KERAGAMAN GENETIK DAN BIOREPRODUKSI EMPAT POPULASI IKAN MATA MERAH (Puntius orphoides Valenciennes, 1842)

Abstract

Ikan mata merah merupakan ikan konsumsi yang berkerabat dekat dengan ikan tawes yang terdistribusi luas di kawasan tropis. Analisis keragaman genetik dan performa reproduksi ikan mata merah, baik jantan maupun betina belum tersedia secara lengkap dan valid. Tujuan penelitian ini adalah untuk menentukan keragaman genetik ikan mata merah dari berbagai lokasi, dan mengkaji bioreproduksinya. Ikan sampel yang diperoleh dari nelayan dan pengumpul di empat lokasi berbeda yaitu: Jawa Barat (Tasikmalaya dan Cianjur), Jawa Tengah (Purwokerto), dan Jawa Timur (Umbulan, Pasuruan), ditampung di Balai Benih Ikan lokal, kemudian ditransportasikan ke Instalasi Plasma Nutfah, Cijeruk, Bogor. Sampel ikan dari berbagai ukuran digunakan untuk analisis keragaman genetik melalui analisis morfometrik dan RAPD, sedangkan untuk kajian bioreproduksi ikan yang digunakan adalah calon dan induk ikan mata merah jantan dan betina. Hasil analisis menunjukkan bahwa keragaman genetik populasi Purwokerto dan Umbulan memiliki perbedaan dengan nilai sharing component intraspesies tertinggi, yaitu 100,0%. Polimorfisme empat populasi ikan mata merah berkisar antara 1,92%-17,30% dengan kisaran tingkat heterozigositas 0,0088-0,0678. Populasi Purwokerto memiliki jarak genetik terjauh (0,0678) dari populasi lainnya. Pada pengamatan kinerja reproduksi hanya dua populasi yang matang gonad dan bisa dipijahkan, yaitu populasi Tasikmalaya dari 10 ekor matang gonad, tiga ekor berhasil memijah, dan Cianjur dari sembilan ekor matang gonad, tiga ekor berhasil memijah dengan nilai derajat pembuahan kedua populasi sebesar 100% dan derajat penetasan yang masih cukup tinggi Tasikmalaya 84,32 ± 7,38a% dan Cianjur 73,15 ± 3,78a%. Volume sperma ikan jantan diperoleh sebanyak 0,1 mL; dengan jumlah spermatozoa sebanyak 75 x 108 sel.

Red-eye fish is a fish species closely related to tawes/silver barb/Java barb and widely distributed in tropical regions. As of now, information on genetic diversity and reproductive performance of red-eye fish, both male and female, have not yet been completed. Thus, this study was conducted to determine the genetic diversity of red-eye fish populations from different locations and study their bioreproduction. Live fish were obtained from fishermen and collectors in four different areas namely West Java (Tasikmalaya and Cianjur), Central Java (Purwokerto), and East Java (Umbulan, Pasuruan). The collected fish were temporarily stored in each local fish seed center before transported to the Germplasm Installation, Cijeruk, Bogor. Fish samples of various sizes were used for genetic diversity analysis through morphometric analysis and RAPD. In bioreproduction observation, the fish used were prospectively matured and matured male and female of red-eye fish. The results of the genetic study showed that the Purwokerto and Umbulan populations have genetic diversity differences with the highest intraspecies sharing component value of 100.0%. The polymorphism of four red-eye fish populations ranged from 1.92%-17.30% with a range of heterozygosity levels of 0.0088-0.0678. Purwokerto population has the farthest genetic distance (0.0678) from the other populations. The observation of reproductive performance found only two populations having mature gonad fish and could subsequently be artificially spawned. The populations were Tasikmalaya population with ten mature gonad fish, of which three fish successfully spawned and Cianjur population with nine mature gonad fish, of which three successfully spawned. The fertilization rate of the two spawned populations was 100%. The hatching rateof eggs from Tasikmalaya and Cianjur populations were relatively high of 84.32 ± 7.38a% and 73.15 ± 3.78a%, respectively. The maximum volume of sperm produced by each male fish from both populations was 0.1 mL, with the total number of spermatozoa of 75-108 cells.