The development of the swim bladder of pikeperch Sander lucioperca (L.) reared in intensive culture

Abstract

The aim of this study was to describe the development of the swim bladder of pikeperch Sander lucioperca (L.) under conditions of intensive culture and to determine when the pneumatic duct regresses. The development of the swim bladder was observed over a 30-day period of larvae culture in a recirculation system. The swim bladder and the pneumatic duct were clearly visible in histological cross sections of 4-day-old larvae. On day 6 after hatching significant changes occurred in the microscopic structure of the swim bladder, e.g. the gas gland and oval primordia appeared. The pneumatic duct gradually atrophied in the larvae with inflated swim bladders between days 11 and 13, while it remained open until day 24-26 after hatching in fish with noninflated swim bladders. The swim bladders of the latter group were irregular in shape and hyperplasia of the epithelium and connective tissues and the presence of macrophags were noted. Pikeperch larvae with noninflated swim bladders also suffered from lordosis and slower growth rates.

CORRESPONDING AUTHOR:

Krystyna Demska-Zakęś, Uniwersytet Warmińsko-Mazurski, Zakład Genetyki Ewolucyjnej, ul. Oczapowskiego 5, 10-957 Olsztyn; Tel./Fax: +48 (89) 5233283; e-mail:krysiadz@uwm.edu.pl