Age and growth of the common goby, Pomatoschistus microps, on the south coast of England

Abstract

Seasonal changes in scale appearance and body growth pattern have been studied in a Teign Estuary (Devon) population of the common goby, Pomatoschistus microps (Kroyer), with additional material from St. Anthony, on Gillan Harbour, Cornwall. Examination of caudal peduncle scales showed similarity in annulus formation with other populations earlier investigated around the British Isles. The time of scale annulus formation in the Teign estuary was established from monthly changes in mean terminal sclerite width. After the first winter of life, an annulus of narrow sclerites is produced on resumption of growth in spring, and a second annulus laid down in summer between early June and August, corresponding to growth retardation during the peak of the long breeding season (April to August). The growth pattern shows a period of rapid growth in immature fish during the first summer and early autumn of life and declines or ceases in late autumn and winter. Vigorous resumption of growth in spring and early summer is followed by a decline in growth rate during the peak breeding season, and then growth recovery in September and October. Change in monthly mean terminal sclerite width of scales reflects somewhat earlier changes in somatic growth. Back-calculated growth suggests a static population during the breeding season. Various influences on growth are noted, including reproduction and scale regeneration.