Abstract
Since the market price of fish is variable by different fish kinds as well as according to the amount of catch, various kinds of fish are used for the manufacture of fish-scrap, and cases of falsification, especially of the used fish kinds, are often met with. And accordingly the judgement of the quality of fish-scrap is not an easy task. It has been mostly done by one's experience and no scientific method has been used. At first hand, the identification of the fish kinds used for the fish-scrap is much desired, and for that purpose the present study is attempted. The method to get easy means for the said identification is as follows : I. Identification by bones. Pieces of bones found in the fish-scrap are compared morphologically to those obtained from known fishes which may usually be made into the fish-scrap. Chief bones, such as, dentary, opercle, vertebra, etc, are the ones most available for the purpose, and by that comparison fish kinds used as the material of fish-scrap are able to identify with certainty. Proteolytic enzyme is very useful for the extraction of bones from the fish-scrap. (Figs. 12,13) X-ray photographs are also available for the comparison of bones, as they show clearly the special features for each fish-kind. (Figs. 15-21) II. Identification by scales. Scales of fish found in the fish-scrap is available, as they show special characters for each fish kind by their type, shape, radii, circuli, colour and speckles. (Figs. 22-24) With regard to the fish-meal which is powdered and contains no bones and scales in their natural shape, great difficulty is met with, as morphological and X-ray examinations are not applicable. In such case I think it best to rely upon the serological study, which is now in progress.
