Karyotype studies in thirteen species of fishes

Standardized Karyotype and Idiogram of Two-Spot Glass Catfish, <i>Ompok bimaculatus</i> (Siluriformes, Siluridae) in Thailand by Conventional and Ag-NOR Staining Techniques

“…This is in agreement with the earlier studies conducted in Thailand (Donsakul 1992). Interestingly, it differs from the report of Nayyar (1965) showing a 2n=40 for O. bimaculatus in India, which differs from studies by Das and Khuda-Bukhsh (2007) who showed that this same species in India had 2n=41 and 2n=42 in males and females, respectively. The fundamental number (NF, chromosome arm number) was 90 in both males and females.…”

“…The fundamental number (NF, chromosome arm number) was 90 in both males and females. This is different from earlier studies conducted in Thailand and India (Donsakul 1992, Nayyar 1965, Das and Khuda-Bukhsh 2007. The karyotype was composed of 10 large metacentric, 2 large submetacentric, 4 large acrocentric, 2 large telocentric, 4 medium metacentric, 18 medium submetacentric, 2 medium acrocentric, 2 medium telocentric, and 6 small telocentric chromosomes.…”

“…In Thailand only 11 species of this family have been cytogenetically investigated where studies report the diploid chromosome number (2n) ranging from 40 to 92. Each species has a different diploid number for in-stance, S. phaiosoma 2n=40, S. schneideri 2n=40 (Magtoon and Donsakul 2009), O. bimaculatus 2n=40 (Nayyar 1965), 2n=41 in male, 42 in female (Das and Khuda-Bukhsh 2007), 2n=50 (Donsakul 1992), W. leerii 2n=56 (Donsakul 1996), O. fumidus 2n=60 (Magtoon and Donsakul 2009), B. dinema 2n=62 (Donsakul 1996), K. macrocephalus 2n=62 (Magtoon and Donsakul 2009), K. bicirrhis 2n=64 (Donsakul 1996), M. bleekeri 2n=64 (Donsakul 1992), W. attu 2n=88 (Donsakul 1996) and K. cryptopterus 2n=92 (Donsakul 1992).…”

“…Only 5 previous cytogenetic studies of the genus Ompok have been conducted (Nayyar 1965, Donsakul 1992, Datta et al 2003, Das and Khuda-Bukhsh 2007, Magtoon and Donsakul 2009. Results obtained will increase our basic knowledge of the cytogenetics of O. bimaculatus which could form the basis for future research and provide data to ensure their survival.…”

A New Natural Autotetraploid and Chromosomal Characteristics of Dwarf Snakehead Fish, <i>Channa gachua</i> (Perciformes, Channidae) in Thailand

“…Meanwhile Banerjee et al (1988) revealed that C. gachua in India has 16 metacentric, 10 submetacentric and 52 telocentric chromosomes. No cytologically distinguishable sex chromosome was observed, similar to C. striata ) and other snakeheads (Nyyar 1966, Wattanodorn et al 1985, Banerjee et al 1988, Donsakul and Magtoon 1991, Magtoon et al 2006, Ruma et al 2006. The present study is the first report on its chromosome size.…”