Gilthead seabream
Traditionally, gilthead seabream were cultured extensively in coastal lagoons and brackish ponds, particularly in valliculture in northern Italy and in esteros in southern Spain. In the 1980s, however, gilthead seabream were reproduced successfully in captivity and intensive rearing systems were developed, especially in sea cages. Gilthead seabream, whose name refers to a golden band on its head, has become one of European aquaculture’s main fish species.
Latin name – Sparus aurata
Production (EU-27) – 84 590 t (2007); 67 % of global
production.
Value (EU-27) – EUR 363 million (2007).
Main EU producer countries – Greece, Spain, Italy.
Main producer countries worldwide – Greece, Turkey, Spain.
Reproduction
Healthy broodstock used to be selected in their natural setting. Nowadays, seabream eggs are most often obtained from fish reared in fish farms.
It is essential to monitor the number of males and females each spawning season because this hermaphroditic fish changes sex during its lifetime: male for the first three years, then female for the rest of its life. Adult fish are prepared for spawning through photomanipulation (controlling the length of daylight). The male fertilizes the female’s eggs, which float on the water’s surface. They are then collected and transported to incubation tanks, where they hatch 48 hours later.
It is essential to monitor the number of males and females each spawning season because this hermaphroditic fish changes sex during its lifetime: male for the first three years, then female for the rest of its life. Adult fish are prepared for spawning through photomanipulation (controlling the length of daylight). The male fertilizes the female’s eggs, which float on the water’s surface. They are then collected and transported to incubation tanks, where they hatch 48 hours later.
Rearing
Rearing systems for seabass and seabream are similar and are based in the same hatcheries, which are generally independent. Newly hatched larvae are microscopic and half their size is made up of the yolk sac that nourishes them.
This sac contains a wide range of nutritional reserves: proteins, amino acids, glycogens and phospholipids. Six days after hatching, the larvae have absorbed their yolk sac and can start feeding: they are then reared in the same way as seabass fry, first on a diet of microscopic algae and zooplankton (rotifera), followed by artemia, and lastly high-protein inert feed (see the ‘ European seabass’ fact sheet).
This sac contains a wide range of nutritional reserves: proteins, amino acids, glycogens and phospholipids. Six days after hatching, the larvae have absorbed their yolk sac and can start feeding: they are then reared in the same way as seabass fry, first on a diet of microscopic algae and zooplankton (rotifera), followed by artemia, and lastly high-protein inert feed (see the ‘ European seabass’ fact sheet).
Fattening
In extensive systems, gilthead seabream are generally reared with mullets, seabass and eels and feed naturally. In semi-extensive systems, the rearing zone is fertilised to increase natural food availability, with a supplement of commercial feed. In intensive systems, gilthead seabream are fattened with commercial pellets in land-based tanks or, for the greater part of their production, in the Mediterranean and the Canary Islands, in sea cages.
Gilthead seabream reach commercial size after an average period of one and a half years. They are slaughtered by thermal shock: they are placed in vats filled with ice-cold water to shorten their suffering.
Gilthead seabream reach commercial size after an average period of one and a half years. They are slaughtered by thermal shock: they are placed in vats filled with ice-cold water to shorten their suffering.
Consumption
Gilthead seabream are consumed in ‘portions’ and can be marketed in different sizes. They usually weigh between 400 and 600 g and are sold fresh, whole or eviscerated.
The main markets are Italy and Spain, but this fish is increasingly prized in northern Europe. With existing markets starting to show signs of saturation, new processed products are being developed, including large specimens of more than 1 kg (for restaurants) and filleted or frozen products.
The main markets are Italy and Spain, but this fish is increasingly prized in northern Europe. With existing markets starting to show signs of saturation, new processed products are being developed, including large specimens of more than 1 kg (for restaurants) and filleted or frozen products.