Differences of Macroalgal Consumption by Eight Herbivorous Coral Reef Fishes From the Xisha Islands, China

Herbivorous fishes play an important role in preventing the overabundance of macroalgae on coral reefs. Understanding feeding selectivity and consumption by herbivorous can be challenging studies their ecological preservation recovery Coral reef decline, macroalgal overgrowth overfishing are clearly visible Xisha Islands, China. However, there seldom behaviors this area. We used microscopy, 18S rRNA high-throughput sequencing, stable isotope analyses to comprehensively examine diet eight fish species common including one parrotfish, two chub, unicorn fish, three rabbitfish. Based microscopic examination, Siganus argenteus fed highest number (five species), followed Naso unicornis (four species). Kyphosus cinerascens , K. vaigiensis N. S. punctatissimus entire thallus, indicating greater importance compared with that only consume algal fronds. According sequencing intestinal contents, cluster analysis revealed consumed composition from always grouped together based species, but low similarity. removed diversity as well greatest quantity macroalgae. Calotomus carolinus red alga Pneophyllum conicum which is widely distributed Indo-Pacific reefs overgrow kill live corals. was found occupy lowest trophic position analysis. Multi-technique showed a high potential macroalgae, suggesting they key browsers should receive priority protection Islands. A diverse fauna also very These results not demonstrated various functions different removal, provided insights into management South China Sea.