Enables channel activity. Involved in defense response to Gram-negative bacterium; glycerol transmembrane transport; and innate immune response. Located in basolateral plasma membrane. Expressed in intestine and pharynx. Human ortholog(s) of this gene implicated in several diseases, including brain edema; inflammatory bowel disease (multiple); and morbid obesity. Is an ortholog of several human genes including AQP3 (aquaporin 3 (Gill blood group)); AQP7 (aquaporin 7); and AQP9 (aquaporin 9).