Enables exo-alpha-(2->3)-sialidase activity and exo-alpha-(2->8)-sialidase activity. Involved in ganglioside catabolic process; glycoprotein catabolic process; and negative regulation of neuron projection development. Located in neuron projection and plasma membrane. Is expressed in brain. Orthologous to human NEU4 (neuraminidase 4). [provided by Alliance of Genome Resources, Apr 2022]