Half Black exists in two versions. X-Y linked and X-linked . First one readily jumps between X and Y – black is not so expressive. Second one only X-linked – black is much more expressive. Of course whole phenotype look depends on other genes.Very often with Half Black is linked so called Asian Neon gene characterised by white dorsal fin and higher guanine production on peduncle and around dorsal – creating a shiny look to a fish. Of course this gene is also influenced by others in genotype so dorsal won’t always be white. How much phenotypic variation depends on other genes can be seen on example picture of sibling brothers:
Bolesław Gaweł fish:
Grzegorz Prusinowski examples:
It is fun gene to work with. Especially with coexpression with other genes. Below examples with and without autosomal red. Also linked with half black gene is so called Asian Neon gene (white dorsal and shine on parts of peduncle and around dorsal fin).
Below examples without autosomal red. Easly seen how much phenotypic appearance depends on base body colors genetics.
Magenta and halfblacks could give astonishing effects. Fish from Bolesław Gaweł: