ABSTRACT

The different shapes of ossicles are characters of paramount importance in holothurian taxonomy. The method that has been used to isolate these ossicles is to dissolve a small piece of tissue with a small quantity of hypochlorite solution. However, this bleach solution can corrode the calcareous pieces and modify the original shape and dimensions of the ossicles. A new method using a proteolytic enzyme (Pancreatin NF), instead of hypochlorite solution, to dissolve holothurian tissues is proposed. This method was developed by using fragments of body tissues from three species from three different orders: Holothuria grisea Selenka, 1867 (Aspidochirotida), Duasmodactyla seguroensis (Deichman, 1930) (Dendrochirotida) and Synaptula secreta Lopez, 1957 (Apoda). Observations with light and scanning electronic microscopy (SEM) of material prepared using the traditional and the proposed methods was made in order to compare the results. The SEM images show the striking differences in the surface of the ossicles obtained by each method.