Involved in the first step of peroxisomal beta-oxidation by catalyzing the desaturation of fatty acid-derived side chains of ascaroside pheromones, which regulates development and behavior (PubMed:29863473). Specifically, shortens indol-3-carbonyl(IC)-ascarosides with 7-carbon (IC-asc-C7) or 9-carbon (IC-asc-C9) side chains and contributes to the shortening of ascarosides with 13-carbon (asc-C13) and 15-carbon (asc-C15) side chains (PubMed:29863473). IC-asc-C7-CoA + O2 = H2O2 + IC-asc-DeltaC7-CoA IC-asc-C9-CoA + O2 = H2O2 + IC-asc-DeltaC9-CoA asc-C13-CoA + O2 = asc-DeltaC13-CoA + H2O2 In contrast to other acyl-coenzyme A oxidases which bind to and are activated by ATP, does not bind ATP. Lipid metabolism; peroxisomal fatty acid beta-oxidation. Homodimer. Expressed in intestine. Belongs to the acyl-CoA oxidase family.