Stolothrissa tanganicae, an endemic clupeid of Lake Tanganyika (East Africa), dominates ring-net and traditional fisheries in most years, cycling from a low in catches in the first half of the year to high abundance in the latter half. From fish sampled in the ring-net fishery and from total catches of Stolothrissa we developed length frequencies by month, assessed monthly growth from modal lengths, and used Ford-Walford plots to assess a yon Bertalanffy growth constant k of 0.21 and maximum length (L∞) of 90 mm. From a length-frequency distribution, calculated monthly age frequencies, and a calculated age frequency in the catch, instantaneous mortality (Z) = 0.43 per month. Peak spawning in Zambia to the south takes place August-December, and from our data on monthly age-class contributions and published sources we concluded that the peak spawning period for Stolothrissa occurs January through April in the northern part of the lake, although recruits of other time origin may appear. A similar lag in biomass increase is probably adapted to timing of wind-induced nutrient upwelling and plankton production.