A long-lived, estuarine-resident fish species selects its macroinvertebrate food source based on certain prey and predator traits

• Published in: Estuarine, coastal and shelf science coastal and shelf science, 2022-01, Vol.264, p.107691, Article 107691
• Main Authors: Potter, Ian C., Kanandjembo, Angie-Riitta, Cottingham, Alan, Rose, Thomas H., Linke, Thea E., Platell, Margaret E.
• Format: Article
• Language: English
• Subjects: Crustaceans; Epifaunal benthic macroinvertebrates; Infaunal benthic macroinvertebrates; Molluscs; Polychaetes; Species prey size category
• ISSN: 0272-7714; 1096-0015
• DOI: 10.1016/j.ecss.2021.107691

This study has explored the extent to which the predominant faunal component of the diet (benthic macroinvertebrates) of the large, long-lived estuarine-resident Acanthopagrus butcheri is related to particular prey and predator traits. Focus is placed on the location (infaunal vs epifaunal) and species size category (small vs medium vs large) of the prey and feeding behaviour of A. butcheri. Data on the benthic macroinvertebrates in the stomach contents of A. butcheri in a microtidal estuary (Swan-Canning, Western Australia) are compared with those of macroinvertebrates sampled in the benthos at the same sites and times in eight consecutive seasons using an Ekman grab. The eight most abundant small macroinvertebrate species in the benthic samples were infaunal and, apart from the bivalve Arthritica semen that was ingested by only a few fish, were not fed on by A. butcheri. In contrast, the three most abundant medium and large-sized species in the benthos, the epifaunal bivalves Xenostrobus securis and Fluviolanatus subtortus and infaunal nereidid polychaete Simplisetia aequisetis, were preyed on substantially, with the first ingested by 54% of A. butcheri and contributing over 51% to dietary volume. Although the eunicid polychaete Marphysa sanguinea occurred in only 7% of benthic samples and contributed