Effect of rearing temperature on the body shape of Angel fish (Pterophyllum scalare Lichtenstein, 1823) during early development using geometric morphometric method

Temperature as an environmental factor, play important role in fish life. Angel fish (Pterophyllum scalare) is one of the most popular fish species that its production has developed in the ornemental fish industery and there is little information about the effect of rearing temprature in the aquarium. Hence, this study was carried out to investigate the effect of temperature on its body shape during the early development using geometric morphometric approach. In total sixty newly hatched larvae reared in two temperature treatments (16 and 28oC) for a period of one month. Then the left side of the specimens were photographed and fourteen landmark points defined and digitised on 2D picture using tpsDig2 sotware to extract body shape data.The extracted data after GPA analysis, were analyzed using DFA and p value of permutation test with ten thousand repetitions. The results revealed significant different between body shape of two treatments showing higher body depth and fusiform body shape, lower caudal peduncle depth and a longer head length in higher temperature. The results confirmed that temperature as important environmental parameter impacts and regulate the body shape of angel fish during early oncogenic development.