Scalefish Bluethroat Wrasse Biology


SpeciesNotolabrus tetricus
Common NameBluethroat Wrasse
HabitatSheltered and exposed reefs
Depth1 – 160 m (Edgar, 2008)
DistributionSydney (New South Wales) to Ceduna (South Australia) (Edgar, 2008)
DietMolluscs and crustaceans (Shepherd and Clarkson, 2001)
Stock StructureNo information available
MovementSite-attached, with females showing overlapping home ranges and males territorial, at least during the reproductive season. No apparent migration of individuals between reefs (Barrett, 1995b)
M (Natural Mortality)0.2 (low adult mortality for both species, estimated for N. tetricus) (Barrett, 1995b; Smith et al., 2003)
Maximum Age (years)11 (Barrett, 1995b)
Unsexed K (von Bertalanffy growth parameter)0.2
Unsexed t0 (age (years) when length = 0)-0.35
Unsexed L∞ (asymptotic von Bertalanffy length (fork length; cm))36.12
Length (FL; fork length (cm)) – Weight (W; g) RelationshipW=0.0545L^2.7157 (Barrett, 1995b; Welsford, 2003)
Size at Maturity (length (fork length; cm) at which 50% of population are sexually mature)29.89 (females before sex change)
Age at Maturity (age (years) at which 50% of population are sexually mature)8 (females before sex change) (Barrett, 1995a; Harwood, and Lokman, 2006)
Sexual developmentProtogynous hermaphrodite (not all individuals undergo a sex inversion); sex change occurring between 27 – 32 cm in Tasmania
Spawning SeasonAugust – January (Barrett, 1995b)
Early Life HistoryPlanktonic larval duration ranges from 44 – 66 days; settlement on reefs at around 10.4 mm (Welsford, 2003)