Dietary niche differentiation of five sympatric species of Platycephalidae

Abstract

The dietary composition and partitioning of food resources between five sympatric species of Platycephalidae inhabiting the coastal waters of New South Wales, Australia was investigated. Samples were collected monthly between March and November 2007 onboard commercial ocean prawn trawlers based in the ports of Yamba and Newcastle. Monthly percentage weight contribution of 12 prey categories was analysed to determine if diet was influenced by the variables: species, location, depth, size and maturity. Of the 959 stomachs from the five species examined, 28-54% contained prey. All Platycephalid species primarily consumed teleosts, however the diversity of prey and the proportion each prey type contributed to the overall diet varied substantially between species. Platycephalus caeruleopunctatus, P. longispinis, P. richardsoni and Ambiserrula jugosa were generalist carnivores and consumed prey from a wide variety of phyla including teleosts, crustaceans, polychaetes, molluscs and echinoderms. In contrast, Ratabulus diversidens were primarily piscivorous.Partitioning of prey resources between species was more evident in waters at Yamba than at Newcastle. Differences in diet between locations were considered a result of differential prey exploitation rather than shifts in the suite of prey consumed. Dietary composition was observed to be influenced by size, maturity status and depth however these differences were not observed for all species.

Effects of Reef Proximity on the Structure of Fish Assemblages of Unconsolidated Substrata

“…4), which is consistent with other studies in this marine park [17], [25]. Snapper, P. auratus , was mostly associated with reef, with highest abundance at 25 and 50 m, but also contributed to the halo assemblage at 100 and 200 m (Fig.…”

Depth interactions and reproductive ecology of sympatric Sillaginidae: Sillago robusta and S. flindersi

“…In the present study, the shallow-water preference of small S. flindersi placed them directly in the preferred habitat of S. robusta. It is conceivable that a dietary mechanism ensured the smaller S. flindersi individuals were not competitively disadvantaged , Barnes et al 2011. Alternatively, necessary resources in the shallow strata may not have been limited, reducing the need for species stratification.…”

Acanthocephalan Cystacanths from Flatfish (Order Pleuronectiformes) in Tropical Australian Waters

“…Similarities in the ecology of flathead and the species of flatfish infected in this study may promote infection with larvae of S. sagittifer. Notes taken on the dietary items of the flatfish in this study showed a dominance of crustaceans (shrimp and crab claws predominately); flathead are also known to forage on crustaceans(Barnes et al, 2011) and crustaceans are presumed intermediate hosts of various acanthocephalans(Kennedy, 2012).Abdel-Ghaffar et al (2014) found prevalence of infection varied between seasons, with more fish infected, leading to higher prevalence of infection in definitive hosts, over summer months.Previously known from southern Australian waters (and other temperate locations), these are the first records of C. cetaceum from the eastern Queensland coast, albeit from paratenic hosts. The definitive hosts of C. cetaceum include the short-beaked common dolphin, Delphinus delphis (Linnaeus), and the common bottlenose dolphin,…”