Enables carbonate dehydratase activity. Predicted to be involved in bicarbonate transport and one-carbon metabolic process. Predicted to act upstream of or within carbon dioxide transport and regulation of pH. Located in membrane. Is anchored component of plasma membrane. Is expressed in cardiovascular system; genitourinary system; nervous system; and tail. Human ortholog(s) of this gene implicated in retinitis pigmentosa. Orthologous to human CA4 (carbonic anhydrase 4). [provided by Alliance of Genome Resources, Apr 2022]