Importance of benthos in the trophic structure of the ichthyofauna of los frailes reef, gulf of California, Mexico

The Gulf of California comprises a great diversity of benthic ecosystems. The western coast in particular is dominated by rocky and coral reefs that shelter a wide diversity and abundance of species. Despite the importance of benthic ecosystems for the structure and organization of associated communities, few studies have focused on the importance of benthos in the trophic organization of the fish community. In this chapter the fish communities of four areas of the Los Frailes rocky reef differing in benthic structural complexity (BSC) were evaluated through visual censuses. According to the BSC two low benthic structural complexity (LBSC) areas and two high complexity (HBSC) areas were identified. The HBSC areas had a higher number of cavities, greater depth and greater substrate heterogeneity. However, despite differences in structural complexity, the trophic organization of the ichthyofauna did not show significant changes in terms of formation of functional trophic groups (FTG) between the HBSC (21 FTG) and LBSC (19 FTG) locations. The biomass flow diagram of the different prey species of carnivorous, omnivorous and herbivorous fish present in the reef showed variable connections and biomass flow, with dominance of benthic prey species, which highlights the importance of benthic invertebrates as a source of energy for the reef ichthyofauna.