Cycles of gonadosomatic index of sea urchins (Paracentrotus lividus, Arbacia lixula) in Urla-Iskele

The sea urchins Arbacia lixula and P. lividus are common on shallow subtidal reefs and live together in the Mediterranean. But P. lividus has been favoured by consumers because of its distinctive aroma and good taste. The gonads are eaten fresh in sauces, soups, creams and omelettes. The development of gonads of P. lividus is its maximum in February and May (8.84%-8.97%). Results indicate that gonad index of P. lividus was calculated between 2.87 +/- 1.02 and 8.97 +/- 0.56. A. lixula gonad index was calculated between 4.28 +/- 1.27 and 6.91 +/- 0.84 in this study. P. lividus gonad index is maximum in May. A. lixula gonad index is maximum in February. 78.52% P. lividus and 21.47% A. lixula of population were observed in Urla-Iskele population.