A New Method for Making SEM Preparations of the Tardigrade Buccopharyngeal Apparatus

Abstract

The buccopharyngeal apparatus of several species of tardigrades, including both heterotardigrades and eutardigrades, has been prepared for scanning electron microscopy (SEM) by using a new method developed and refined for this purpose. The buccalpharyngeal apparatus from three well-known species are described in detail and preliminary attempts to interpret the function of some of the structures are presented. The chosen species are used as examples and the new findings are compared to studies from the literature. The species used are: Echiniscoides sigismundi, Halobiotus crispae and Milnesium tardigradum. A redescription of the buccopharyngeal apparatus, in particular the stylets, the stylet supports, the stylet sheaths and their interrelationships, is presented for each species. For H. crispae the cuticular elements of the pharynx are also redescribed from this material. The potential for new information available with this method is discussed, together with the possible artifacts and difficulties the method may cause.