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Fishery Bulletin 103(2) 



Apart from being indicators of spawning seasonality, 

 GSI trends can provide insight into the mating patterns 

 of a species (Sadovy, 1996). Pair-spawning sparids such 

 as Chrysoblephus laticeps have low male GSI (±10% of 

 female) during the spawning season (Buxton, 1990). 

 Although the spawning behavior of carpenter has not 

 been documented, the GSI of males (average 3.0 ±1.4) 

 was similar to that of females (average 3.3 ±1.4) dur- 

 ing the spawning season (Fig. 4). The large testes size 

 suggests that carpenter are group spawners and that 

 sperm competition is high (Sadovy, 1996). Further evi- 

 dence for group spawning is the lack of sexual dimor- 



phism in this species (Smale, 1988; Mann and Buxton, 

 1998; Griffiths et al., 2002). 



Like many other South African sparids, carpenter are 

 summer spawners (Buxton and Clarke, 1986; Buxton 

 and Clarke, 1991; Buxton, 1993). Although various en- 

 vironmental cues have been suggested for this seasonal 

 spawning, it is probably a combination of events that 

 leads to gonad maturation and spawning. Smale (1988) 

 and Garratt (1985) speculated that increases in gonad 

 activity of Petrus rupestris and Chrysoblephus puniceus 

 were attributed to an increase in photoperiod and water 

 temperature respectively; Scott and Pankhurst (1992), 



