First Report of NOR Polymorphism and Chromosome Analysis of John's Snapper, <i>Lutjanus johnii</i> (Perciformes, Lutjanidae) in Thailand

Abstract

SummaryThe present study reports the first finding of the NOR (nucleolar organizer region) polymorphism and chromosome analysis in the John's snapper (Lutjanus johnii) from Thailand. Kidney cell samples were taken from four male and four female fish. Mitotic chromosome preparations were conducted using the standard squash technique, as well as directly from kidney cells. Metaphase spreads were performed on microscopic slides and then air-dried. Conventional and Ag-NOR banding techniques were applied to stain the chromosome. The results showed that the diploid chromosome number of L. johnii was 2n=48, and the fundamental number (NF) was 48 in both male and female. Karyotpes were present as 28 large telocentric, 16 medium telocentric, and 4 small telocentric chromosomes. No strange-sized chromosomes related to sex were observed. The results indicated that the long arm subcentromeric of the telocentric chromosome pair 1 showed clearly observable NORs (satellite chromosomes). In addition, a heteromorphism of one female had differentsized NORs in chromosome pair 1 (1a1b), while three females and four males had equal-sized NORs in chromosome pair 1 with a homomorphism (1a1a). The karyotype formula for L. johnii is as follows:2n ( The family Lutjanidae (lutjanid fish), or snappers, is a family of perciform fishes, mainly marine but with some members living in estuaries and entering freshwater to feed. Some of them are important food fish. Species from the family Lutjanidae represent one of the major resources for marine fishery. Lutjanid fish are widespread over the Atlantic, Pacific, and Indian oceans. Fishes of the family Lutjanidae occur in tropical and subtropical seas from shallow waters to depths of approximately 550 m. This family comprises 17 genera with about 105 species, and the genus Lutjanus with 64 species is the largest genus including over half of the species in this family (Nelson 2006).In spite of the high number of species and its worldwide distribution, the family Lutjanidae has been little investigated, and contradictory results have been obtained concerning the phylogenetic relationships and the taxonomic status of some of its genera and species. For example, the validity of the genus Ocyurus has been extensively discussed (Chow and Walsh 1992, Domeier and Clarke 1992, Loftus 1992, leading some authors to propose the synonymization of genus

NOR Polymorphism and Chromosome Analysis of Banggai Cardinalfish, <i>Pterapogon kauderni</i> (Perciformes, Apogonidae)

“…exodon (Paintner-Marques et al 2002), Apareiodon affinis (Jorge and Filho 2004), Aphanius fasciatus (Vitturi et al 2005), Prochilodus lineatus (Gras et al 2007), B. aff. iheringii (Capistano et al 2008), Puntioplites proctozysron (Supiwong et al 2012), and Lutjanus johnii (Phimphan et al 2013).…”

Comparative cytogenetic analysis of fishes in the genus Trichopodus (Osphronemidae) in Thailand

“…The relative length (RL), the centromeric index (CI), and standard deviation (S.D.) of RL and CI were calculated (Phimphan et al 2013;Pinthong et al 2017;Juntaree and Supiwong 2020). The CI (q/p) between 0.500-0.599, 0.600-0.699, 0.700-0.899, and 0.900-1.000 were described as metacentric (m), submetacentric (sm), acrocentric (a), and telocentric (t) chromosomes, respectively (Saenjundaeng et al 2018a,b;Pissaparn et al 2020;Phimphan et al 2020).…”

A Discovery of Nucleolar Organizer Regions (NORs) Polymorphism and Karyological Analysis of Crystal Eye Catfish, <i>Hemibagrus wyckii</i> (Siluriformes, Bagridae) in Thailand

“…exodon (Paintner-Marques et al 2002), Apareiodon affinis (Jorge and Filho 2004), Aphanius fasciatus (Vitturi et al 2005), Prochilodus lineatus (Gras et al 2007), B. aff. iheringii (Capistano et al 2008), Puntioplites proctozysron (Supiwong et al 2012b) and Lutjanus johnii (Phimphan et al 2013). Therefore, different karyotypes are found even in small and isolated populations of these species.…”