Abstract

Temnocephala minor Haswell, 1888 lives ectosymbiotically on the surface of the freshwater crayfish Cherax destructor in the Murray-Darling drainages of Australia. Some glands open on the postero-lateral margin and, being moderately refractory to many stains, can be overlooked in whole mounts and sections, and were, in fact, missed by Haswell. Observations were made on living worms with intra vitam dyes, and on whole mounts, wax sections and ultrathin sections using transmission electron microscopy (TEM) to characterise the secretion from these glands and ascertain its mode of manufacture. The function of the glands remains unknown although it appears non-adhesive.