Slinger

IDENTIFYING FEATURES

Slinger are deep-bodied fish with a steep forehead that belong to the family Sparidae. They are pink in color and have a distinct blue bar under the eye. The tail has orange tinges.

Family: Sparidae
Size: 60 cm fork length and weigh up to 4 kg

 

DISTRIBUTION

Slinger are endemic to KwaZulu-Natal and southern Mozambique.

 

HABITAT

Slinger inhabit offshore reefs from 20m to 100m in depth.

 

DIET

Slinger are opportunistic predators which feed mainly on benthic crustaceans (such as crabs, mantis shrimps, and prawns), molluscs (gastropods), and echinoderms (brittle stars, urchins).

 

REPRODUCTION

Slinger change sex from female to male. Large, dominant males probably set up territories on the reef, mate with females entering their territories and defend these against other males.

Spawning occurs during winter and spring (June to October) and both males and females undertake numerous spawning events during each spawning season (multiple spawners).

Males appear to grow quickly after sex change probably as a result of less energy being put into the production of sperm as opposed to eggs.

Length at maturity: 24 cm fork length (females)
Age at maturity: 3 years (females)
Maximum age: 15 years
Reproductive style:  Protogynous hermaphrodites (Change sex from female to male)
Age at sex change: 3-6 years
Length at sex change: 24-35 cm fork length
Male to female sex ratio: 1:20 in KwaZulu-Natal outside marine protected areas

 

CAPTURE

Slinger are one of the most important line fish caught in the KwaZulu-Natal ski-boat fishery making up over 50% of the total commercial catch by weight. Slinger has largely replaced species such as seventy-four which once dominated catches off KwaZulu-Natal.

 

REGULATIONS

Daily bag limit: 5 per person per day
Minimum size limit: 25 cm total length
Closed Season: None
Other Regulations: None
SASSI: Orange list

 

CONSERVATION

Increased fishing effort by both commercial and recreational ski-boat fishermen has resulted in considerable pressure being placed on slinger stocks. The catch-per-unit-effort (CPUE) has declined considerably compared to when the fishery started and the average size of slinger has decreased.

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. However, the slinger population does appear to be showing a positive response to the cuts made in commercial fishing effort between 2003-2006.

Marine protected areas on the north coast are providing a refuge for mature breeding populations of slinger – this probably represents one of the most important management tools available for the conservation of this species.

 

IUCN

Downloadable fact sheet