Logo image
Inter- and intraspecific partitioning of food resources by six large and abundant fish species in a seasonally open estuary
Journal article   Peer reviewed

Inter- and intraspecific partitioning of food resources by six large and abundant fish species in a seasonally open estuary

M.E. Platell, P.A. Orr and I.C. Potter
Journal of Fish Biology, Vol.69(1), pp.243-262
2006
url
Link to Published Version *Subscription may be requiredView

Abstract

This study has tested the hypotheses that the dietary compositions of the six large and abundant fish species in the 46 km2 basin of a seasonally open estuary (Wilson Inlet) will differ significantly, change with increasing body size and vary with water depth and season. These species comprise four marine species, the sea mullet Mugil cephalus, yellow-eye mullet Aldrichetta forsteri, King George whiting Sillaginodes punctata and Australian herring Arripis georgiana, and populations of two species that are confined to the estuary, the cobbler Cnidoglanis macrocephalus and the southern blue-spotted flathead Platycephalus speculator. Non-metric multidimensional ordination and associated tests showed that, overall, the dietary composition was influenced to a far greater extent by the species of fish than by either water depth or season. At even a relatively broad level of taxonomic discrimination, the dietary compositions of each pair of species were significantly different, except for those of A. georgiana v. P. speculator, and even in that case those of their larger individuals differed. Differences among the diets of the six species, which represented five families, are related to differences in feeding morphology and location within the water column. Mugil cephalus ingested almost exclusively sediment and fine organic material. Although A. forsteri and S. punctata both consumed substantial amounts of polychaetes (including nereids, capitellids and orbiniids), the former ingested relatively larger volumes of small crustaceans (copepods) and relatively lower volumes of large crustaceans (the carid Palaemonetes australis), nemertines and bivalve siphons. The diets of A. georgiana and P. speculator were both typified by the consistent and high contributions of large crustaceans and fishes. Among fish prey, however, A. georgiana focused to a far greater extent on the small clupeid Engraulis australis, whereas P. speculator consumed a wider range of teleosts, which included species of atherinid and goby. Although the diets of A. forsteri and C. macrocephalus both contained substantial amounts of coarse organic material, the latter differed markedly from those of all other species by the frequent presence of mytilids (mainly Xenostrobus spp.) and other bivalves (especially Tellina deltoidalis and Irus crenata). The diets of each species except M. cephalus changed with increasing body size and, for comparable size classes, did not differ between shallow and deeper waters. The partitioning of food resources within and among the six large and abundant fish species found in Wilson Inlet would reduce the potential for competition for these resources and help account for the large numbers of those species in this seasonally open estuary.

Details

UN Sustainable Development Goals (SDGs)

This output has contributed to the advancement of the following goals:

#13 Climate Action
#14 Life Below Water

Source: InCites

Metrics

InCites Highlights

These are selected metrics from InCites Benchmarking & Analytics tool, related to this output

Collaboration types
Domestic collaboration
International collaboration
Citation topics
3 Agriculture, Environment & Ecology
3.2 Marine Biology
3.2.1182 Coastal Vegetation
Web Of Science research areas
Fisheries
Marine & Freshwater Biology
ESI research areas
Plant & Animal Science
Logo image