An idiogram on pachytene bivajents with high resalution multiple bands of Epinephelus malabaricus

Epinephelus malabaricus (Perciformes, Serranidae), a rare marine commercial fish inhabits in the warm-water reef along the southeast coast of China. In the present study, well-spread pachytene bivalents with multiple high-resolution bands were obtained after the testes were treated with a hypotonic alkaline solution and a high-chloroform fixative solution, showing that the number and characteristics of band in each bivalent were stable. According to karyotype analysis, the haploid chromosome set was n=24 (24t), and no heteromorphic bivalent was found. The relative length of the longest and shortest bivalent were 5.86 and 1.66, and the length ratio was 3.53, which was much higher than the length ratio of the exact metaphase mitotic karyotype (1.5) and premetaphase endonuclease karyotype (1.75). An idiogram with 447 bands was constructed and the zone of each bivalent was divided, respectively. The detailed description of the landmark system and the band positions were preliminary given. This study aims to provide a theoretical reference for the further research on cytogenetics and the physical map construction of chromosome fine frame of E. malabaricus.