Subterranean Fishes of the World

3975

2016

Journal of Applied Ichthyology

124-126

33

The karyotype and genome size are basic characteristics of an organism. In an organism, chromosomes are the main carriers of genetic information. The karyotype is the number, size and shape of chromosomes present in medium-term cells of an organism. Genome size refers to the total amount of DNA in one copy of a genome, which is the same as haploid nuclear DNA content (Wolf, Ritter, Atkin, & Ohno, 1969). Varying greatly among species, it is fairly constant within a species. Usually, genome size is estimated by calculating the C-value. The research on karyotype could detect the chromosome mutation and reveal the evolutionary relationship among species (Niu & Cai, 2006). A prior estimation of the genome size is a valuable tool for genomic studies such as whole genome sequencing. China has a rich cavefish fauna. In southwest China, over 10 cavefish species from the genus Triplophysa have been reported (e.g., Li et al., 2008; Romero, Zhao, & Chen, 2009; Zheng, Du, Chen, & Yang, 2009). Cavefishes have evolved constructive and regressive changes in their phenotypes: an increased size and number of specialized mechanosensory organs, eye degeneration and loss of pigmentation (e.g., Jeffery, 2001, 2009). Triplophysa rosa is an endangered cave-dwelling fish found in Wulong County, Chongqing, southwestern China (Chen & Yang, 2005). Thus far, only a very few studies have been carried out on its biology including genetics (Wang et al., 2012; Zhao, Zhao, & Peng, 2014). Many aspects such as cytogenetic and phylogeny are underrepresented. Herein, we studied the karyotype of T. rosa by culturing kidney cells and measured its genome size based on flow cytometry. This is the first report of karyotype and genome size for T. rosa.

1