Fish genomes: Sequencing trends, taxonomy and influence of taxonomy on genome attributes

594 fish genomes have been sequenced in past two decades, this represents 1.85% of the total reported fish species (32,000). Despite this no study represents the trends and only some studies have delved into how the genome size (GS) of the genomes are shaped by species taxonomy. However, all these studies have used data obtained by traditional cytometric methods and also have largely disregarded other genome attributes namely GC, number of chromosomes (CR), number of genes (GE), and protein count (PC). The present study used the most current data on genome attributes of fishes as generated by the whole genome sequencing projects to understand the trends, effect of taxonomy on the genome attributes (GS, GC, CR, GE, and PC) and the interrelation of genome attributes. The trends states that maximum number of fish genomes were sequenced in year 2020, order Cichliformes represents the highest number of published genomes, Illumina is the most used technology for sequencing fish genomes, etc. Our analyses exhibit some concrete trends for fishes as a whole and indicated a strong selection for smaller genomes among all vertebrates and a strong effect of taxonomy on all genome attributes. It also provides clear insights that the fish GS is significantly different from birds, amphibians, reptiles, mammals and insects while the GC only varied from insects. An inverse relation was observed between the GS and GC, and a direct relation was observed between the GS and CR, GE and PC. The results also signify that the per MB value of all the genome attributes decline with increasing GS.