Physical length of metaphase chromosomes in Collichthys lucidus

In order to support the development of genomics and cytogenetics of Collichthys lucidus, in the present study, the genome size of C. lucidus was determined by using flow cytometry, and the relative length, the relative area and the integrated optical density (IOD) of 24 pairs of chromosomes were determined using PI staining and microscopic image analysis software, and the physical length of chromosomes was estimated based on the values of IOD. The results showed that male and female's genome sizes were respectively estimated at (786.52±1.95) Mb and (802.91±2.19) Mb. Female genome was significantly larger than male genome (by about 16.39 Mb). The genome of female comprised 24 pairs of telocentric chromosomes, the karyotype formula is 2n=48=48t, NF=48, with the physical length ranging from (22.17±0.72) Mb to (46.30±1.06) Mb. The genome of male comprised 46 telocentric chromosomes and one metacentric chromosome, the karyotype formula is 2n=47=46t+1m, NF=48. The male specific metacentric chromosome was Y chromosome, with an estimated physical length of (62.95±2.89) Mb. Physical lengths of chromosomes are correlated linearly with the relative area and the relative lengths. In conclusion, new parameters of chromosomes present in this paper will facilitate to chromosome identification and pairing of C. lucidus, which will serve as reference data for the assembly of the Y chromosome and the evolution of chromosome in Sciaenidae.