Glimpse into guts: overview of the feeding of larvae of tropical shorefishes

Knowledge of the diets of tropical fish larvae is limited to only a few taxa. Here, we describe the diets of 591 individuals from 50 families of tropical larval shorefishes collected off the Northwest Shelf of Australia (21° 49′ S, 114° 14′ E), effectively doubling the number of families for which there is dietary data available. The diversity of prey items eaten differed significantly among families. The majority of fish larvae ate copepods but there were some interesting exceptions. Chaetodontids ate only chaetognaths, acanthurids and nemipterids ate appendicularians, and tetraodontids ate predominately non-copepod prey (44% decapod larvae, 20% bivalves and 15% protists). Within the fish families that specialised on copepod prey there were marked differences in the types of copepod prey, with a clear preference shown for calanoid copepods, particularly small calanoids such asBestiolina similisandTemoraspp. Copepod communities in the area are food-limited and we suggest that the ability of some larval fishes to feed on components of the microbial food web may be an important determinant of their success.