Repeatability of decision-making behaviour in male threespine stickleback Gasterosteus aculeatus: Effects of dummy vs. live stimuli

Individuals select from a number of behaviours when responding to various situations and the decisions they make may affect their fitness. The costs and benefits of these responses vary among individuals causing them to differ even in identical situations. One example of this type of situation is when territorial males encounter both a male and female simultaneously, gene- rating a trade-off that likely leads to individual differences due to differing costs of various actions among males. This situation commonly occurs in threespine stickleback, Gasterosteus aculeatus. However, for selection to act effectively, individuals must behave in a consistent manner and measuring repeatability can aid in understanding how selection may shape such trade-offs. Males of this species exhibit consistent individual differences in their response to dummy males and females but it is unknown if patterns are similar when feedback from the stimuli is present. To assess this, male threespine stickleback were tested with dummy and live male and female conspecifics, presented separately and simultaneously. While the same trends were found regardless of stimulus type, males were more aggressive towards the live conspecifics than to the dummies. Repeatability values were similar within a treatment regardless of whether live or dummy conspecifics were used, suggesting that individuals show the same level of consistency. This study adds to our understanding of consistent individual differences by demonstrating that feedback may not affect responses to conflicting stimuli and that male threespine stickleback respond in a consistent manner to both dummy and live stimuli [Current Zoology 57 (1): 101–108, 2011]

Audience effect is context dependent in Siamese fighting fish, Betta splendens

Investigations of communication networks in animals have focused primarily on determining whether animals extract information from peripheral contests (eavesdropping) or respond to the presence of bystanders (audience effect). The possibility that an animal's response to being watched might be context dependent, however, has been explored in far less detail. This study investigated the influence of two contexts, exposure to audiences of different sexes and presence or absence of a nest, on the aggressive behavior of interacting male Siamese fighting fish, Betta splendens. Males interacted in the presence (male, female) or absence of an audience in three different nest conditions (0, 1, or 2 nests). Audience sex and territorial status influenced aggressive behavior in the interacting males, but a strong audience � nest interaction also was uncovered. Males were more aggressive when neither male had a nest and a male audience was present than when a female or no audience was present. Males also were more aggressive when only one male had a nest and a male audience was present than when a female or no audience was present. When both males had nests and a male audience was present, however, males were less aggressive than when only one male or neither male had a nest. In sum, aggressive behavior was influenced by the interaction between audience and nest; neither nest nor audience alone was sufficient to explain the results. Male Siamese fighting fish alter their behavior based on both external cues, the sex of the audience, and internal cues, reproductive state and resource possession. Our results emphasize the importance of considering aspects of an animal's environment when examining audience effects and communication networks in general. Copyright 2005.aggression; audience effects; Betta splendens; communication networks

Exposure to the ultraviolet filter benzophenone-3 (BP3) interferes with social behaviour in male Siamese fighting fish

© 2019 The Association for the Study of Animal Behaviour Oxybenzones like benzophenone-3 (BP3) are ultraviolet (UV) filters widely used in personal care products such as sunscreens. BP3 is currently receiving a great deal of attention because many of its properties, including high water solubility and potential to bioaccumulate, enable it to have damaging effects on aquatic ecosystems. One of these effects, the induction of coral bleaching, has led Hawaii to ban all sunscreens containing BP3. BP3 also appears to have endocrine-disrupting properties and has been found to affect animal physiology. However, behavioural consequences of BP3 exposure have yet to be thoroughly characterized. In the present study, we investigated the effects of BP3 on boldness, courtship and aggression in male Siamese fighting fish, Betta splendens, as little is known about the effects that BP3 has on fish social behaviour. To accomplish this, we assigned males to a treatment group (control, low, medium or high BP3 concentration) and completed individual (empty tank, novel environment and shoal) and social (courtship and aggression) behavioural assays before and after a 28-day exposure period. BP3 influenced the expression of social behaviours, with individual boldness generally unaffected. Changes in shoaling occurred regardless of BP3 concentration, while BP3-associated decreases in courtship and aggression were concentration dependent. Abnormal social behaviour may impede successful mating and alter territorial dynamics, with potentially heightened effects in species already experiencing other anthropogenic stressors

Exposure to the ultraviolet filter benzophenone-3 (BP3) interferes with social behaviour in male Siamese fighting fish

© 2019 The Association for the Study of Animal Behaviour Oxybenzones like benzophenone-3 (BP3) are ultraviolet (UV) filters widely used in personal care products such as sunscreens. BP3 is currently receiving a great deal of attention because many of its properties, including high water solubility and potential to bioaccumulate, enable it to have damaging effects on aquatic ecosystems. One of these effects, the induction of coral bleaching, has led Hawaii to ban all sunscreens containing BP3. BP3 also appears to have endocrine-disrupting properties and has been found to affect animal physiology. However, behavioural consequences of BP3 exposure have yet to be thoroughly characterized. In the present study, we investigated the effects of BP3 on boldness, courtship and aggression in male Siamese fighting fish, Betta splendens, as little is known about the effects that BP3 has on fish social behaviour. To accomplish this, we assigned males to a treatment group (control, low, medium or high BP3 concentration) and completed individual (empty tank, novel environment and shoal) and social (courtship and aggression) behavioural assays before and after a 28-day exposure period. BP3 influenced the expression of social behaviours, with individual boldness generally unaffected. Changes in shoaling occurred regardless of BP3 concentration, while BP3-associated decreases in courtship and aggression were concentration dependent. Abnormal social behaviour may impede successful mating and alter territorial dynamics, with potentially heightened effects in species already experiencing other anthropogenic stressors