Enables alpha-mannosidase activity and mannose binding activity. Predicted to be involved in cellular protein modification process. Predicted to act upstream of or within learning or memory and mannose metabolic process. Located in lysosome. Human ortholog(s) of this gene implicated in alpha-mannosidosis. Orthologous to human MAN2B1 (mannosidase alpha class 2B member 1). [provided by Alliance of Genome Resources, Apr 2022]