Yellowfin whiting inhabit relatively shallow waters for their entire life, often found on tidal flats and creeks, as well as large estuaries.
Yellowfin whiting are benthic carnivores, preying predominantly on polychaete worms, with minor amounts of copepods, amphipods and bivalves also commonly taken.
[3] The species was first recognised and scientifically described by the German naturalist Wilhelm Peters in 1864 based on the holotype collected from the waters near Adelaide, the capital city of South Australia.
[4] Peters assigned the species name schomburgkii in honor of the German explorer and botanist Moritz Richard Schomburgk, who became the second Director of the Adelaide Botanic Gardens.
[4] The yellowfin whiting has a similar body profile to most other Australian sillaginids, with colour and swimbladder morphology the simplest identifying features.
It is one of the largest members of the Sillaginidae, growing to a known maximum known length of 42 cm and a weight of 860 g.[6] The body is elongate and compressed, with the dorsal profile more arched than the ventral.
The body is covered in small ctenoid scales extending to the upper head and nostrils of the fish, also present behind each ray of the dorsal and anal fins.
The swimbladder has an incised anterior margin with no median or anterolateral projections and there is a single tapering posterior extension which rapidly narrows to a slender tube.
[10] Yellowfin whiting primarily inhabit shallow protected inshore waters in depths of less than 10 m, often moving across tidal flats less than a meter deep.
[11] The dietary and reproductive biology of the yellowfin whiting has been extensively studied in Western and South Australia, where it comprises a major part of the fishery.
[2] The yellowfin whiting is a benthic predator, using its well developed eyesight and a downward pointing jaws that can be protruded to 'suck up' and capture its prey from the seafloor.
[13] Studies conducted in southwest Western Australia found the species predominantly takes polychaetes as its main prey item, although crustaceans, particularly amphipods and penaeids also make up a large portion of its diet.
Items taken infrequently or in lesser amounts include small teleost fish, bivalve molluscs, marine plant material and other crustaceans such as tanaids, decapods and cumaceans.
[12][13] Modeling with the stable isotopes 13C and 15N indicate that seagrass and epiphytic algae were the primary initial sources of energy and nutrition that flow into the fish via detritivores which the species preys on, with salt marsh plants and macroalgae contributing in some settings.
[12] The yellowfin whitings' diet also varies spatially and temporally, which appears to be a function of prey availability at different sites and periods of the year.
[12] There is little resource partitioning between the small individuals of sillaginids which inhabit shallow inshore habitats, with Sillago vittata, S. burrus and Sillaginodes punctatus also taking copepods as their primary prey in southwest Western Australia.
By the time they reach 2.7 mm, the mouth and gut are functional, the eyes are pigmented, a gas bladder is present, and yolk absorption is complete.
Yellowfin whiting are actually most commonly targeted from beaches, estuaries and jetties constructed over shallow waters, with good catches often made on the ingoing and outgoing period of the tide.
[23] Specialist whiting fishermen often attach a red bead or piece of tubing directly above the hook to attract the fish, although the usefulness of this is debated.
[10] A similar survey conducted in the South Australian Gulfs found recreational fishermen accounted for 28% of the entire yellowfin whiting taken during the 2000/2001 period, representing over 50 tonnes of fish.