Age, growth, reproduction and feed of longnosed skate, Dipturus oxyrinchus (Linnaeus, 1758) in Saros Bay, the north Aegean Sea

The age, growth, reproduction, and feeding of longnosed skate (Dipturus oxyrinchus) were studied using 179 specimens from the Saros Bay (North Aegean Sea) between March 2005 and December 2007. Composition was 49.7% females and 50.3% males. Total length of females ranged from 14.9 to 100 cm (disc width, 9.8-65 cm), and of males from 15.2 to 86.5 cm (disc width, 10-57.5 cm). Total length-weight and disc width-weight relationships are described by the equations W = 0.0008*TL3.35 and W = 0.0043*DW3.29, respectively. The age data, derived from vertebrae readings, were used to estimate the growth parameters of the von Bertalanffy equation: L-infinity = 256.46 cm, K = 0.04 year(-1), t(0) = -1.17year. The maximum age was 9 years. Males matured at 64-65 cm (disc width, 43.5 cm) and females at 82-83 cm TL (disc width, 53 cm). The stomach contained mainly Parapenaus longirostris, IRI: 93.47%.