Effects of Different Habitat Space on Growth Performance and Nutritional Composition of Swimming Crabs (Portunus trituberculatus)

Abstract

Habitat space is crucial for animals. This experiment explored the effect of four different farming acreages (0.5 m2, 1 m2, 10 m2, and 100 m2) on survival rate, growth performance, and muscle nutrition composition of swimming crabs (Portunus trituberculatus) at the farming density of 2 ind/m2. The results showed that the survival rate of the crabs that live in the 10 m2 group and live in 0.5 m2 alone had the highest survival rate of 20.50% and 20%, better than the 1 m2 group and the 100 m2 group with the lowest of 12.00% and 13% ( $P<0.05$ ). There was no significant difference between final body weight and final carapace width among the 4 groups ( $P>0.05$ ). The crude lipid content was the highest in 1 m2, which was significantly higher than in 0.5 m2 ( $P<0.05$ ). The crude protein content in the 1 m2 and 10 m2 groups was significantly higher than that in the 0.5 m2 and 100 m2 groups ( $P<0.05$ ). The results of the three conventional nutrients showed that there was no positive correlation between the muscle conventional nutrients and the farming area. The polyunsaturated fatty acid part of the 100 m2 and 10 m2 group was significantly different from the 1 m2 and 0.5 m2 groups ( $P<0.05$ ). The results show that farming crab alone is not better than together, and a small aquaculture acreage helps to improve the muscle nutrition composition of the swimming crabs, while a large aquaculture acreage is more conducive to balance the development of nutrition. Overall, 10 m2 of habitat space was more economically feasible in practice.