Effect of different light intensity in the growth and survival of Hippocampus kuda (yellow seahorse) under laboratory conditions

Seahorses are charismatic fishes that are a focus for marine conservation efforts. Among many species of seahorses, the yellow seahorse, Hippocampus kuda, are subject to growing market demand. The study aims to identify the suitable light intensity for seahorses under small-scale laboratory set-up, to come up with recommendations for effective seahorse rearing. This investigation examined the effect of different light intensities (500 lx, 1000 lx, 1500 lx) on the growth and survival of male and female seahorses H. kuda. Results show an insignificant difference in the average weight and standard length of H. kuda as a measure of growth between the different light intensities with p=0.723 for the weight and p= 0.602 for the standard length respectively. However, it was observed that darker environment showed poor prey contrast and therefore increased the efforts in feed intake. For the comparison between male and female H. kuda, there is a significant difference in the growth between male and female H. kuda in terms of the average length across different light intensities with p= 0.001 wherein, male species of H. kuda exhibited a greater rate of growth in terms of weight and length compared to the female. Moreover, males have aggressive behaviors such as tail wrestling and snapping of snout. Results demonstrated that the presence of light can improve the growth rate of male H. kuda species.