Life history and habitat preference in the Darling hardyhead, Craterocephalus amniculus (Teleostei, Atherinidae) in the northern Murray‐Darling Basin, Australia

Abstract

The Darling hardyhead, Craterocephalus amniculus (Atherinidae), is a threatened fish species inhabiting upstream reaches of a number of northern Murray-Darling Basin catchments. Little is known of its life history. Our goal was to determine patterns of seasonal size structure, interannual and spatial variation in diet, and habitat selection in this species across multiple sites and years in the upper Macintyre River, northern New South Wales. Preserved specimens from a separate study were used to obtain information on diet and size structure. Size structures suggested a single annual spawning season in late September or early October. Diets varied significantly, both between years at the downstream site and among the three sites although the underlying cause of this was untested. Dietary diversity increased with distance downstream. At the two upstream sites, aquatic invertebrates made up most of the diet while over half the gut contents at the downstream site was unidentified detritus. Preference was shown for pool habitats with a sand or cobble substrate, increased channel depth and width and distance from the bank, and reduced flow velocity. Overhanging exotic riparian vegetation and instream woody debris were non-preferred. This species may be vulnerable to further population decline in light of its restricted habitat preferences and narrow spawning season. However, comparable data from nearby catchments will be necessary to ascertain the species' conservation status across its broader distribution.

Unravelling the taxonomy and identification of a problematic group of benthic fishes from tropical rivers (Gobiidae: Glossogobius)

“…Just because species are visually similar in appearance does not necessarily mean they have similar ecology (Hammer et al, 2013;Moy et al, 2018;Raadik, 2014), especially given the larger genetic divergence noted between Glossogobius species here. The newly developed systematic framework suggests that most historic biological studies will be (a) assigned to the wrong taxa (e.g., despite large numbers of historical records, both forms of G. giuris appear absent from the Gulf of Carpentaria, at least from more frequently sampled areas above the estuarine interface) and (b) confounded by the unrealised presence of two or more species, with up to four species recorded in regional and site-based sympatry in the Daly River as the extreme example.…”

Characterization of the karyotype and accumulation of repetitive sequences in Australian Darling hardyhead Craterocephalus amniculus (Atheriniformes, Teleostei)

“…The Darling hardyhead, C. amniculus is a small bodied species with an annual lifecycle and a habitat preference for deep slow flowing pools (Moy, Wilson & Ellison, 2018). This species is naturally distributed throughout the upper tributaries of the Darling River of the Murray-Darling Basin and the coastal Hunter River (Adams et al, 2011).…”

Characterization of the karyotype and accumulation of repetitive sequences in Australian Darling hardyhead Craterocephalus amniculus (Atheriniformes, Teleostei)

“…The Darling hardyhead, C. amniculus is a small bodied species with an annual lifecycle and a habitat preference for deep slow flowing pools (Moy, Wilson & Ellison, 2018).…”