Premium
Critical Thermal Minima of age‐0 Australian bass, Macquaria novemaculeata , fingerlings: implications for stocking programmes
Author(s) -
CAMERON L. M.,
BAUMGARTNER L. J.,
BUCHER D. J.,
ROBINSON W.
Publication year - 2012
Publication title -
fisheries management and ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.693
H-Index - 55
eISSN - 1365-2400
pISSN - 0969-997X
DOI - 10.1111/j.1365-2400.2012.00850.x
Subject(s) - stocking , fishery , bass (fish) , acclimatization , biology , critical thermal maximum , zoology , fish <actinopterygii> , ecology
Fishes are often stocked outside natural distribution ranges with inadequate information on target streams, particularly thermal regimes. Australian bass , Macquaria novemaculeata (Steindachner), is a catadromous species that is regularly stocked into upland reaches of rivers and impoundments in south‐eastern Australia. Critical Thermal Minima (CTMin) were determined for age‐0 Australian bass fingerlings with a mean fork length of 64.4 ± 0.4 mm and weighing 3.8 ± 0.8 g. Four treatments were used, including three replicate aquaria for each treatment. Fingerlings were acclimated at either 8 or 15 °C at densities of 15 fish in 56‐L glass aquaria. Water temperatures were then decreased at either 1 °C day −1 or 1 °C h −1 until loss of equilibrium (LOE), which occurred between 3 and 7 °C. Mean CTMin among treatments was 3.22–4.64 °C and was influenced by acclimation temperature and rate of temperature decline. Fingerlings acclimated at 8 °C subjected to a temperature decline of 1 °C h −1 experienced highest LOE temperature. Post‐LOE mortality among treatments was highest at 100% in the 8 °C acclimation with a 1 °C day −1 temperature decline. Mortalities following LOE occurred within 5 days. The results suggest that stocking age‐0 Australian bass is unlikely to be successful in areas where winter temperatures fall below 6 °C.