Document ID: chunk:federal_register_of_legislation:F2019L00106:body:0:p9
Version: federal_register_of_legislation:F2019L00106
Segment Type: other
Provision Reference: 
Character Range: 24360–27109

253 mm (Lake 1959; 1978; Battaglene 1988; Harris & Rowland 1996; Douglas et al., 2002; Bruce et al., 2007; Knight & Bruce 2010; Lintermans & Ebner 2010).

Figure 1: Typical adult Macquarie perch from the Murray-Darling Basin
Photo – Luke Pearce, NSW Department of Primary Industries.
Figure 2: Typical adult Macquarie perch from the Hawkesbury-Nepean system
Note the substantially smaller adult size of the Hawkesbury/Nepean specimen (~17 cm) compared to the MDB specimen (~30 cm).
Photo – Andrew Bruce, NSW Department of Primary Industries

4 Biology and Ecology

    4.1 Age and growth

Growth rates of Macquarie perch vary between and within populations (Appleford et al., 1998; Tonkin et al., 2014; 2017b). Sizes of individuals vary greatly between the Murray-Darling Basin and Hawkesbury-Nepean populations, with the Basin individuals having greater potential maximum body sizes and weights (Harris & Rowland 1996). Murray-Darling Basin populations have been reported to grow from 7–10 mm (hatched larvae) to 370 mm in length in the first five years of life (Harris & Rowland 1996; Lintermans 2002; 2007; Kearns et al., 2012b). In east coast populations individuals greater than 190 mm in length are rare, with a maximum recorded size of 253 mm and 0.29 kg (Harris & Rowland 1996; Bruce et al., 2007; Knight & Bruce 2010).
Size at first sexual maturity varies between lake and river populations, with a study comparing fish from selected riverine tributaries in the Murray-Darling Basin and resident fish from Lake Dartmouth finding that both males and females of river populations tend to mature at a much smaller size, yet at the same age, than fish resident in the lake (Appleford et al., 1998). Still, size at a given age is likely to vary within Macquarie perch populations, especially once individuals are older than three years (Cadwallader 1984). Males are reported to mature at two years of age and at 210 mm and females at three years of age and 300 mm (Lake 1967a). However, it has become evident through later research that size is not a reliable indication of age because local conditions may induce the species to breed at smaller or larger sizes. Estimates of mature females as small as 100 mm total length have been made based on the length-at-age relationships formulated by Douglas et al. (2002). In the Cotter River in the Australian Capital Territory, males mature at about 140–150 mm and in Lake Dartmouth mature males have been recorded as small as 117 mm (Lintermans 2007).
The maximum age potential for Macquarie perch is at least 30 years (Tonkin/Vic DELWP unpub. data, cited in ARI pers. comm., 2017) and could potentially be older. The species is relatively long-lived, recent reports of fish from Victoria aged up