Effect of broodstock origin, background and substrate color on skin coloration of three-spotted seahorses Hippocampus trimaculatus Leach, 1814

Abstract: Seahorse performing attractive skin color under sensitive environmental conditions has been of favor for aquarists and aquaculturists. This study investigated the skin coloration and fading process, and the effects of broodstock, background and substrate color on the skin coloration of the three-spotted seahorse Hippocampus trimaculatus Leach, 1814. The formation of skin coloration was in the sequence of abdomen, tail, back and head, respectively. Seahorse color changed from black to yellow within 26.41±6.28s in response to sudden tactile stimuli, and then faded to the original black color within 259±147.5s. Skin coloration negatively correlated with seahorse body size: the smaller the seahorse, the easier seahorse changed skin color. Compared among six background color treatments (white, red, brown, yellow, blue and clear, respectively), the skin coloration rate (% changed from black to yellow) was the highest in the blue background (86.4±11.6%, P <0.001). Seahorses derived from three broodstock origin (A, B and C) had different skin coloration rates of 44.2, 41.6 and 17.1%, respectively (P =0.012). When cultured with four different substrate colors (yellow, green, red and the mixture, respectively) for 5days, 77.8% of the seahorses with the yellow substrate changed their skin color to yellow (P =0.007), and all seahorses with the red became yellow or yellow-black skin. As a novelty, this is the first report of the instantaneous skin color change in seahorses, and this study will be of interest for the behavior study and ornamental aquaculture of H. trimaculatus. [Copyright &y& Elsevier]