Prawn colours still in the dark….not to mention moon cycle effect or how tidal fluctuations also could play a role…

https://www.frontiersin.org/articles/10.3389/fmars.2021.750384/full

For shrimp larvae culture full 24/7 works well – supports algal growth

Some grow out juvenile to market studies have shown 24/7 light increases chromatophores.

Some studies show colour can be changed with feed additive, tank colour, substrate.

Lots of R&D still possible…but for intensification it is way down the list…

Want dark prawn – use sunlight or, indoor, metal halide lamps if in clear water culture…..

Astaxanthin accumulation not for growth promotion but for protection against intense light.

Effects of different light sources and illumination methods on growth and body color of shrimp Litopenaeus vannamei