habitat_narrative
Marine
Sarpa salpa is a herbivorous grazer of algae species and inhabits areas with rocky or sandy bottoms covered with seaweeds, to depths of about 70 m. This species is gregarious, sometimes forming sizeable schools. In southern Africa, adults inhabit subtidal gullies and shallow rocky reefs and are largely confined to the surf zone. Juveniles are found in tidal rockpools, sandy littoral, shallow reefs and estuaries in the Southeastern Cape and Southwestern Cape (Mann and Dunlop 2013). There is evidence of an adult migration in South Africa with adults migrating from juvenile nursery areas in the Western and Eastern Cape to breed in the warmer waters of KwaZulu-Natal (van der Walt and Mann 1998). They remain in the inshore zone (<15m) and there is little evidence of a return migration to the Cape although some of the largest specimens have been caught in Cape waters (Mann et al. 2000). Sarpa salpa is mainly herbivorous, but sometimes also feed on small crustaceans (Carpenter, in press). Some individuals are toxic after ingestion of the alga Caulerpa (Fischer et al. 1987). The maximum length of this species is 51 cm (Fischer et al. 1987), but seldom exceeds 30 cm in South African waters. The maximum age recorded for this species in South African waters is six years and the maximum weight is 0.7 kg, a South Africa angling record (Mann and Dunlop 2013), whereas this species has been aged up to 11 years with a maximum weight of 1.5 kg in the Canary Islands (Villamil et al. 2002).Growth
Growth of this species is described in the following equation Lt = 224 mm FL(1-e-0,55/yr(t+0.51yrs)) in Kwazulu-Natal (van der Walt and Beckley 1997). The allometric coefficient of the length-weight relationship is 3.04 (Criscoli et al. 2006). In the Canary Islands, the parameters of the von Bertalanffy growth equation for all individuals were: Linf = 479 mm, k = 0.212 year-1 and t0 = -1.08 year-1 (Villamil et al. 2002).
Reproduction
Sarpa salpa is characterized by protandric hermaphroditism (van der Walt and Mann 1998, Villamil et al. 2002) but was previously described as a rudimentary hermaphrodite (Joubert 1981). Sex change normally occurs between 18 and 22 cm fork length, corresponding to and age of around three years (van der Walt and Mann 1998). The size at maturity is 14.5 cm, at which most individuals are males although some primary females may also be present (i.e. dygynous). In Cape Verde, two distinct spawning periods are observed: one in spring, from March to May, and the other in autumn, from the end of September to November. In Kwazulu-Natal, spawning occurs in winter and spring from April to September with a peak from June to August (van der Walt and Mann 1998). Spawning takes place over shallow subtidal reefs along the KwaZulu-Natal coast (Joubert 1981, van der Walt and Mann 1998, Connell 2012), while some spawning has also been recorded off the Eastern Cape coast (Heemstra and Heemstra 2004). The age at 50% maturity for this species in KwaZulu-Natal is about 1.5 years (van der Walt and Mann 1998). The length at 50% maturity for males is 14–15 cm FL, 16–17 cm FL and for females (Joubert 1981) and 14.5 cm FL for combined sexes (van der Walt and Mann 1998).
In the Canarian archipelago, the overall sex ratio was unbalanced in favour of males (1:0.41). The reproductive season extends from September to March, with a peak in spawning activity in winter (December-January). Males reached maturity at a smaller length (226 mm, two years old) than females (294 mm, three years old). Individuals aged zero to 11 years were found (Villamil et al. 2002).
