HISTOCHEMISTRY OF CARBOHYDRATES, PROTEINS AND LIPIDS DURING SWIMBLADDER DEVELOPMENT IN SEABREAM, SPARUS-AURATA AND SEA-BASS, DICENTRARCHUS-LABRAX

Some histochemical aspects of carbohydrates, proteins and lipids were studied in the swimbladder of seabream, Sparus aurata and seabass, Dic entrarchus labrax. In both species, swimbladder development occurs in two stages: (1) inflation and (2) expansion, respectively. No importan t differences in histochemical distribution of glucidic, proteic and l ipidic macromolecules were observed during the swimbladder development . Glycoproteins containing mannose and/or glucose sugar are present in the swimbladder (gas gland, wall and rete mirabile) of both species, but glycogen was observed only in the gas gland of Sparus aurata swimb ladder. Proteins rich in different aminoacids, except those rich in tr yptophan, as well as carboxyl but not sulphated glycoconjugates were o bserved in both species. Neutral lipids and phospholipids are also imp ortant compounds of the swimbladder. Abnormalities such as hyperinflat ion and non inflation are common for both species, but no important hi stochemical differences were detected in normal and abnormal seabream and seabass swimbladder.