Lactate dehydrogenase isozymes, gytochrome oxidase activity, and muscle ions of the rattail (Coryphaenoides sp.)

SYNOPSIS. Investigations into the behavior of molecules in organisms occupying unique environments may provide a better insight into the functions of these same molecules in organisms from more common habitats. An organism well suited for such analyses is the rattail (Coryphaenoides sp.), a deep-sea teleost. The photoreceptor cells of the retina are predominantly rods. Although the lactate dehydrogenase A₁, and B₄, isozymes are present in this fish, the E₄ isozyme (found in the retina of many teleosts) is absent in the rattail retina. The rattails possess a lower cytochrome oxidase activity than shallow water fish. The sodium concentration is higher, and the potassium concentration lower in the rattail as compared with surface marine fish. The patterns of molecular synthesis and concentrations in the rattail may be related to such factors as light intensity, hydrostatic pressure, and temperature which exists in the deep-sea environment.