The evolution of teleost coloration is strongly linked with the fish-specific genome duplication (FSGD). Sepiapterin reductase (Spr) is commonly required in pteridine pigment synthesis and two paralogs are found in teleosts. However. the functions of spra and sprb in pigmentation have not been completely elucidated. https://www.perfumetank.com/product-category/floor-care-concrete/