Alternative species for aquaculture

Catfish, silver barbel and other fish have farming potential, but there are obstacles.

Alternative species for aquaculture
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Many of these columns have dealt with tilapia, and some readers may wonder why trout, catfish and others species seem to have been ignored. Needless to say, that was never my intention and this issue I want to take a brief look at the viability of several other species.

Trout aquaculture is, of course, so well-established in South Africa that it needs no introduction, and will not be described in any detail here. Part of its popularity lies in the fact that this fish is so easy to produce. Anyone interested in farming with trout should approach the main players directly to benefit from their wealth of local knowledge.


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During the 1980s and 1990s there was a surge in research and activity in the catfish industry. This centred on the indigenous sharp-tooth catfish (Clarias gariepinus), with there was interest in hybridisation with the closely-related vundu (Heterobranchus longifilis) to produce fast-growing ‘crossbreeds’.

But commercial production never took off, partly because the industry was research- and not market-driven. Several farms successfully produced catfish in large quantities, but failed to market it properly. By contrast, catfish culture took off in Nigeria as a cottage industry – and the country produces significant quantities of the fish to this day.

The 1980s and 1990s also saw the birth – and demise – of high-tech aquaculture systems for intensive fish production. The infamous Mega Fish systems were imported into South Africa – mainly for catfish culture – and soon local manufacturers were rushing to emulate their highly complex filtration and plumbing designs. One by one they failed, testimony to the fact that such systems have little place in African aquaculture.

Meanwhile, the provincial nature conservation departments halted production of trout, bass and tilapia fingerlings in the 1990s. Difficulties in obtaining permits to stock with exotic species such as trout and bass have no doubt mitigated against private hatcheries filling this void again.

Silver Barbel

A freshwater species that may have great aquaculture potential is the silver barbel (Schilbe intermedius) found in the warmer waters of the Limpopo catchment and northern KZN. Growing to 1,3kg in the wild and making excellent eating, this species is an attractive option due to its marketability. Free of scales and fine intramuscular bones, it deserves to be the target of renewed research.


Asian carp such as the common, grass and silver carp were thought to hold aquaculture potential for many years due to their wide temperature tolerances. But their poor acceptance as eating fish doomed them for commercial production, and despite much research carried out at the old Gariep Dam hatchery during the 1970s and 1980s, nothing long-term was achieved.


Gariep Dam has recently been re-vamped as part of an agreement with China. But since it has been designed as a carp and tilapia hatchery in one of the coldest parts of the country during winter, one can only wonder at the rationale behind this expensive venture.

With the current decline of our nine indigenous yellowfish species in so many catchments, it would surely have made more sense to use this facility to produce yellowfish for sport-fishing and to boost numbers in the wild.

Nicholas James is an ichthyologist and hatchery owner. Email him at [email protected]. Please state ‘Aquaculture’ in the subject line.