Dye Submersion
Submersion into a color bath (Nile blue sulphate, Alizarin, Methylen blue, Trypan blue, Gentiana violet, Janus green, Litium-carmin, Neutral red and Bismarck brown) can produce temporary external colorization in some species. Depending on species, fish may require color bath submersion for several hours and produce recognizable marking that can last from a couple of days to several weeks.
Advantages:
- Inexpensive and can mark entire group simultaneously
- Marks do not effect fish growth or behavior
- Marks can be applied to a wide size range of fish and on many species
Disadvantages:
- Submersion dye marking is for groups only, not individuals
- In most cases, researchers must recover the marked fish themselves in order to collect data
- Marks may deteriorate with time and cause recognition errors