Parasite Tags for Marine Fish

Abstract

Parasites of marine fishes as well as those of other animals often exhibit remarkable geographic variations in abundance. Differences may have environmental or physiological explanations, but regardless of their causes, such variations should prove useful to the study of fish populations and migrations. Parasites may serve as identifying fish from a particular area or of a particular age, and natural marks of this kind can be valuable supplements to tagging programs-in fact they may be a method of choice in studying stocks and movements of fish, particularly deepwater ones, that are difficult to tag. Some information about populations and movements of marine fish has already been obtained through studies of parasite distribution and abundance. Parasite tags have been used with profit in studying the continental origin of high seas salmon stocks in the Pacific (Margolis, 1956). A parasitic copepod (Sphyrion lumpi) has provided information about the degree of discreteness of western North Atlantic red-