Gilthead Seabream Farming: A Production Guide

How gilthead seabream (Sparus aurata) is farmed: protandrous reproduction, Mediterranean sea-cage culture, hatchery larviculture, feeding and growth to market, and main diseases.

Overview

Gilthead seabream (Sparus aurata) is, with European seabass, one of the leading farmed marine fish of the Mediterranean. A member of the family Sparidae, it is native to the eastern Atlantic and the Mediterranean. Production was negligible before the late 1980s but grew into a major industry; Mediterranean seabream output reached well over 250,000 tonnes by 2019, with Türkiye and Greece the largest producers.

Reproductive biology

Gilthead seabream is a protandrous hermaphrodite: individuals mature first as males, typically by about two years of age, and some later change sex to become females in subsequent cycles, influenced by social and growth factors. Hatcheries manage broodstock with this sex change in mind to ensure enough females and good-quality eggs for seed production.

Biology and tolerance

Seabream is a euryhaline species that feeds mainly on shellfish and other invertebrates, with some plant material. It is well adapted to intensive rearing in both cages and ponds, but it is sensitive to cold, with a reported lower lethal temperature around 4 °C, which restricts cage farming to warmer Mediterranean waters. It reaches a maximum of about 70 cm but is harvested far smaller.

Culture systems and larviculture

Most seabream is grown in floating sea cages, with tanks and coastal lagoons also used. Seed is produced in hatcheries, where larvae are first fed live rotifers (Brachionus plicatilis) and then Artemia, both enriched, before weaning onto formulated microdiets. As with seabass, live feeds must be kept clean because rotifers and Artemia can carry pathogens into the larval tanks.

Feeding and growth

Grow-out uses high-protein formulated marine pellets suited to the species' largely carnivorous diet. Seabream is grown to a market size commonly around 300 to 500 g for whole-fish sale, with growth rate and time to market depending on water temperature. Because it tolerates intensive conditions and accepts pelleted feed well, it suits cage and tank production at commercial scale.

Main diseases

Important diseases of farmed seabream include bacterial pasteurellosis (photobacteriosis, Photobacterium damselae subsp. piscicida) and vibriosis, viral nervous necrosis (betanodavirus), and parasites such as the intestinal myxozoan Enteromyxum and the gill monogenean Sparicotyle chrysophrii. Skeletal deformities can also reduce quality. Good husbandry, biosecurity, vaccination where available and clean larviculture are the main controls.