Gambaran Kariotipe Ikan Sinodontis (Synodontis eupterus Boulenger 1901) Untuk Studi Genetika

Abstract

Synodontis eupterus is a popular freshwater ornamental fish. It is unique for its upside-down swimming behavior and its beautifully flowing dorsal fin. Research on Synodontis eupterus had not been conducted before, so the information regarding the karyotype, the number,the shape and the size of chromosome of this fish is unavailable. This study aims to obtain data on the number and the shape of chromosome in Synodontis eupterus. Research was carried out using a desriptive method. Colchicine was applied at a concentration of 0,007% for 8 hours to obtain chromosome at the metaphase stage. Subsequently, the gill tissues were prepared using a hypotonik KCl solution and carnoy’s fixative. Chromosome preparation was performed using the solid tissue technique with fish gills as the sample, followed by giemsa 5% staining. Karyotype data analysis was conducted using Adobe Photoshop CS3 and IdeoKar 1.3 sofware to identify the number, the shape, and the size of the chromosome. The results of this study showed that the chromosomes of Synodontis eupterus consist of 18 pairs of diploid chromosomes (2n=36), comprising 13 metacentric chromosomes, 1 submetacentric chromosome, and 4 telocentric chromosomes.. In Synodontis eupterus, the largest chromosome measurement is 15.47 μm, while the smallest is 4.97 μm. The r value of the largest chromosome is 0.95, with a relative length percentage is 7.75%. The TF% (total from percentage) is 40.90%, Ask% (asymmetry index of karyotype) is 59.09%, Xci (average centromere index) is 0.35 and HCL (total chromosome lenght complement) is 199,21. The chromosomes of Synodontis eupterus find in a normal condition with a high asymmetry index indicate a more advanced stage of evolutionary development