Effect of different amount of food and female resource on competitive strategy and agonistic behavior of swimming crab (Portunus trituberculatus)

Feeding strategy changes boldness and agonistic behaviour in the swimming crab ( Portunus trituberculatus )

“…One of the individuals was randomly selected to be marked (painted) with a white dot (Liquitex HB, Liquitex Artist Materials) on the top of its carapace for distinction and to facilitate observation during the fighting. In this experiment, food is the contest resource reference to previous studies (Zhu, Wang, et al, 2021), and the same amount of food extract (clam muscle homogenized in seawater) was slowly injected into the middle of each arena as the separating board was raised while infrared cameras recorded the behaviours for 45 min. Twenty‐four fights were conducted in each fight treatment group.…”

“…However, due to the aggression of crustaceans, the low survival rate caused by fighting severely restricts the improvement of yield and the further development of the industry. In order to reduce fighting between individuals, researchers have carried out considerable work, investigating topics such as the separation breeding of males and females, the laying of shelter or the use of land‐based factory breeding methods (Guo et al, 1997; He et al, 2017; Zhu, Wang, et al, 2021). However, research to date has mainly focussed on measures to prevent fighting and has seldom explored the internal behaviour and physiological basis of fighting from the perspective of the agonistic behaviour of crustaceans.…”

“…The swimming crab P. trituberculatus is an aggressive crustacean (Liang et al, 2020), and intraspecies cannibalism often occurs when they compete for access to essential resources such as food or shelter (Liu et al, 2017; Zhu, Lu, et al, 2021; Zhu, Wang, et al, 2021). Feeding management is the key to the survival and growth of cultured individuals.…”

The Effect of Intruder Density on Territoriality and Dominance in Male Swimming Crab (Portunus trituberculatus)

“…One bout is defined as the process of crabs moving to, contacting, and retreating. The crab that caused its opponent to retreat repeatedly in a bout was considered the winner [29]. The crab gained a "dominance sign" when it caused its opponent to retreat in the last bout [20].…”

“…It is vulnerable to intense fighting and cannibalism due to its aggressive nature [26,27], resulting in high mortality and fluctuations in the population [3]. Previous studies have found that cannibalism can attributed to lack of food, crowded space, and stresses generated by an unhealthy environment [28,29]. Territory may have potential in regulating cannibalism of territorial crustaceans since it has been indicated to affect competition [25].…”