In recent years, evidence for interindividual variation in ''personality'' within animal populations has been accumulating. Personality is defined as consistency in an individual's behavioral responses over time and/or across situations. One personality trait that has potentially far-reaching implications for behavioral ecology, and may provide insight into the mechanisms by which consistent behavioral correlations arise, is that of boldness. Boldness is defined as the tendency of an individual to take risks and be exploratory in novel contexts. Using the framework of behavioral syndromes, we tested for individual differences in boldness in the laboratory among field-caught juvenile bluegill sunfish (Lepomis macrochirus) within and across the contexts of exploratory behavior, activity, and risk taking (e.g., antipredator) behavior. After such testing, individuals were tagged and returned to their lake of origin as part of a mark-recapture study testing for the repeatability of individual differences in boldness. Here, we report strong and consistent individual differences in boldness within and across all 3 behavioral contexts. Additionally, we observed that at least some boldness behaviors were repeatable after a 1-3 month recapture period. This study provides novel evidence for a boldness syndrome in sunfish, as well as insight into how behavioral types (e.g., shy/bold) may evolve and be maintained in natural populations.

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Size-selective harvesting associated with commercial and recreational fishing practices has been shown to alter life history traits through a phenomenon known as fishing-induced evolution. This phenomenon may be a result of selection pathways targeting life-history traits directly or indirectly through correlations with behavioral traits. Here, we report on the relationship between individual differences in behavior and capture technique (beach seining versus angling) in wild-caught juvenile bluegill sunfish ( Lepomis macrochirus ). Both fish caught by using a seine net (seined) and fish caught by using a lure (angled) were individually tested under standardized laboratory conditions for their boldness, water-column use, and general activity. Observed inter-individual differences in boldness were strongly correlated with method of capture in the wild. Fish caught by angling were more timid and had fewer ectoparasites than fish caught using a seine net. However, this relationship did not carry over to an experiment in a large outdoor pool with seine-caught, individually tagged wild fish, where bolder individuals were more likely to be angled in open water away from refuges than more timid individuals, based on their previously assessed boldness scores. Our study is both novel and important, as it describes the relationship between capture technique and boldness in a natural population and underscores the potential risk of sampling biases associated with method of animal capture for behavioral, population, and conservation biologists.

The istiophorid family of billfishes is characterized by an extended rostrum or 'bill'. While various functions (e.g. foraging and hydrodynamic benefits) have been proposed for this structure, until now no study has directly investigated the mechanisms by which billfishes use their rostrum to feed on prey. Here, we present the first unequivocal evidence of how the bill is used by Atlantic sailfish (Istiophorus albicans) to attack schooling sardines in the open ocean. Using high-speed video-analysis, we show that (i) sailfish manage to insert their bill into sardine schools without eliciting an evasive response and (ii) subsequently use their bill to either tap on individual prey targets or to slash through the school with powerful lateral motions characterized by one of the highest accelerations ever recorded in an aquatic vertebrate. Our results demonstrate that the combination of stealth and rapid motion make the sailfish bill an extremely effective feeding adaptation for capturing schooling prey.