Efek susu skim terhadap kualitas spermatozoa dan persentase fertilitas telur ikan lukas (Puntius bramoides Val, 1842) yang dibuahi spermatozoa pascakriopreservasi = Skim milk effect on sperm quality and fertilization rate of egg lucas fish (Puntius bramoides Val, 1842) fertilized by post cryopreserved sperm