Biology
| Species | Trachurus declivis |
| Common Name | Jack Mackerel |
| Importance | Minor |
| Habitat | Open Water |
| Depth | 0 – 500 m (Edgar, 2008) |
| Distribution | Western Australia (Shark Bay) to southern Queensland, around Tasmania, New Zealand (Edgar, 2008) |
| Diet | Krill, planktonic crustaceans, fish (Kailola et al., 1993) |
| Stock Structure | Most likely two subpopulations: eastern Australian (eastern Tasmania and eastern seaboard of mainland Australia), western Australian (western Tasmania, Great Australian Bight, Western Australia) (Kailola et al., 1993; Jorden et al., 1998; Bulman et al., 2008) |
| Movement | Schooling fish; normally inhabit in continental shelf waters, may move close to seabed during winter |
| M (Natural Mortality) | 0.63 – 0.70 (Stevens and Hausfeld, 1982) |
| Maximum Age (years) | 25 (Paul, 2000) |
| Maximum Length (total length; cm) | 64 (Paul, 2000) |
| Female K (von Bertalanffy growth parameter) | 0.267 |
| Male K (von Bertalanffy growth parameter) | 0.267 |
| Female t0 (age (years) when length = 0) | -1.21 |
| Male t0 (age (years) when length = 0) | -1.21 |
| Female L∞ (asymptotic von Bertalanffy length (total length; cm)) | 36.2 |
| Male L∞ (asymptotic von Bertalanffy length (total length; cm)) | 36.2 |
| Length (TL; total length (cm)) – Weight (W; g) Relationship | W=1.46.10^(-8) L^2.982 (males and females) (Lyle et al., 2000) |
| Spawning Season | Late December – early March |
| Spawning Location | Occurs over wide area in Tasmania (Stevens and Hausfeld, 1982) |
| Additional Spawning Information | Pelagic eggs |
| Recruitment | No-stock recruitment relationship established |
| Early Life History | Larvae carried by inshore currents; juveniles inhabit coastal and estuarine waters, although they may sometimes be found offshore (Kailola et al., 1993; Williams and Pullen, 1986) |
