Adaptive background colour responses in palaemonid shrimp: a study on Cuapetes purushothamani

ABSTRACT The present study examined how background colours influence the body colouration of Cuapetes purushothamani, a newly discovered palaemonid shrimp from Lakshadweep, India. Shrimps were placed in tanks with black, blue, green, and white backgrounds (10 per colour, two replicates of 5 each) without substrate. Photographs were taken at the start and after 50 days to analyse colour changes using RGB values (Red, Green, Blue) from the cheliped, eye stalk, first abdominal somite, and telson via ImageJ software. Initially, RGB values varied due to different collection environments. After the experiment, black backgrounds significantly affected both sexes (p < 0.05), while blue influenced males but not females first abdominal somite. Telson colour differed between sexes in the green background (p < 0.05), while all parts except the female telson differed in the white background (p < 0.05). Shrimps darkened in black and blue tanks for camouflage, while white and green backgrounds led to the abdomen and telson brightening. These findings highlight C. purushothamani’s ability to adjust colouration for survival, offering insights into its behavioural ecology, camouflage strategies, and applications in biodiversity conservation and aquaculture.