LDH isozymes in amazon Fish-I. Electrophoretic studies on two species from serrasalmidae family: Mylossoma duriventris and Colossoma macropomum

Abstract

1. 1. LDH electrophoretic patterns of Mylossoma duriventris (pacu) and Colossoma macropomum (tambaqui) showed an identical mobility for the two orthologous A-homotetramers and different mobility for the two orthologous B-homotetramers. This difference is provided by a normal mobility pattern for the former and a reverse one for the later. 2. 2. Tissue specificities and thermal properties were tested and showed similar results for the two species. Like other vertebrates, the Ldh-A product predominates in skeletal muscle tissue and is thermolabile for both species. The Ldh-B product is thermostable and predominates in heart tissue for M. duriventris and, during almost all periods of the year, it also predominates in C. macropomum heart tissue. 3. 3. The activities of the B-subunits showed seasonal variations in C. macropomum heart tissue. This has been correlated with fluctuations in environmental parameters, such as temperature and O2 concentrations, which are a result of differences in water levels. © 1989.