I find Chaetonotus novenarius rarely, but regularly. All finds come from the Simmelried. It is striking that all finds were made in the summer months between May and August. This fits in with the description by Schwank (1990) that this species has a maximum in summer.

Chaetonotus novenarius has a conspicuous bundle of 8-9 long spines, which originate just above mid-body and can reach up to the toes. In my population all specimens had  9 of the long spines. At low magnification, Chaetonotus novenarius can be confused with other species with dorsal long spines, such as Chaetonotus aemilianus. However, Chaetonotus novenarius has a characteristic “crown” of thickened scales at the front end of the head (s. figs. 3 b, 5 and 6) and the long spines are inserted in a vase-shaped basis (s. fig. 8). The long spines may have 1 or 2 secondary spines. In my population, all the specimens examined had 2 secondary spines (s. fig. 7), as drawn by Balsamo (s. drawing 2, above). The other body scales are very thin and delicate and are hard to contrasting in DIC. The body scales are triangular and three-lobed, with a short, simple spine. At the posterior end there is a field of elongated oval scales with a keel (s. fig. 9).