Age and growth of Crystallogobius linearis (von Düben, 1845) (Teleostei: Gobiidae) from the Adriatic Sea

Abstract

Age and growth of the crystal goby Crystallogobius linearis (von Düben, 1845) were investigated by means of daily growth increment counts on the sagittal otoliths. Samples of C. linearis, obtained as by-catch of the Aphia minuta fishery, were collected in a coastal area of the central Adriatic Sea between March and September 1996. Otolith age-readings were carried out on 167 specimens, ranged from 14 to 41 mm of total length, and indicated that the population was composed of individuals from two to seven months old. Growth of both males and females appeared practically linear over the whole size range studied, although in females a slight decrease in growth rate of older specimens was observed. Furthermore, the hatch date distribution of C. linearis, obtained by the backcalculation of the ageing data, indicated a long breeding season of at least eight months. The results of this study indicated that, as reported from literature for most nektonic gobies, the crystal goby is also characterised by a short life span, during which a high reproductive effort is displayed throughout a long breeding season.