Liedke, Ana M. R.
Bonaldo, Roberta M.
Ferreira, Carlos E. L.
Nunes, Lucas T.
Burig, Ana P.
Oliveira-Santos, Luiz Gustavo R.
Floeter, Sergio R.
Total Authors: 9
 Univ Fed Santa Catarina, Dept Ecol & Zool, Florianopolis, SC - Brazil
 Univ Fed Mato Grosso do Sul, Ctr Ciencias Biol, Lab Ecol Movimento & Populacoes, Campo Grande, MS - Brazil
Total Affiliations: 6
Journal of the Marine Biological Association of the United Kingdom;
Web of Science Citations:
Resource partitioning is considered one of the main processes driving diversification in ecological communities because it allows coexistence among closely related and ecologically equivalent species. We combined three complementary approaches, i.e. the evaluation of foraging behaviour, diet composition and nutritional condition (RNA:DNA ratio), to assess feeding by two closely related (sister) butterflyfishes that are syntopic in Puerto Rico. Chaetodon capistratus had a higher abundance and higher bite rate and selected octocorals and hard corals for feeding, whereas Chaetodon striatus fed preferentially on sandy substrates. Cnidarians and polychaetes were the most representative diet items for both species, but C. capistratus preferred the former (Feeding Index of 74.3%) and C. striatus the latter (Feeding Index of 60.4%). Similar RNA:DNA ratios for both species suggest that, although they differ in feeding rates and diet, C. capistratus and C. striatus have similar nutritional fitness. Therefore, these species are both zoobenthivores but show clear differences in their substrate selection. The differences in the use of foraging substrate by C. capistratus and C. striatus, despite their close phylogenetic relationship and similar diets, suggest that these species coexist by resource partitioning. (AU)