Background Research on human infants, mammals, birds and fish has demonstrated that rudimentary numerical abilities pre-date the evolution of language. Yet there is controversy as to whether animals represent numbers mentally or rather base their judgments non-numerical perceptual variables co-vary with numerosity. To date, mental representation number been convincingly documented only for a few mammals. Methodology/Principal Findings Here we used training procedure investigate mosquitofish...

Escape performance is fundamental for survival in fish and most other animals. While previous work has shown that both intrinsic (e.g. size, shape) extrinsic temperature, hypoxia) factors can affect escape performance, the possibility behavioural asymmetry may timing locomotor startled largely unexplored. Numerous studies have found a relationship between brain lateralization several cognitive tasks. Here, we tested hypothesis teleost, shiner perch Cymatogaster aggregata . responses were...

Laboratory and field studies have documented better cognitive performance associated with marked hemispheric specialization in organisms as diverse chimpanzees, domestic chicks topminnows. While providing an evolutionary explanation for the emergence of cerebral lateralization, this evidence represents a paradox because large proportion non-lateralized (NL) individuals is commonly observed animal populations. Hemispheric often determines left-right differences perceiving responding to...

Motion illusion refers to a perception of motion that is absent or different in the physical stimulus. These illusions are powerful non-invasive tool for understanding neurobiology vision because they tell us, indirectly, how we process motion. There general agreement ascribing higher-level processing visual cortex, but debate remains about exact role eye movements and cortical networks triggering it. Surprisingly, there have been no studies investigating global illusory evoked by static...

The occurrence of functional left–right cerebral asymmetries has been documented in a wide range animals, suggesting that the lateralization cognitive functions enjoys some kind selective advantage over bilateral control same functions. Here, we compared schooling performance fishes with high or low degree lateralization, which were obtained through breeding. Schools lateralized moving novel environment showed significantly more cohesion and coordination than schools non-lateralized (NL)...

It has been hypothesized that cerebral lateralization can significantly enhance cognition and this was one of the primary selective forces shaping its wide-spread evolution amongst vertebrate taxa. Here we tested hypothesis by examining link between numerical discrimination. Guppies, Poecilia reticulata, were sorted into left, right non-lateralized groups using a standard mirror test their discrimination abilities in both natural shoal choice abstract contexts. Our results show strongly...

Abstract For a diversity of species, differences in sexual and parental roles, along with body morphology, often result males females having different diets, distinct predators even patterns habitat use. As consequence, the two sexes face environmental challenges selection may favour evolution sex cognition. We tested this prediction guppy ( Poecilia reticulata ). Under perceived hazard, individual guppies join larger available social group, behaviour that is thought to minimise predation...

Animals engaged in a complex task are often unable to allocate enough attention second concurrent task. We tested the hypothesis that cerebral lateralization is advantageous because it enables separate and parallel information processing allows for more efficient performance of cognitive tasks. Lateralized nonlateralized (NL) female Girardinus falcatus, obtained through selective breeding experiment, were compared situation requiring sharing between two simultaneous tasks, retrieving food...

The novel object recognition (NOR) test is a widely-used paradigm to study learning and memory in rodents. NOR performance typically measured as the preference interact with over familiar based on spontaneous exploratory behaviour. In rats mice, females usually have greater ability than males. now available for large number of species, including fish, but sex differences not been properly tested outside We compared male female guppies (Poecilia reticulata) whether exist also fish. focused...

Pea plants depend on external structures to reach the strongest light source. To do this, they need perceive a potential support and flexibly adapt movement of their motile organs (e.g. tendrils). In natural environments, there are several above- belowground elements that could impede complete perception supports. such instances, may be required perform sort perceptual "completion" establish unified percept. We tested whether pea capable performing completion by investigating ascent...

Abstract Male sexual harassment has been demonstrated to result in high costs for females. mosquitofish are amongst the most ardent animal kingdom and can halve female foraging efficiency. Female have found vary their shoaling behaviour when harassed by a male, approaching other males promote male–male interactions or reducing distance another dilute male disturbance. The present study tested two predictions about counterstrategies. As dilution effect increases with group size, was expected...