Penelitian dilakukan untuk mengetahui pengaruh kombinasi gliserol 6% dengan beberapa konsentrasi kuning telur terhadap kualitas spermatozoa ikan kerapu kertang Epinephelus lanceolatus (Bloch, 1970) pascakriopreservasi. Semen ikan kerapu kertang didapatkan dengan metode pengurutan. Larutan pengencer terdiri atas marine fish ringer, gliserol 6%, dan berbagai konsentrasi kuning telur (0%; 5%; 10%; 15%; 20%; dan 25%). Ekuilibrasi dilakukan selama 10 menit pada suhu 4 ºC. Pembekuan dalam freezer (-20 ºC) selama 48 jam. Pencairan pada suhu 45 ºC selama 30-60 detik. Evaluasi semen dilakukan secara makroskopis (warna, volume, dan pH) dan secara mikroskopis (motilitas, viabilitas, dan abnormalitas) serta kemampuan fertilisasinya terhadap telur ikan kerapu macan. Berdasarkan hasil uji ANAVA yang dilanjutkan dengan uji Tukey, terdapat perbedaan nyata (P>0,05) terhadap motilitas, viabilitas, dan kemampuan fertilisasi spermatozoa ikan kerapu kertang pascakriopreservasi, akan tetapi tidak berpengaruh nyata terhadap abnormalitas spermatozoa pascakriopreservasi (P>0,05). Hasil penelitian menunjukkan bahwa perlakuan kuning telur 15% merupakan konsentrasi optimum karena menghasilkan nilai persentase rata-rata motilitas, viabilitas, dan kemampuan fertilisasi tertinggi masing-masing sebesar 83,64 ± 1,72%, 81,44 ± 2,06%, dan 77,31 ± 1,90%. Nilai rata-rata terendah pada persentase abnormalitas sebesar 21,50 ± 1,20%.

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Research on the effect of combination 6% glycerol and eggyolk as cryoprotectant of giant grouper Epinephelus lanceolatus (Bloch, 1970) spermatozoa quality postcryopreservation. Giant grouper cement is obtained by sorting method. The diluent solution used consist of marine fish ringer, 6% glycerol, and varian egg yolk concentrations (0%; 5%; 10%; 15%; 20%; dan 25%). Equilibration is carried out for 10 minutes at 4ºC. Freezing in the freezer (-20 ºC) for 48 hours. Thawing at 45 ºC for 30-60 seconds. Cement evaluation is carried out macroscopically (color, volume, and pH) and microscopically (motility, viability, and abnormality) and also the ability to fertilize the egg of tigger grouper. Based on the ANAVA statistical test followed by Tukey, there were significant differences effect on motility, viability, and fertilization ability of spermatozoa of giant grouper postcryopreservation (P> 0.05), but abnormality was significantly affected (P <0.05). (P> 0.05). The optimum concentration of egg yolk is 15% because it produces the highest percentage value of motility, viability, and fertilization ability of 83.64 ± 1.72%, 81.44 ± 2.06% and 77.31 ± 1.90% respectively. The lowest average value of abnormalitiy percentage is 21.50 ± 1.20%.