The use of opercular bones in the study of age and growth in Labeo senegalensis from Lake Kainji, Nigeria

Check marks were found on the scales and opercular bones of Labeo senegalensis from Lake Kainji, Nigeria. The scale marks were often indistinct and difficult to interpret, but an attempt was made to determine age from the opercular bones. At least two check marks per year were found on the opercular bones, one of these occurring during June‐July, and the other during January. The relationship between opercular length and fish total length was plotted logarithmically and back‐calculations of length made. Problems of interpretation are discussed in relation to possible causes of ring formation.