Enables stearoyl-CoA 9-desaturase activity. Involved in innate immune response; long-chain fatty acid biosynthetic process; and post-embryonic development. Predicted to be located in endoplasmic reticulum membrane. Expressed in hypodermis. Human ortholog(s) of this gene implicated in autosomal dominant nonsyndromic deafness 79. Is an ortholog of human SCD (stearoyl-CoA desaturase) and SCD5 (stearoyl-CoA desaturase 5).