On the Chemical Composition of some Mucous Substances of Fish.

Abstract

The mucous substances of some fishes have been studied. The predominant component of the external surface mucus seems to be a simple protein, in the case of myxinoids a protein there are also small, varying amounts of nucleic acid and glycoproteins. The glycoproteins contain hexosamine, galactose, fucose, and sialic acid, and thus seem to be of the same types as are present in mucous secretions of other vertebrates. In addition to ribose (nucleic acid) and in some cases small amounts of fucose, and/or glucose, the fish-roe preparations contained hexosamine, galactose, mannose, and sialic acid as monosaccharide constituents. The carbohydrate moiety probably forms the substantial part of the jelly coat of the roe.