Popis: |
Background. The African armoured searobin, Peristedion cataphractum, is a medium sized, gregarious, demersal fish distributed in the Eastern Atlantic and the Mediterranean Sea. Once considered abundant in all the Mediterranean basins, nowadays the species represents an appreciable by-catch of bottom trawlers only in limited areas. The aim of the present was to perform a synthetic analysis of the distribution, abundance, and biological traits of this poorly investigated species. Materials and methods. This paper is based on theinformation recovered from the available “grey” data sources as well as on new original data gathered in 13 experimental bottom trawl surveys carried out off the southern coasts of Sicily from 1994 to 2005. Data recovering and processing regarded distribution, abundance, sex ratio, maturity condition, length structure, and its evolution in time, and growth estimation. Results. Thespecimens of P. cataphractum were present in all investigated areas, with highest abundance in the eastern grounds, between 50 and 800 m, showing a preference for the upper slope (201–500 m). Sexed specimens were almost equally distributed between females and males (overall sex ratio, Sr, between 0.49 and 0.54). Recruits (80–130 mm total length, TL) occurred continuously from September to March, with a peak from late December thru March. The size at onset of sexual maturity (Lm at 50%) was achieved at 191 and 212 mm for females and males, respectively. Growth was evaluated (sex combined) by applying length based methods (LBMs); up five significant modal components were evidenced, the first 2–3 well distinguished. Two sets of the special von Bertalanffy function were derived reflecting juveniles/adult (L∞ = 380 mm, Ky–1 = 0.34 and t0y = –0.76) and adults (L∞ = 313 mm, Ky–1 = 0.28 and t0y = –0.99) growth trajectories. Conclusion. The review performed in the frames of the presently reported study helped to propopse a plausible life history of the investigated stock was proposed. |