Responsible for the degradation of GM2 gangliosides, and a variety of other molecules containing terminal N-acetyl hexosamines. Degrades chitotriose. Hydrolysis of terminal non-reducing N-acetyl-D-hexosamine residues in N-acetyl-beta-D-hexosaminides. Optimum pH is 5.5. Expressed in coelomocytes and neurons of the pharyngeal region and nerve cord. Expressed throughout the life cycle. Worms show reduced degradation of p-nitrophenyl-beta-N-acetylglucosaminide and no chitotriosidase activity. Belongs to the glycosyl hydrolase 20 family.