Enables galactokinase activity. Acts upstream of or within galactitol metabolic process and glycolytic process from galactose. Predicted to be located in cytoplasm. Predicted to be active in cytosol. Is expressed in several structures, including alimentary system; cardiovascular system; central nervous system; integumental system; and sensory organ. Human ortholog(s) of this gene implicated in cataract and galactokinase deficiency. Orthologous to human GALK1 (galactokinase 1). [provided by Alliance of Genome Resources, Apr 2022]