Blue Warehou Biology


SpeciesSeriolella brama
Common NameBlue Warehou
HabitatInshore reefs/harbours and open water
Depthā‰¤ 400 m (Edgar, 2008; Tilzey, 1994)
DistributionNew South Wales to South Australia, Tasmania, New Zealand (Edgar, 2008; Gomon et al., 2008)
DietInvertebrates: mainly salps; also krill, crabs, squid (Gavrilov and Markina, 1979; Annala, 1994; Bulman et al., 2001)
Stock StructureLikely two stocks in southern Australian waters (east and west of Bass Strait), although not genetically confirmed (Gavrilov and Markina, 1979; Robinson et al. 2008).
MovementSchooling fish, highly mobile; small juveniles pelagic, commonly in association with jellyfish in open coastal waters; sub-adults often found in sheltered waters of large marine embayments.
M (Natural Mortality)0.30 – 0.45 (Knuckey and Sivakumaran, 2001)
Maximum Age (years)15 (AFMA, 2014)
Maximum Length (total length; cm )90 (Gomon et al., 2008)
Maximum Weight (g)4000 (Gomon et al., 2008)
Unsexed K (von Bertalanffy growth parameter)0.37
Unsexed t0 (age (years) when length = 0)-0.67
Lāˆž (asymptotic von Bertalanffy length (total length; cm))
Length (TL; total length (cm)) ā€“ Weight (W; g) RelationshipW =0.03L^2.9 (Frimodt, 1995)
Size at Maturity (length (fork length; cm) at which 50% of population are sexually mature)36
Age at Maturity (age(years) at which 50% of population are sexually mature)3.67 (Knuckey and Sivakumaran, 2001)
Spawning SeasonWinter (major regional differences in magnitude and timing)
Spawning LocationCentral west and northwest coasts of Tasmania
Batch Fecundity (F; number of eggs) to Fork Length (FL; cm)ln(F)=2.614ln(FL)+2.366 (Knuckey and Sivakumaran, 2001)
Early Life HistoryLarvae restricted to shelf and slope waters; larvae likely to be transported by Zeehan Current from spawning grounds of western Tasmania to southeastern Tasmania nursery areas; larvae settle to bottom at length > 14.5 mm total length (Bruce et al., 2001b; Neira et al., 1998)
Gillnet Post Release SurvivalLow: 35% but small legal minimum length so rarely discarded (Lyle et al., 2014)