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The Workshop on age validation studies of small pelagic species (WKVALPEL) fo-cused on validating ageing criteria for small pelagic species (anchovy, horse mackerel, chub mackerel, mackerel and sardine). The aim of the workshop was to collate information on existing ageing protocols and to use these to support development of a validated protocol to better standardize age estimates. One of the main sources of error affecting ageing precision is the discrimination bet-ween the false ring and annulus. An ageing process follows a number of typical steps. First, an ageing methodology is established, based on scientific information, to obtain age data for a particular species. Once age results are available, some analysis is re-commended to improve precision among different readers and/or readings. The next step is to perform other studies that offer independent results used to support, or not, an accepted ageing methodology. Several matching and independent results help to corroborate certain ageing criteria. Each study determines how precision and/or trueness are enhanced. In general, these methods are included in indirect or semi-direct validation categories, as true ages are not actually known in any of them. Some other methodologies, usually more complex and costly, are considered strictly as validation experiments, as results approach to real ages. Tagging-recapture experiments and rearing in captivity are included within this category. The latest available information on ageing data (precision and/or validation studies) was presented for a number of different species of small pelagics. Methods highlighted included marginal increment analysis (MIA), marginal analysis (MA), length frequency distribution analysis (LFDA) and back calculation (BC). A synthesis table of the last annual growth workshops and exchanges by species is also presented. The goal, for each species (Engraulis encrasiculus, Sardina pilchardus, Clupea ha-rengus, Sprattus sprattus, Scomber

The age and growth of bogue (Boops boops), collected in four areas off the Tunisian coast, were determined by studying growth marks on cross-sectioned otoliths. This calcified structure was chosen because the legibility and regularity of its growth mark patterns appeared to be more reliable than those of other skeletal elements. Opercula and fin rays were rejected because of intense bone remodeling, vertebrae because of numerous minute marks unrelated to cyclic events, and scales because counting of annuli seemed very unreliable, particularly in old specimens. Scales consistently had the highest average percent of error. Marginal zone analysis indicated that the hyaline zone in bogue otoliths was deposited yearly from November to April. Increase of length was determined and length-age data were fitted to Von BERTALANFFY equations. Comparisons of length increases of specimens from the four areas suggest two growth pools with greater increases in the north and east than in the Gulf of Tunis and the south. Relationships between growth and geographical distribution indicated the importance of environmental conditions especially water temperature and food availability, although the role of genetic and/or epigenetic factors could not be excluded.

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