To clarify the feeding habits of seagrass fishes,
we examined the gut contents from 42 fish species collected
in seagrass habitats in Trang. Thirteen species
showed ontogenetic and/or seasonal changes in food-use
patterns. Smaller individuals generally preyed on small
planktonic items (e.g., copepod larvae) or small benthic/
epiphytic crustaceans (e.g., harpacticoid copepods), with
subsequent changes to other prey items (e.g., shrimps,
crabs, detritus and filamentous algae) with growth. The
most important dietary items for the seagrass fish
assemblages comprised benthic/epiphytic crustaceans,
detritus, and planktonic copepods. Cluster analysis based
on dietary overlaps showed that the seagrass fishes comprised
eight feeding guilds (large benthic/epiphytic crustacean,
detritus, planktonic animal, small benthic/epiphytic
crustacean, mollusc, invertebrate egg, polychaete, and fish
feeders). Of these, the first three guilds were the most
abundantly represented, whereas the last three were each
represented by only a single species.