Abstract:
The individual difference of behavior in fish species is defined as personality. It has been found that fish exhibit personality which might remain to some extend when join a group. However, the ecological relevance of withholding of personality, i.e. individuality during shoaling has not been investigated. To study the ecological relevance of individuality and traditionally measured personality traits in a group living fish species, we first measured standard metabolic rate (for estimation of maintenance metabolism, SMR), personality traits of activity, exploration, boldness and sociability of pale chub (
Zacco platypus) of the fish that were grouped randomly into shoal of six individuals. SMR, feeding rate and daily energy expenditure (DEE) had no relationship with any personality variables. The lack of correlation between personality and feeding rate may be due to the high food abundance of pale chub in the wild, and the personality is not reflected in the competition for food. The relationship between personality and metabolism was not found. The DEE was positively correlated with percent time moving, average swimming speed and the feeding rate within the shoal. In addition, the DEE was also positively correlated with the distance to centroid. The results suggest that, it may be more ecologically meaningful to investigate their personality traits within the shoal using group living wild fish.