Chromosome Aberrations in the Karyotype of the Southeast Asian Mangrove Frog Fejervarya cancrivora (Gravenhorst, 1829) from Luzon Island, Philippines

Chromosome analysis of 5, 100 bone marrow cells of F. cancrivora revealed that this species possessed an asymmetrical karyotype with diploid number 2n = 26 typical of frogs belonging to the Genus Rana. Nombre fundamental (NF) was 52, consisting of 26 homomorphic chromosomes. Karyotype consisted of three (3) pairs of metacentric and ten (10) pairs of sub-metacentric chromosomes. Sex chromosomes were not morphologically distinct with regard to size and structure. Testis tissue preparations from male specimens showed 26 chromosomes in spermatogonia. Primary spermatocyte at meiotic metaphase ? I (at diakinesis), and secondary spermatocyte at meiotic metaphase - II consisted of 13 ring- and 13 haploid chromosome pairs. Nucleolar Organizer Region (NOR) was detected at the q-arm of chromosome pair 9. The karyotype formula of F. cancrivora was determined to be: 2n (26) = L5sm + S2sm + S1m + S2sm + S1m + S1sm + S1m. Chromosome aberrations were scored for 0.4% of the cells analyzed. The most frequent aberration was the gap, followed by the break and minutes. Gonadal cells did not manifest any aberrations in their chromosomes. F. cancrivora could become a biological monitor to evaluate pollution and environmental degradation similar to recent work undertaken on Fejervarya limnocharis.