ABSTRACT
Several methods are used in ichthyology to study fish skeletons. The advantage for the student rests on their didactic value for a first-hand understanding of the fish skeleton. The two most common and accessible to everybody are staining and softening the specimen in hot water. A third method, the cleaning of the skeleton by dermestid insects requires special care and facilities. The objective is to stain the calcified skeleton using alizarine red, which gives it a beautiful red or purple colour. The method requires several steps which can be divided into four stages: fixing, digesting, staining, and clearing the specimen, but before starting, it is convenient to prepare the "stock" and "working" solutions according to the following or similar dictionary lines. A methodical procedure is advisable for a clear understanding of the main functional units of the skeleton, as well as each individual bone relationship and position.
