A historical and contemporary consideration of the diet of the reef manta ray (Manta alfredi) from the Great Barrier Reef, Australia

The preserved stomach contents from the manta ray, collected in 1935, that provided the basis for the 2009 taxonomic resurrection of the species Manta alfredi, were examined. The majority of the material comprised calanoid copepods (61.7%) and trypanorhynch cestodes (34.6%), with minor contributions by arrow worms, a barnacle larva and a nematode. Comparison of the size-frequency distributions of stomach contents with that of zooplankton from the Great Barrier Reef region suggest that this manta ray preferentially ingested large copepods, or that the filter mechanism used to extract prey from the water was selective for prey items over 0.8mm in length. This is the first description of the diet of M. alfredi from stomach contents, and is consistent with previous inferences about what this species consumes.