Sex-ratio, length-weight relationship, condition factor (n = 859) and the food habit (n = 764) ofrnC. gariepinlls were studied in Lake Langeno from monthly samples collected using hook andrnlines between April 2000 and October 2000.rnFemale to male sex-ratio was in favour offemales in the total sample (1041: 1) and in both seasonsrnof low water-level (1.29:1) and high water-level (1.53:1). Sex-ratio was not significantlyrndifferent from 1: 1 in five of the eight length classes used for the study. ill three of the lengthrnclasses (between 25 cm and 54 cm, TL), females were at least 1.53 times more numerous thanrnmales.rnThe relationship between total length (range: 28 to 104 cm) and total weight (range: 150 to 8000rng) was found to be curvilinear and statistically significant (R2=0.955, P80%) in those below 54 cm TL, and for fish (20-60%) above 65rncm TL. Numerically, crustaceans contributed more than 90% for each length group but theirrncontribution was below 90% for C. gariepilllls above 84 cm TL. The numerical contribution ofrninsects and fish increased for C. gariepinlts above 84 cm. Gravimetric contribution ofrncrustaceans was relatively high (10-15%) for C. gariepinlls between 45 and 74 cm TL, and that ofrnfish (about 10%) for large (>84 cm TL) C. gariepilllls. The weight contribution of insects w!!srnabout similar for all size groups of C. gariepinlls caught in the study. The results suggestesl thatrnas C. gariepilllls grows larger it consumes progressively more fish.rnThe ratio between prey (0. lliloticlIS) length and predator (c. gmiepill11s) length varied greatly.rnAbout 50% of the C. gmiepilllls had ingested tilapia whose length was between 1/1 oth and 1I30tlrnâ€¢rnof their own length. A few individuals had ingested tilapia whose length was either above 1I5thrnor below 1I30th of their length.rnFrequency of C. gariepilllls with empty stomach was quite low (0 to 2.2 %) in samples takenrnbetween April and June, which was coincident with period of low water level. In contrast, thernfrequency was high (9.5 to 20%) in July, August and October. In general, about 95% of the totalrnnumber of empty stomachs were recorded during the season of high water level. This coincidedrnwith the period when C. gariepilllts ingested more fish as compared to the other period.rnThe relative importance of fish to the diet of C. gariepilllls was more pronounced during thernseason of high water level. Crustaceans and insects, however, were equally important throughoutrnthe study period. .