A New Method of Aquatic Animal Personality Analysis Based on Machine Learning (PAML): Taking Swimming Crab Portunus trituberculatus as an Example

Abstract

Personality differences are an important part of animal behavior research and a potential factor affecting the physiochemical response of animals to stimuli. Therefore, accurate classification of personality has an impact on animal experiment research that cannot be ignored. However, no completely objective methods have been noticed hitherto to be employed in aquatic animal personality studies. To address this issue, we established a personality analysis method based on machine learning (PAML) to avoid the influence of subjective factors. Then we analyzed the personality changes of swimming crab Portunus trituberculatus exposed to external stimuli i.e., food deprivation. Results showed that the high-accuracy PAML method could provide a comprehensive understanding of crab personality classification. Based on PAML, the personality of P. trituberculatus was detected to change dynamically under stress. After analyzing three typical personality characteristics: boldness, activity, and hesitancy, we found that the stability of boldness was the strongest, which is the best single candidate for personality evaluation, while the activity changed greatly under stress. This study confirms that animal personality changes dynamically with external factors. Based on PAML, we can not only avoid subjective factors and improve classification accuracy, but also quantitatively trace the dynamic influence of external factors on aquatic animal personality.

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

“…It indicates that all of the crabs have adapted to the experimental environment, so we start experiment. We used the video capture system (Figure 1a) to record the boldness behaviour of the crabs, the system consisted of a round aquarium (diameter = 60 cm, height = 50cm), a camera (HIKVISION, DS-2CD864, infrared wavelength = 850 nm), a monitor (PHILLIP, Yang et al,2020), and agonistic behaviour was measured after classification. bold individuals).…”

Quantifying the Effects of Diver Interactions on Manta Ray Behavior at Their Aggregation Sites

“…Recent studies suggest personalities could affect the response of certain individuals, even in aquatic animals, and that these "bolder" individuals could have an effect over the evolution of their species (Wolf and Weissing, 2012). The nature of our data makes it impossible to apply the required experimental design for these analysis (Yang et al, 2020).…”

The Developmental Plasticity of Boldness and Aggressiveness in Juvenile and Adult Swimming Crab (Portunus trituberculatus)

“…Thus, the time crabs left the shelter for the first time was inversely proportional to boldness (Cote et al, 2010;Brodin and Drotz, 2014). According to the k-means cluster analysis (Yang et al, 2020), boldness of both juvenile and adult crabs was divided into three levels: bold, middle, and shy.…”

“…Aggressiveness was measured based on the number of aggressive interactions. According to the k-means cluster analysis (Yang et al, 2020), aggressiveness was divided into two levels: aggressiveness (the most aggressive males were identified as those with the highest number of aggressive interactions) and non-aggressiveness (the least aggressive males had the least number of aggressive interactions).…”

“…Each individual was studied only once for their behaviors. Individuals with similar personality were classified into the same group through k-means cluster analysis (Yang et al, 2020). Thereafter, individual differences in personality between group levels in juvenile and adult crabs were assessed, and behavioral correlation was measured and analyzed to estimate whether the personality of P. trituberculatus males is consistent with developmental plasticity.…”