habitat_narrative
Marine
Diplodus capensis primarily occurs in the surf-zone in close association with rocky habitats (Joubert 1981, Wallace et al. 1984, Beckley and Buxton 1989, Mann 1992). Adults of this species inhabit shallow rocky and sandy substrata down to 40 m while juveniles are found in shallow subtidal reefs, subtidal gullies, intertidal pools, sandy beach surf zone, and estuary mouths (Christensen 1978; Joubert 1981; Lasiak 1981, 1984; Beckly 1983, 1985; Berry et al. 1982; Bennett 1987, 1989; Smale and Buxton 1989; Mann 1992; Mann and Attwood 2000; Watt-Pringle 2009; Mann and Dunlop 2012). Eggs and larvae are pelagic and distributed inshore of the Agulhas Current throughout the distributional range (Brownell 1979, Connell 2012). Tagging studies suggest that D. capensis adults are highly resident and juveniles also demonstrate high levels of site fidelity in rocky intertidal nursery areas (Bennett and Attwood 1991, Attwood and Bennett 1995, Watt-Pringle 2009). Adults of this species feed on a wide variety of prey including red and green algae, echinoids, polychaetes, anthozoans, gastropods, bivalves and ascideans (Joubert and Hanekom 1980, Coetzee 1986, Mann and Buxton 1992). Juveniles feed primarily on small crustaceans, copepods, polychaetes and echinoids (Mann and Buxton 1992).Reproduction
Diplodus capensis from South Africa exhibits digynous hermaphroditism with partial protandry occurring in some of the male population (Coetzee 1986, Mann and Buxton 1998). This species reaches maturity from 15 to 16 cm FL in KwaZulu-Natal (Joubert 1981) and 21 cm FL in the Eastern Cape at an age of three years (Mann and Buxton 1998). Male:Female sex ratios were biased in favour of males (1.3:1) in an exploited population in KwaZulu-Natal (Joubert 1981), but females were dominant in a protected population in the Tsitsikamma National Park (1:1.98) (Mann and Buxton 1998). Length and age at sex change is variable for this species as it is not genetically predetermined (Mann and Buxton 1998, Mann and Attwood 2000, Baroiller et al. 1999, Avise and Mank 2009). The maximum length recorded for D. capensis is 45 cm TL and 2.7 kg weight (Smith and Smith 1986, South African Shore Anglers Association 2012). The maximum recorded age for this species is 21 years (female) (Mann and Buxton 1998).
The spawning season takes place from May to December, peaking from June to September in KwaZulu-Natal (Joubert 1981, Connell 2012), and in the Eastern Cape D. capensis spawns from August to March, with peak spawning between September and December (Coetzee 1986, Mann and Buxton 1998). Spawning occurs on inshore reefs, within 30 m depth, probably throughout its distribution (B. Mann pers. obs., Connell 2012). Diplodus capensis is a group-spawning species as males and females aggregate into a group of eight to fifteen individuals, swim vigorously in a ball near the surface in shallow water, and release sperm and eggs simultaneously into the water column (Richardson et al. 2011).
Generation length for D. capensisis is estimated to be six years, using the following equation for a gonochoristic fish species: Generation length = Σxlxmx/Σlxmx (Provided by Prof. Colin Attwood, University of Cape Town).
