types of betta siamese fighting fishTo screen the “elephant ear” locus, a genome wide FST scan was performed between elephant ear mutants and the last resequenced samples, 9 and 28 fish respectively, using 30 kb window size with a step of 15 kb. Variants within and flanking this locus were retrieved and analyzed to refine the haplotypes. Fixed or nearly fixed editions were annotated and protein coding genes within this locus were individually analyzed by literature mining. Genes linked to fin advancement and regeneration were kept for expression analysis using real time reverse transcription PCR RT PCR to determine candidate genes. In order to easily differentiate among genotypes, we built indel markers for instant PCR assays for double tail and albino traits. The shortest genomic region as a result of organization mapping was used for marker screening.