Effects of sea bloom, chattonella antiqual, on gill primary lamellae of the young yellowtail, seriola quinqueradiata

Abstract

Histological and histochemical alterations on gill primary lamellae of the teleost, young yellowtail (Seriola quinqueradiata), affected by the sea bloom (Chattonella antiqua) were studied and causative factors responsible for fish death were considered in the present work. A significant loss of mucous goblet cells on the afferent ridges occurred within about one hr. Among the remainder, mucous cells located on the afferent ridge of the basal part of the gill primary lamellae were markedly impaired (64% decrease in number). For TEM preparation, hyaline degenerations of the mucous cell membrane were observed. Histochemically, these mucous goblet cells contained neutral and acid glycoproteins. The cell layer on both ridges exposed to sea bloom appeared to be thinner than that of the control. The cell body of the internal multilayered mass was shrunk and intercellular spaces were markedly expanded. These edematous gill lamellae might be caused by the disappearance of the mucous coat, leading to locally impaired osmoregulations. As a result, gas exchange on the gill lamellae might be disturbed. © 1983, JAPAN SOCIETY OF HISTOCHEMISTRY AND CYTOCHEMISTRY. All rights reserved.