Griffiths: Life history and stock separation of silver kob, Argyrosomus inodorus 
53 
(during similar months and times of dayXFig. 11). 
Very low numbers of females with hydrated oocytes 
have also been reported in line catches of other 
sciaenids, e.g. Sciaenops ocellatus (Fitzhugh et ah, 
1988), Micropogonias undulatus (Barbieri et al., 
1994), and Atractoscion aequidens (Griffiths and 
Hecht, 1995a); no hydrated oocytes were detected 
from line catches of Argyrosomus japonicus (Griffiths, 
in press, b). Most silver kob caught during SCBS’s 
were juveniles. Nevertheless, none of the adult fe- 
males that were trawled had hydrated oocytes, per- 
haps because these fish were captured on the nurs- 
ery grounds and not on adult habitat where spawn- 
ing is expected to occur (see below). 
The large proportion of ripe and ripe and running 
(stages 5 and 6) males and females at each of the 
five sites between Cape Point and the Kei River ( Fig. 
11) during October-November suggests that spawn- 
ing occurs throughout the study area and that peak 
spawning occurs during spring for all three stocks. 
The inshore distribution of the adults during spring 
and summer, the absence of Argyrosomus eggs and 
larvae in the Agulhas Current (ca. 200 mXBeckley, 
1993), and the occurrence of significant numbers of 
early stages of A. inodorus larvae (identified as “A. holo- 
lepidotus “) in 5-7 m in Algoa Bay (Beckley, 1986) sug- 
gest that spawning occurs in less than 50 m depth of 
water. However, even though early life stages of lar- 
vae and juvenile recruits (see “nursery areas” below) 
are found just seaward of the surf zone (5-7 m), it is 
not certain whether spawning occurs in this area or 
whether it occurs in slightly deeper water and the eggs 
and larvae are transported shorewards by currents. 
Although spawning in other sciaenids, including 
A. japonicus, occurs at night (Fish and Cummings, 
1972; Takemura et al., 1978; Holt et al., 1985; Saucier 
and Baltz, 1993; Connaughton and Taylor, 1995; 
Griffiths, in press, b), the fact that large proportions 
of ripe and running females caught in seine nets in 
False Bay (Fig. 11) were caught between 11:30 h and 
14:30 h, suggests that spawning in A. inodorus may 
occur during the day. The water temperature in which 
ripe and running females were captured was 18- 
19°C, but as indicated for other sciaenids (Saucier 
