Abstract--Snoek (Thyrsites atun) is a valuable commercial species and an important predator of small pelagic fishes in the Benguela ecosystem. The South African population attains 50% sexual maturity at a fork length of ca.73.0 cm (3 years). Spawning occurs offshore during winter-spring, along the shelf break (150-400 m) of the western Agulhas Bank and the South African west coast. Prevailing currents transport eggs and larvae to a primary nursery ground north of Cape Columbine and ...
<1000 metric tons [t]/yr) off southern Australia, Chile, and Tristan de Chuna, and substantial fisheries (><500 g), or the nearest 10 g (fish><150 m), and line-caught snoek suggested that juveniles were also found in reasonable numbers to the east of Danger Point in regions 4 and 5. Thyrsites atun collected in demersal trawls deeper than 150 m were mostly><150 m), and line-caught snoek, nevertheless suggest a second nursery area to the east of Danger Point. But because handline catches in regions 4 and 5 amounted to only 10% of those in regions 1 and 2 (1985-97) and given that juvenile snoek made a substantially lower contribution to the diets of gannets foraging in this area, the area north of Cape Columbine is regarded as considerably more important to juvenile snoek. Thyrsites atun in demersal trawls made deeper than 150 m were mostly>
<150 m)
Summer-Autumn Winter-Spring
Fork length
(cm) M:F n [chi square] M:F n [chi square]
Regions 0-3
20-49 1:1 203 0.01 1:1.3 7 0
50-74 1:1.2 647 4.5 * 1:1.1 524 0.6><0.1
Emmelichthys nitidusr (D) 0 0 0
Spondyliosoma emarginatum (D) 0 0 0
Unidentified Teleostei 8.5 29.3 15.7><0.1
Zeus capensis (D)
Paracallionymus costatus (D) 1.5 1.6 0.2
Unidentified Teleostei 3.2 23.4 4.6
(1) Two species of hake occur in South African waters--M. paradoxus and
M. capensis--but owing to difficulty differentiating partially digested
specimens, they were not analyzed separately.
Table 5
Proportions (%) of stomachs with food, and the mean mass
of stomach contents for adult (>