First cytogenetic study of the Somphong’s rasbora (Trigonostigma somphongsi) (Perciformes, Cyprinidae), a critically endangered species in Thailand


  • Surachest Aiumsumang Biology Program, Faculty of Science and Technology, Phetchabun Rajabhat University
  • Chavalit Vidthayanon Scientific Committee. SuebNakasathien Foundation, 140 Tiwanon Road, Bang Kraso Subdistrict, Mueang Nonthaburi District, Nonthaburi Province 11000, Thailand
  • Sitthi Kulabtong Faculty of Agro-Industrial Technology, Rajamangala University of Technology Tawan-ok Chantaburi Campus, Chantaburi Province 22210, Thailand
  • Alongklod Tanomtong Program of Biology, Faculty of Science, Khon Kaen University, Muang, Khon Kaen 40002, Thailand
  • Sumalee Phimphan Biology Program, Faculty of Science and Technology, Phetchabun Rajabhat University



Karyotype, Chromosome, Trigonostigma somphongsi


The first chromosome study of Trigonostigma somphongsi (Meinken,1958) from Thailand. Specimens were collected from Pak Phli District, Nakhornnayok Province, central Thailand. The mitotic chromosomes were directly prepared from kidney tissues of two males and two females. Conventional staining and Ag-NOR banding techniques were applied to stain the chromosomes. The results shown that diploid chromosome number of T. somphongsi was 2n=50, the fundamental numbers (NF) were 92 in both male and female. The types chromosomes consisted of 10 metacentric, 20 submetacentric, 12 acrocentric and 8 telocentric chromosomes. The result also exhibited that the interstitial nucleolar organizer regions (NORs) were clearly observed at the short arm of chromosome pair 2. The karyotype formula could be deduced as: 2n (diploid) 50=10m+20sm+12a+8t.


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How to Cite

Aiumsumang, S., Vidthayanon, C., Kulabtong, S., Tanomtong, A., & Phimphan, S. (2024). First cytogenetic study of the Somphong’s rasbora (Trigonostigma somphongsi) (Perciformes, Cyprinidae), a critically endangered species in Thailand. Caryologia, 76(4), 3–8.




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