Enables palmitoyl-CoA 9-desaturase activity and stearoyl-CoA 9-desaturase activity. Involved in cellular response to nutrient and monounsaturated fatty acid biosynthetic process. Acts upstream of or within fatty acid biosynthetic process. Is integral component of membrane. Orthologous to human SCD (stearoyl-CoA desaturase). [provided by Alliance of Genome Resources, Apr 2022]