Colour preference in juvenile European lobster (Homarus gammarus)

Lobsters are high-value marine-fished species, and re-stocking efforts are essential for replenishing depleted wild populations and ensuring the longevity of these valuable marine species. The need for stock enhancement and hatcheries for aquaculture is vital to reduce the strain on wild populations. Therefore, environmental colours should be acknowledged when rearing lobsters in terms of behaviour, growth, movement, and survival. However, the behavioural effects the surrounding colour poses are virtually unknown. To better understand this behaviour, the movement of juvenile European lobsters (Homarus gammarus) was analysed through videos in two sub-trials. Lobsters were acclimated to custom-made alternating colour chambers, allowing for colour preferences based on individual movement. Sub-trial one alternated between black, red, blue, green, white, and yellow. The study identified that there was a significant preference for black (1 hour and 51 minutes) and red (1 hour and 33 minutes), indicating a potential underlying benefit for juvenile H. gammarus development. Despite this, little is known about the overall association of colour and lobster perception. A better understanding of environmental colour preference may guide the construction of aquaculture units to suit colour preference and enhance acclimation into newly released environments. This experiment aims to determine the preferred colours of stage four juvenile H. gammarus in a controlled laboratory setting and inspire further research to explore this unfamiliar field.