Fig. 1. Graphic illustration of the sites where lamellar diameter (d), height of protruding lamellae (h and H) and basal length of protruding lamellae (l and L) were measured in (A) normoxic and (B) hypoxic fish. Lowercase letters denote measurements in normoxia, and uppercase letters denote measurements in hypoxia. ILCM, interlamellar cell mass (see text for explanation).