Swimbladder pathology during larval development of turbot (Scophthalmus maximus L.)

With the aim of elucidating the causes of the high mortality of turbot (Scophthalmus maximus L.) larvae during development, histopathological studies were carried out and the role of the swimbladder in turbot larval pathology was investigated. Several batches of 1 to 90-d-old larvae from a commercial hatchery were sampled during the course of 3 years. Alterations were observed in swimbladders mainly during developmental stages 2, 3, and 4. The main pathological problems observed were: inflation disturbances, malformation of gas gland and rete mirabile, pneumatic duct dystrophy, and swimbladder invasion by bacterial cells. These pathologies were described in association with organogenesis disturbances in early stages of development and with the presence of enteric flora. The origin of swimbladder alterations and their significance on turbot larvae survival are discussed.

Article from Marine Science Symposia Vol. 201 - "Mass rearing of juvenile fish". Symposium held in Bergen, 21-23 June 1993. To access the remaining articles please click on the keyword "MSS Vol. 201".