Kematangan gonad ikan sumpit (Toxotes jaculatrix Pallas 1767) pada salinitas berbeda [Gonad maturity of archerfish (Toxotes jaculatrix Pallas 1767) in different salinity]

Abstract

The archerfish (Toxotes jaculatrix Pallas 1767) has a high tolerance to salinity alteration (euryhaline). However the adaptability of archerfish to salinity alteration has not been followed by the information of gonad maturation. This study was conducted to determine development the maturity of gonad of archerfish that was kept in medium with different salinities. Three concrete tank size 300 x 200 x 100 m3 was used in this study; each of them filled water with different salinity; 0, 12-15, and 30-35 ppt respectively. Fish omitted used in this experiment is 15.06 ± 2.05 cm of total length and 50-70 g of body weight. During six months of experiment, all fish were fed crickets twice a day as ad libitum. The gonads maturity level of female observed by egg diameter measurements that were obtained from cannulation while the gonads maturity level of male observed by means quantity and quality (motility) of sperm which were collected from striping. The results obtained show that the archer fish gonads develop in all salinity. Around 25-30% of female gonads develop until level 3 of Gonads Maturity Levels (TKG) in all salinity, whereas the gonad maturity level of male the highest found in fish reared at a salinity of 30-35 ppt followed 12-15 ppt and 0 ppt respectively 20%, 6% and 7%.

Abstrak

Ikan sumpit (Toxotes jaculatrix Pallas 1767) memiliki toleransi tinggi terhadap perubahan salinitas (eurihalin). Namun kemampuan adaptasi ikan sumpit pada berbagai salinitas belum didukung oleh informasi perkembangan gonadnya. Pe-nelitian ini dilakukan untuk mengevaluasi perkembangan kematangan gonad ikan sumpit yang dipelihara pada salinitas berbeda. Wadah yang digunakan adalah bak beton berukuran 300 x 200 x 100 m3 sebanyak tiga bak, masing-masing di isi air dengan salinitas berbeda yaitu 0, 12-15, dan 30-35 ppt. Hewan uji yang digunakan adalah calon induk ikan sum-pit ukuran 15,06±2,05 cm (bobot badan 50-70 g). Selama enam bulan pemeliharaan, ikan diberi pakan jangkrik dua kali sehari secara ad libitum. Tingkat kematangan gonad (TKG) ikan betina diamati melalui pengukuran diameter telur yang didapat dari hasil kanulasi dan tingkat kematangan gonad ikan jantan diamati melalui kuantitas dan kualitas (motilitas) spermatozoa yang diperoleh melalui pengurutan. Hasil yang diperoleh menunjukkan bahwa gonad ikan sumpit berkem-bang pada semua salinitas media. Sebanyak 25-30% ikan betina mengalami perkembangan gonad hingga TKG 3 pada semua salinitas, sedangkan tingkat kematangan gonad ikan jantan tertinggi didapatkan pada ikan yang dipelihara pada salinitas 30-35 ppt selanjutnya 0 ppt dan 12-15 ppt masing-masing sebanyak 20%, 6% dan 7%.