Kolasinski J. auteur aut IRD Frouin P. auteur aut IRD Sallon A. auteur aut IRD Rogers K. auteur aut IRD Bruggemann H. J. auteur aut IRD Potier Michel auteur aut IRD text journalArticle eng text/pdf reformatted digital access We analyzed stomach contents and muscle isotopic composition (delta C-13, delta N-15) of yellowstripe goatfish Mulloidichthys flavolineatus from a coral reef to investigate size-related dietary changes and resource or habitat partitioning. Juveniles (< 12 cm total length [TL]), young adults (12 <= TL < 17 cm) and adults (>= 17 cm TL) showed a high diet overlap, especially between juveniles and young adults. According to stomach contents analysis, M. flavolineatus widens its prey spectrum with increasing size from a common prey pool that includes polychaetes, tanaids and harpacticoid copepods. We observed a significant increase in delta C-13 values (from -17.1 +/- 0.5 parts per thousand for juveniles to -10.7 +/- 0.8 parts per thousand for adults), which were correlated to fish size. Adults (delta N-15 mean of 11.1 +/- 1.8 parts per thousand) were one trophic level above juveniles and young adults (7.7 +/- 0.5 and 7.4 +/- 0.5 parts per thousand, respectively). These patterns of isotopic changes confirmed ontogenetic dietary shifts. However, trophodynamics can be influenced by physiological factors such as growth and sexual maturity. M flavolineatus shift from a pelagic to a macrobenthic diet, which is equilibrated at the adult stage. Results from combined stomach contents (prey volume) and stable isotope analyses suggested a dominant contribution of polychaetes (macrofauna), possibly through selective feeding. Conversely, on the basis of prey volume and stable isotope data, meiofauna did not feature significantly in the diet despite their high abundance in stomachs. Two adult groups were distinguished based on their delta N-15 values (11.9 +/- 0.8 and 7.8 +/- 0.6 parts per thousand), indicating possible stage-specific partitioning in habitat use inside the reef. specialized Yellowstripe goatfish Ontogenetic diet shift Stomach contents Stable isotopes Mixing model Southwestern Indian Ocean 036 386 181-195 2009 0171-8630 https://www.documentation.ird.fr/hor/PAR00003941 10.3354/meps08081 0171-8630 [F B010081690] https://www.documentation.ird.fr/hor/PAR00003941 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers21-04/010081690.pdf IRD - Base Horizon / Pleins textes 2009-09-01 2021-04-21 PAR00003941 fre