The role of different sensory organs in the feeding behavior of Chinese mitten crab (Eriocheir sinensis)

Abstract

Because of the complex aquatic environment, it is difficult to research the behaviors of crustaceans. As we know, the feeding behavior of Chinese mitten crab (Eriocheir sinensis) has rarely been reported so far, although the crabs have high commercial value in China. Understanding its feeding behavior is helpful for supporting the development of aquaculture. In this study, we first observed the feeding preferences of E. sinensis regarding a series of diets. The results showed that E. sinensis has a significant preference for the muscle of Bellamy aquadrata (P < 0.05). However, the crab was not picky about the meat of several different aquatic animals after starvation, except for pellet feed. We then used a method of physical ablation of the setae to determine the functions of several sensory organs in detecting food sources. The feeding reaction time significantly increased after the ablation of the antennule and leg setae (P < 0.05), and the feeding reaction time increased the most in the antennule group compared with the control group and the mouthpart group. In addition, a real and fake food test was designed to further explore the role of the mouthparts in feeding behavior. We found that the time to manipulate the real and fake food was significantly increased after ablation of the mouthpart setae (P < 0.05). Finally, the food color preference of E. sinensis was observed by using several foods dyed in different colors. However, the crabs performed no food color preference in this study. In conclusion, the different chemical sensory organs play different roles in the feeding behavior of E. sinensis. According to the results, the ablation of the antennule and leg setae impairs the crab's ability to explore food and reduces the food intake. Moreover, ablation of the mouthpart setae affected the crabs' judgment of food quality and prolonged the time of food manipulation. However, E. sinensis exhibited a weak color preference. This study provided insights into the more attractive food of E. sinensis; at the same time, it also determined the importance of chemical information for animals and the role of different chemical sensory organs, laying a foundation for the study of food attractants.