Visual adaptations to dim-light conditions in teleost fishes

The goal was to investigate the visual system of the deep-sea pearlsides (Maurolicus spp.), which behaves differently to other mesopelagic fishes in that they are active at the surface only during dusk and dawn. Using a multidisciplinary approach including RNAseq, histology, microscopy, immuno-histochemistry, in-situ hybridization and in-vitro expression assays we show that the pearlside use that pearlsides have evolved an unconventional visual system to optimize visual performance in twilight conditions.