Chromosome study of Rasbora trilineata and Rasbora borapetensis (Cyprinidae, Cypriniformes): Reveal by conventional staining technique

Abstract

The present study aims to construct the karyotype and idiogram of two Rasbora, namely Rasbora trilineata and R. borapetensis. Specimens were collected from Salween, Song Kharm, Mae Khlong basin and Sirindhorn Peat Swamp Forest, Thailand. Fish chromosome preparation was prepared directly from renal cells. Conventional staining technique was applied to stain the chromosomes with Giemsa’s solution. The results showed that two species the number of diploid chromosomes is 2n=50. The fundamental number (NF) of R. trilineata is 100, while R. borapetensis is 98. The types of chromosomes of R. trilineata were 12 metacentric, 24 submetacentric and 14 acrocentric chromosomes, and R. borapetensis eight metacentric 18 submetacentric, 20 acrocentric and four telocentric chromosomes. The karyotype formula are as follows: R. trilineata 2n (50) = 12m+24sm+14a, R. borapetensis 2n (50) = 8m+18sm+20a+4t.