Species | Sillaginodes punctatus |
Common Name | King George Whiting |
Importance | |
Habitat | Sand, seagrass (juveniles < 100 mm long are found abundantly in patches of sand among shallow seagrass, while adults normally live and feed in bare sand habitat) |
Depth | 0 – 25 m (Edgar, 2008) |
Distribution | Jurien Bay, Western Australia, to northern New South Wales and northern Tasmania (Edgar, 2008) |
Diet | Amphipods and other crustaceans, polychaetes, molluscs, and peanut worms (Sipuncula) (Robertson, 1977) |
Stock Structure | Two genetically distinct populations in northern Tasmania (east coast St. Helens and northwest Stanley); Tas stock/populations are genetically distinct from mainland; two distinct mainland populations (combined SA and Vic, and WA); NW Tas stock (exposed coast) comprises sub-adults and adults, east coast Tas stock (protected estuary) dominated by juveniles. |
Movement | Movement offshore for spawning (Jenkins et al., 2016; Nicholls, 2018) |
M (Natural Mortality) | 0.16 (Tas populations combined) (Nicholls, 2018) |
Maximum Age (Years) | 15 (Kailola et al., 1993) |
Maximum Length (cm; assumed total length if no indication otherwise) | 690 (Edgar, 2008) |
Maximum Weight (g) | 5000 (Edgar, 2008) |
Female K (von Bertalanffy growth parameter) | 0.2 |
Male K (von Bertalanffy growth parameter) | 0.24 |
Female t0 (age (years) when length = 0) | -1.58 |
Male t0 (age (years) when length = 0) | -1.45 |
Female Loo (asymptotic von Bertalanffy length (cm)) | 57 (total length) (Nicholls, 2018) |
Male Loo (asymptotic von Bertalanffy length (cm)) | 51.9 (total length) (Nicholls, 2018) |
Size at Maturity (cm) | 40 (Jenkins et al., 2016; Nicholls, 2018) |
Age at Maturity (Years) | 4 (Jenkins et al., 2016; Nicholls, 2018) |
Spawning Season | Late summer – winter (March – late May) |
Spawning Location | Offshore – location unknown for Tasmanian stocks (Kailola et al., 1993; Fowler et al., 1999; Jenkins et al., 2016; Nicholls, 2018) |
Batch Fecundity (F) to Fork Length | BF = 461.16(TL)-143772.8 (BF = batch fecundity, TL = total length (mm); 29 samples from King Island) (Fowler et al., 1999) |
Batch Fecundity (F) to Age (A; years) | BF =3731.1(Age)-24202.65 (BF = batch fecundity; Age (years) 29 samples from King Island) (Fowler et al., 1999) |
Batch Fecundity to Weight (g) | BF = 129.07(W)-10254.66 (BF = batch fecundity, W = ovary-free weight (g); 29 samples from King Island) (Fowler et al., 1999) |
Egg Size | 0.72 – 1.055 mm diameter (Fowler et al., 1999) |
Recruitment | Variable, linked to environmental condisions resulting in strong and weak recruitment events that have major impacts on demographic structure of stock (Nicholls, 2018) |
Early Life History | Post-larvae (3-4 months old; approx. 2cm length) settle into shallow seagrass (Zostera and Posidonia) beds within bays and gulfs in winter/spring; juveniles inhabit sheltered shallow waters (<1.5 m) before migrating to deeper water (5 – 15m) at approx. 1.5 years of age and 250 mm TL (Jenkins, 2005; Jenkins et al., 2016) |