Submissive behavior is affected by territory structure in a social fish.

Group living may engender conflict over food, reproduction, or other resources and individuals must be able to manage conflict for social groups to persist. Submission signals are an adaptation for establishing and maintaining social hierarchy position, allowing a subordinate individual to avoid protracted and costly aggressive interactions with dominant individuals. In the daffodil cichlid fish (), subordinates may use submission signals to resolve conflicts with dominant individuals and maintain their social status within the group.

Submissive behaviour is affected by group size in a social fish.

For social groups to form and be stable over time, animals must develop strategies to cope with conflict among group members. Animals may behave submissively either by fleeing from an aggressor, or by signalling submission. The use of these two submissive responses may vary depending on the social and ecological context.

Nutraceutical supplementation increases mobility in aged captive non-domesticated felids.

Background: Musculoskeletal diseases (MSDs) are an increasing issue as the lifespan of captive animals increases. Extracts of green-lipped mussels have been linked to alleviation of MSDs in domestic carnivores. Understanding their efficacy in non-domestic felids could provide another tool to improve the welfare of aged individuals in collections.

Heart and brain: Change in cardiac entropy is related to lateralised visual inspection in horses.

Cerebral lateralisation is the tendency for an individual to preferentially use one side of their brain and is apparent in the biased use of paired sensory organs. Horses vary in eye use when viewing a novel stimulus which may be due to different physiological reactions. To understand the interplay between physiology and lateralisation, we presented a novel object (an inflated balloon) to 20 horses while electrocardiogram traces were collected.

Fellowship of the fin: Fish empathy and oxytocin.

Zebrafish exhibit fear contagion, a basic form of empathy, and when observing social fellows that have been exposed to predation cues, will themselves exhibit similar distress behaviours. As in mammals, the nonapeptide hormone oxytocin is essential for this empathic response, and homologous areas of the brain are involved, suggesting that the mechanistic basis of empathy may be conserved among vertebrates.

Horses show individual level lateralisation when inspecting an unfamiliar and unexpected stimulus.

Animals must attend to a diverse array of stimuli in their environments. The emotional valence and salience of a stimulus can affect how this information is processed in the brain. Many species preferentially attend to negatively valent stimuli using the sensory organs on the left side of their body and hence the right hemisphere of their brain.

Head up displays are a submission signal in the group-living daffodil cichlid.

Dominance hierarchies can reduce conflict within social groups and agonistic signals can help to establish and maintain these hierarchies. Behaviours produced by subordinates in response to aggression are often assumed to function as signals of submission, however, these behaviours may serve other purposes, for example, defence or escape. For a behaviour to act as a submission signal, the receiver must respond by reducing their likelihood of further aggression towards the signaller.

Consistency and flexibility in solving spatial tasks: different horses show different cognitive styles.

Individual animals vary in their behaviour and reactions to novel situations. These differences may extend to differences in cognition among individuals. We tested twenty-six horses for their ability to detour around symmetric and asymmetric obstacles.

Isotocin neuronal phenotypes differ among social systems in cichlid fishes.

Social living has evolved numerous times across a diverse array of animal taxa. An open question is how the transition to a social lifestyle has shaped, and been shaped by, the underlying neurohormonal machinery of social behaviour. The nonapeptide neurohormones, implicated in the regulation of social behaviours, are prime candidates for the neuroendocrine substrates of social evolution.

Social motivation and conflict resolution tactics as potential building blocks of sociality in cichlid fishes.

Even closely related and ecologically similar cichlid species of Lake Tanganyika exhibit an impressive diversity of social systems, and therefore these fishes offer an excellent opportunity to examine the evolution of social behaviour. Sophisticated social relationships are thought to have evolved via a building block design where more fundamental social behaviours and cognitive processes have been combined, incrementally modified, and elaborated over time. Here, we studied two of these putative social building blocks in two closely related species of cichlids: Neolamprologus pulcher, a group-living species, and Telmatochromis temporalis, a non-grouping species.

Within-group relatedness is correlated with colony-level social structure and reproductive sharing in a social fish.

In group-living species, the degree of relatedness among group members often governs the extent of reproductive sharing, cooperation and conflict within a group. Kinship among group members can be shaped by the presence and location of neighbouring groups, as these provide dispersal or mating opportunities that can dilute kinship among current group members. Here, we assessed how within-group relatedness varies with the density and position of neighbouring social groups in Neolamprologus pulcher, a colonial and group-living cichlid fish.

Social cichlid fish change behaviour in response to a visual predator stimulus, but not the odour of damaged conspecifics.

Predation is one of the primary drivers of fitness for prey species. Therefore, there should be strong selection for accurate assessment of predation risk, and whenever possible, individuals should use all available information to fine-tune their response to the current threat of predation. Here, we used a controlled laboratory experiment to assess the responses of individual Neolamprologus pulcher, a social cichlid fish, to a live predator stimulus, to the odour of damaged conspecifics, or to both indicators of predation risk combined.

Demasculinization of male guppies increases resistance to a common and harmful ectoparasite.

Parasites are detrimental to host fitness and therefore should strongly select for host defence mechanisms. Yet, hosts vary considerably in their observed parasite loads. One notable source of inter-individual variation in parasitism is host sex.

Reproductive sharing in relation to group and colony-level attributes in a cooperative breeding fish.

The degree to which group members share reproduction is dictated by both within-group (e.g. group size and composition) and between-group(e.

Brain nonapeptide levels are related to social status and affiliative behaviour in a cooperatively breeding cichlid fish.

The mammalian nonapeptide hormones, vasopressin and oxytocin, are known to be potent regulators of social behaviour. Teleost fishes possess vasopressin and oxytocin homologues known as arginine vasotocin (AVT) and isotocin (IT), respectively. The role of these homologous nonapeptides in mediating social behaviour in fishes has received far less attention.

A comparative study of an innate immune response in Lamprologine cichlid fishes.

Social interactions facilitate pathogen transmission and increase virulence. Therefore, species that live in social groups are predicted to suffer a higher pathogen burden, to invest more heavily in immune defence against pathogens, or both. However, there are few empirical tests of whether social species indeed invest more heavily in immune defence than non-social species.

Water pH during early development influences sex ratio and male morph in a West African cichlid fish, Pelvicachromis pulcher.

Environmental sex determination (ESD) is one of the most striking examples of phenotypic plasticity. Individuals from species that exhibit ESD can develop as either males or females depending on the particular environmental conditions they experience during early development. In fish, ESD species often show a relatively subtle effect of environment, resulting in a substantial number of both sexes being produced in both male- and female-biasing conditions, rather than the unisex clutches that are typical of many reptiles.

Probing aggressive motivation during territorial contests in a group-living cichlid fish.

Many animals fight to win resources, repel competitors or establish dominance in a social group. Mutual-assessment of fighting ability, where competitors gather and compare information about their opponent's as well as their own fighting ability has been the dominant theoretical framework for understanding decision-making during fights. However, self-assessment, where each individual has a cost threshold and fights up until that point, may be more common than previously appreciated.

Lateralized behaviour of a non-social cichlid fish (Amatitlania nigrofasciata) in a social and a non-social environment.

Cerebral lateralization, the partitioning of cognitive function preferentially into one hemisphere of the brain, is a trait ubiquitous among vertebrates. Some species exhibit population level lateralization, where the pattern of cerebral lateralization is the same for most members of that species; however, other species show only individual level lateralization, where each member of the species has a unique pattern of lateralized brain function. The pattern of cerebral lateralization within a population and an individual has been shown to differ based on the stimulus being processed.

Variation in asymmetry of the habenular nucleus correlates with behavioural asymmetry in a cichlid fish.

Asymmetries in brain and behaviour have been demonstrated in numerous species representing all major vertebrate taxa, and may be a universal feature of the vertebrate nervous system. While descriptions of lateralization at the behavioural and neuroanatomical level are widespread, examples of correlation between asymmetries in behaviour and neural structures remain relatively scarce. In the past few years, the habenular nucleus has emerged as a potential site for the neural basis of some lateralized behaviours.

Sometimes slower is better: slow-exploring birds are more sensitive to changes in a vocal discrimination task.

Animal personality, defined as consistent individual differences across context and time, has attracted much recent research interest in the study of animal behaviour. More recently, this field has begun to examine how such variation arose and is maintained within populations. The habitat-dependent selection hypothesis, which posits that animals with differing personality types may fare better (i.

Sex differences in the relationship between aggressiveness and the strength of handedness in humans.

Cerebral lateralisation, the partitioning of cognitive functioning into one hemisphere of the brain, was once considered unique to humans; however, recent research in a variety of taxa suggests that lateralisation is an evolutionarily ancient adaptation. Handedness is the most obvious manifestation of cerebral lateralisation in humans. Much of the literature on handedness has focused on the direction, rather than the strength, of this lateralisation.

Lateralization in response to social stimuli in a cooperatively breeding cichlid fish.

Cerebral lateralization, an evolutionarily ancient and widespread phenomenon among vertebrates, is thought to bestow cognitive advantages. The advantages of lateralization at the individual-level do not necessarily require that the entire population share the same pattern of lateralization. In fact, directional bias in lateralization may lead to behavioural predictability and enhanced predator success or prey evasion.

Exploration of a novel space is associated with individual differences in learning speed in black-capped chickadees, Poecile atricapillus.

Individual variation in exploratory behaviour has been demonstrated in a diverse array of animal species. Understanding the evolutionary antecedents and ecological consequences of this variation is an active research area within animal behaviour. Here we investigate whether different exploration styles exhibited by black-capped chickadees (Poecile atricapillus) in a novel environment are related to how quickly these birds learn an acoustic discrimination task.