habitat_narrative
Marine
Chrysoblephus gibbiceps is a reef associated, sedentary species that may occur in large shoals and is common on reefs below 20 m (Buxton and Smale 1984, van Zyl 2013, Griffiths and Wilke 2002, Smale and Buxton 1989, Beckley and Buxton 1989, Lechantuer and Griffiths 2002). This species is found to depths of 150 m (van der Elst 1988, 1993). Chrysoblephus gibbiceps is an extremely resident species with adults inhabiting offshore reefs while juveniles occur over shallow hardbottom reefs (Wilke and Griffiths 1999, Buxton and Smale 1984). Lechantuer and Griffiths (2002) note its seasonal occurrence in False Bay and its increased abundance at water temperatures >13°C and increased depth.Chrysoblephus gibbiceps is a benthic carnivore that feeds on a wide variety of reef associated invertebrates including crustaceans, molluscs and echinoderms (van der Elst 1993, Wilke and van Zyl 2012). Adults of this species feed primarily on ophiuroids, gastropods, and polycheate worms although their diet also includes sea urchins, octopus, and crabs (Heemstra and Heemstra 2004). The diet of juvenile C. gibbiceps <30 cm consists of soft bodied organisms such as malacostraca and as juveniles increase in size, they feed more on hard prey including gastropods (van Zyl 2013).
Reproduction
Chrysoblephus gibbiceps is a late gonochorist (sensu rudimentary hermaphrodite) and lays small pelagic eggs (Buxton 1985, van Zyl 2013). The spawning season in the Southeast Cape is from October to January and peaks in December on the central Agulhas Bank (C.D. Buxton DIFS unpublished data, Wilke and van Zyl 2012). Ripe individuals have been reported from the Southeast Cape and on the Agulhas Bank (van Zyl 2013).
The length at 50% maturity for this species is 21.2 cm FL for males and 24.9 cm FL for females while most individuals over 35 cm are mature (Wilke and van Zyl 2012, van der Elst 1993). The age at 50% maturity is 2.2 years for males and 3.9 years for females (van Zyl 2013). The maximum length recorded for this species was 75 cm TL and the maximum weight was 8.1 kg (Smith and Heemstra 1991, South African Underwater Fishing Federation 2012). The maximum age for this species is 48 years (male) (van Zyl 2013).
Chrysoblephus gibbiceps is a slow-growing, long lived species and commercial catch trends show seasonal increases in Struisbaai from May to July (winter) and October to November (early summer) which suggests that this species aggregates to some degree (National Marine Linefish System unpublished data).
Generation length for C. gibbiceps is estimated to be nine years, using the following equation for a gonochoristic fish species: Generation length =Σxlxmx/Σlxmx
