For P. khaoyaiensis the chromosome number was 70 for the majority of analyzed cells(Figure 2c), thus, a female karyotype of 34,XX is suggested. In a minority of cells, only 68 chromosomes were detectable, which was most likely an artifact. The analyzed chromosome plates of P. khaoyaiensis included one large, one medium and one small pair of metacentric chromosomes, while the remaining chromosomes were acrocentrics or acrocentrics containing a small short arm. C-positive regions were localized in the pericentric regions of almost all chromosomes. Moreover, in pericentric regions, C-positive stretches were also detected in terminal and intercalary positions of some chromosomes. Among all analyzed embryos, one large chromosome including a large C-positive arm and a small C-negative arm was observed. According to C-banding pattern, no chromosome homologous to it was found (Figure 5a). Subsequent two-color FISH revealed that the large C-positive long arm was enriched for telomeric repeats and repeats homologous to the fragment of 18S rDNA. Furthermore, an erstwhile unidentifiable homologous chromosome was found (Figure 5b). In chromosome spreads of P. khaoyaiensis there were two chromosomes containing cluster of 18S rDNA. They showed the same C-negative arms similar in size, but one of them contained a small short arm, while the other contained a large C-positive arm, both of them enriched for 18S rDNA and telomeric repeats (Figure 5b). In Figure 5c a karyotype is presented; gonosomes were not identified.