IDENTIFICATION
Slinger are deep bodied fish with a steep forehead. They are pink in colouration and have a distinct blue bar under the eye. The tail has an orange tinge. Slinger reach a maximum length of about 600 mm.
DISTRIBUTION
Slinger are endemic to KwaZulu-Natal and Mozambique and inhabit offshore reefs from 20 m to 100m in depth.
FEEDING
Slinger are opportunistic predators and feed mainly on benthic crustaceans (such as crabs, mantis shrimps and prawns, molluscs (gastropods), and echinoderms (brittle stars and urchins).
REPRODUCTION
Slinger reach sexual maturity at 240 mm fork length (females only). As they grow they change sex from female to male, with sex change occurring at approximately 35 cm fork length. Dominant males set up mating territories on the reef which they defend against other males. Spawning occurs during winter to spring (June to October).
GROWTH
Slinger reach a maximum age of about 15 years. Females mature at about 3 years and change sex at between 5 and 6 years old. There appears to be a spurt in growth after they change sex.
FISHERY
They are one of the most important line fish caught in the KwaZulu-Natal fishery making up 30% of total commercial catch by weight. Slinger have largely replaced species such as seventy four which once dominated catches off KwaZulu-Natal.
Increased effort by both commercial and recreational skiboat fishermen has resulted in considerable pressure being placed on slinger stocks. The catch-per-unit effort (CPUE) has dropped well below 50% of levels when the fishery started and the average size of slinger has decreased. The market has also changed and whereas in the early days there was no market for small fish, today there is increasing demand. There has also been a drastic alteration in the sex ratio of slinger with the current ratio of males : females being 1:20 on the KwaZulu-Natal south coast whereas the ratio is 1:4 in the St. Lucia Marine Reserve, where the capture of slinger and other reef fish is prohibited. It is thought that this skewing of the sex ratio due to fishing pressure may have reduced the reproductive potential of this species.
MANAGEMENT
- Categorised as a restricted species
- Minimum size of 25 cm (50% maturity in females)
- Bag limit of 5 per person per day for recreational and subsistence anglers
- No bag limit for commercial fishermen
Marine protected areas on the north coast are providing a refuge for mature breeding populations of slinger - this probably represents the most important management tool available. Rudy van der Elst and Bruce Mann are acknowledged for the scientific information on which this web page is based.
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