Common Names: Shire River Tilapia, Malawi tilapia, makumba (Chichewa).

History of Use: Endemic to Malawi and the Shire River system including Lake Chilwa, this species has long been an important component of commercial fish catches. First cultivated in Northern Malawi in the 1950’s, this species has become the backbone of the Malawian aquaculture industry. Currently grown either in monoculture or polyculture (with Tilapia rendalli) by some 3,000 smallholders and two larger-scale commercial integrated aquaculture enterprises in Malawi.

Production Statistics: 10-20 tons per annum.

Where Farmed: Malawi, Southern Africa.

Climate and Environmental Tolerance: tropics, can withstand temperatures of 10-40° C. Spawns at a minimum temperature of 17° C up to at least 30° C. General water quality in ponds for O. shiranus growth were reported by Msiska (1988).

Current Farming Methods: Commercially produced in pond-based systems fed with either duck or chicken manure. Produced in smallholder systems on agricultural by-products. Feeding habits and growth potential similar to closely related tilapias (e.g., O. mossambicus, O. macrochir, O. placidus, O. urolepis). In small ponds, largely omnivorous but targeting phytoplankon and diatoms (Brummett and Katambalika 1996). Pond inputs are normally in the form of agriculture by-products which act mainly as fertilizers and/or supplemental feeds in O. shiranus ponds. In addition, a range of plants which O. shiranus will consume directly was documented by Chikafumbwa et al. (1991). Chikafumbwa (1996) found that an input rate of 50 kg dry matter.ha-1.day-1 resulted in optimal performance. Typical specific growth rates at this input rate are between 0.30 and 0.50 % per day although Brummett and Katambalika obtained 0.90 % day-1 in polyculture with Barbus paludinosus. Survival in ponds is normally around 90%.

Maluwa and Costa-Pierce (1993) found that hapas stocked at a sex ratio of 1 male: 2 females (avg wt females 42 g) and either 0.7, 1.0 or 1.7 broodfish per m2 (harvested every three weeks), produced approximately 5,000, 4,000 and 3,000 fry respectively over 203 days. At a broodstock sex ratio of 1:1 and otherwise similar conditions, Brummett and Noble (1995) produced an average of 2,000 large fry (average weight 0.3 g) per hapa over 133 days. Mhango and Brummett (1997) compared male : female sex ratios of 1 : 1 and 1 : 3 at a fixed stocking density of 1.25 fish per m2 (avg wt 100g) in 200 m2 earthen ponds and obtained 14,000 fry per pond from the 1 : 1 treatment and 12,200 fry per pond from the 1 : 3 treatment over 84 days. Fry per female averaged 112 at the 1 : 1 sex ratio and 65 at the 1: 3 sex ratio. On-farm fingerling production trials found that a 180 m2 pond stocked with 60 male (average 58 g) and 120 females (average 35 g) produced 736 fingerlings of various sizes ranging from 2 to 25 g over 296 days (Brummett and Chikafumbwa 1994).

Processing and Marketing: In Southern Africa, normally sold whole and fresh on smallholder pond banks. When preserved, splitting and smoking is the preferred method. Marketed at any size over 50 g.

Likely Future Trends: Will remain an important species among Malawian smallholders. O. shiranus will also play an important role in the evolution of commercial aquaculture systems in Malawi.

References:

Brummett, R.E. and R.P. Noble. 1995. Aquaculture for African smallholders. ICLARM Technical Report 46. International Center for Living Aquatic Resources Management, Manila, Philippines.

Brummett, R.E. and K. Katambalika. 1996. Protocols for the development of indigenous species: polyculture of indigenous species under Malawian smallholder conditions. Aquaculture Research 27:225-233.

Chikafumbwa, F.J.K. 1996. Use of terrestrial plants in aquaculture in Malawi, p. 175-182. In R.S.V. Pullin, J. Lazard, M. Legendre, J.B. Amon Kothias aned D. Pauly (eds.) The Third International Symposium on Tilapia in Aquaculture. ICLARM Conference Proceedings 41, International Center for Living Aquatic Resources Management, Manila, Philippines.

Chikafumbwa, F.J.K., B.A. Costa-Pierce and J.D. Balarin. 1991. Preference of different terrestrial plants as food for Tilapia rendalli and Oreochromis shiranus. Aquabyte, the Newsletter of the Network of Tropical Aquaculture Scientists 4(3):9-10.

Maluwa, A.O. and B.A. Costa-Pierce. 1993. Effect of broodstock density on Oreochromis shiranus fry production in hapas. Journal of Applied Aquaculture 2(2):63-76.

M’hango, T. and R.E. Brummett. 1997. Fry production of Shire River tilapia, Oreochromis shiranus, at two broodstock sex ratios. Journal of the World Aquaculture Society 28(2):188-192.

Msiska, O. V. 1988. Preliminary studies on the performance of Oreochromis shiranus chilwae in ponds with respect to water quality and temperature, p. 63-68. In R.S.V. Pullin, T. Bhukaswan, K. Tonguthai and J.L. Maclean (eds.) The Second International Symposium on Tilapia in Aquaculture. ICLARM Conference Proceedings 15. International Center for Living Aquatic Resources Management, Manila, Philippines.

Randall E. Brummett