P. Kolios, S. Kiritsis, N. Katribusas-1997
Hydrobiologia, 358: 321-325 (from Current Contents)
Abstract:
Juveniles of red porgy (Pagrus pagrus 1758 L.) were experimentally produced in RIOPESCA hatchery during Spring 1992-95.Wild broodstock, weighing from 500 to 1000 g, was caught and brought to the hatchery in summer 1991. They were placed in a 30 m(3) rectangular outdoor broodstock tank with a sea-water flow of 5 m(3) per hour. Salinity ranged from 3.9 to 4.1%, temperature from 13 to 25 degrees C, the stocking density was 4 kg m(-3), and the sex ratio was 1:1.The females spawned spontaneously in captivity producing approximately 200 000 eggs per kg of body weight. The percent of fertilization was between 85-95%. Hatching was completed 85 hours later at 18 degrees C with a hatching percent of 80-90%. The larvae were introduced into a 15 m(3) tank using green water (Nannochloropsis gaditana and Isochrysis galbana) and fed rotifers ( Brachionus rotundiformis), Artemia salina nauplii and metanauplii, and artificial food. After the end of the weaning period (day 80 posthatch) the juveniles reached a weight of 1.4 g with a mean percent of survival of 10%. The fry were transferred to a cage site in which the growout proceeded without particular difficulties. The only problem during growout was the skin coloration, that was darker than that of wild porgies. Red porgies growth in our installations is satisfactory, with fry reaching 360 +/- 12 g within 19 months, with a food conversion rate of 1.8:1, and a 6% mortality.
(Riopesca Aquaculture Western Greece SA, Managouli Focidas 33506, Greece)