The bonga (Ethmalosa fimbriata) is a coastal and estuarine clupeid that is found on the West African coast from Mauritania to Angola.
It has a maximum length of 40 cm, but the common maximum length observed is 30 cm (Bellemans et al., 1988). Spawning of the bonga takes place in waters of salinity greater than 5 percent. The young stay in the hatching area for 4 months to attain a length of 6 cm before moving into the estuaries or lagoons. At the age of 10 months the bonga moves to the spawning fields (Gerlotto, 1979). The length at spawning varies because of the variation in the length at first sexual maturation. This length varies from 8.08 cm in Côte d'Ivoire to 20 cm in Sierra Leone (see Table I).
Figure 1 Bonga (Ethmalosa fimbriata)
Table I Different lengths at sexual maturation observed for bonga
| Country | Source | Length (cm) | |
| Male | Female | ||
| Senegal | Scheffers et al., 1972 | 16 | 17 |
| The Gambia | Scheffers, 1976 | 18.5 | 18.5 |
| Sierra Leone | Salzen, 1958 | 19 | 20 |
| Côte d'Ivoire | Albert and Gerlotto, 1976 | 13 | 14 |
| Albaret and Charles-Dominique, 1982 (Lagoon) | 8.08 | 8.35 | |
| Benin | Gras, 1958 | <10.00 | <10.00 |
| Nigeria | Fagade and Olanyan, 1972 | 10 | 14 |
Source: Albaret, J.J and Charles-Dominique, E., 1982. Doc.Sc.Cent.Rech.Oceanogr. Abidjan Vol. XIII, No. 2, December, 1982: 23-31
After spawning the fishes leave the estuaries or lagoons for the sea. The bonga is generally very tolerant to salinity changes between its hatching and spawning, when higher than 50 parts per thousand salinity is required.
