nitrogen and carbon isotope ratios. Such a finding suggests that the food preferences of A. boyeri undergo small seasonal differences, probably as a consequence of prey availability. Size also affected the isotopic composition of the sand‐smelt indicating that this species shows ontogenetic diet shifts in the study site. Compared with other Mediterranean trophic data of the sand smelt these results substantiate the great adaptability of A. boyeri to the local environmental resources and its trophic plasticity.