Ultrastructural aspects of functional interest in the ventricular myocardial wall of the antarctic icefish Chaenocephalus aceratus

Abstract

1. 1. The ultrastructural components of the myocardial ventricular wall of the hemoglobinless Antarctic teleost Chaenocephalus aceratus are described. 2. 2. The myocardial wall is of the spongy type and consists of myocytes, granulated non-muscle cells, electron dense interstitial spaces and extensive lacunary spaces. 3. 3. The interstitial space is characterized by abundant dense amorphous material and by microfibrils that exhibit a tubular appearance. 4. 4. The arrangement of the lacunary spaces and the characteristics of the interstitium are discussed in relation with the physiological cardiomegaly of this unique teleost.