Three of these were difficult to interpret and thus omitted from the analyzes. The occurrence of a transparent or opaque zone at the otolith edgs was examined and the result for the percentage occurrence of transparent zones throughout the year are presented in Figure 1. Opaque zones were notes mainly during the summer months, with maximum occurrence in June and July (96%), whilst the majority of transparent zones occurred between October and April with 100% transparency recorded in November and February. The zones therefore appear to be laid down annually.