Despite being less than a millimeter in length, the tardigrade has several distinguishing features to help identify it. The claws are vital to the organism’s make-up, helping them grasp to their substrate of choice and also are one of the key morphological characteristics taxonomists use when differentiating between tardigrade classes. H. dujardini has eight short, un-jointed legs, and as part of the Eutardigrade class, they’re distinguished by two double-claws per leg. The first three pairs of legs have claws placed externally and internally, while the hind legs’ claws are arranged by anterior and posterior placement (Thorp et. al 2010).

The organism may lack respiration and circulation organs, but it does contain a complex, annelid-type nervous system (Eisenhour et. al 2012). Furthermore, tardigrades have digestive system composed of three parts: the foregut, midgut, and hindgut. Both the foregut and hindgut have a cuticular lining; with the hindgut having a further division for an anterior hindgut, AKA the rectum.

The unique feature is their cuticle; a water-permeable tool that covers the body and lines the fore- and hindgut. The cuticle is secreted from the underlying epidermis and is composed of three layers: the epicuticle, intracutile, and procuticle; with the inner layer containing chitin. This also aids in taxonomy purposes as it may have various pigmentations per species to help differentiate, though the H. dujardini is a colorless species, as the color in photos come from a filter (Thorp et. al 2010). The colors seen are merely coloration from intestinal contents or body cavity cells.