Zebrafish (Danio rerio) are rapidly gaining popularity in translational neuroscience and behavioral research. Physiological similarity to mammals, ease of genetic manipulations, sensitivity to pharmacological and genetic factors, robust behavior, low cost, and potential for high-throughput screening contribute to the growing utility of zebrafish models in this field. Understanding zebrafish behavioral phenotypes provides important insights into neural pathways, physiological biomarkers, and genetic underpinnings of normal and pathological brain function. Novel zebrafish paradigms continue to appear with an encouraging pace, thus necessitating a consistent terminology and improved understanding of the behavioral repertoire. What can zebrafish 'do', and how does their altered brain function translate into behavioral actions? To help address these questions, we have developed a detailed catalog of zebrafish behaviors (Zebrafish Behavior Catalog, ZBC) that covers both larval and adult models. Representing a beginning of creating a more comprehensive ethogram of zebrafish behavior, this effort will improve interpretation of published findings, foster cross-species behavioral modeling, and encourage new groups to apply zebrafish neurobehavioral paradigms in their research. In addition, this glossary creates a framework for developing a zebrafish neurobehavioral ontology, ultimately to become part of a unified animal neurobehavioral ontology, which collectively will contribute to better integration of biological data within and across species.

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A rapidly aging global population has motivated the development and use of models for human aging. Studies on aging have shown parallels between zebrafish and humans at the internal organization level; however, few parallels have been studied at the whole-organism level. Furthermore, the effectiveness of exercise as a method to mitigate the effects of aging has not been studied in zebrafish. We investigated the effects of aging and intermittent exercise on swimming performance, kinematics and behavior. Young, middle-aged and old zebrafish (20-29, 36-48 and 60-71% of average lifespan, respectively) were exercised to exhaustion in endurance and sprint swimming tests once a week for four weeks. Both endurance and sprint performance decreased with increased age. Swimming performance improved with exercise training in young and middle-aged zebrafish, but not in old zebrafish. Tail-beat amplitude, which is akin to stride length in humans, increased for all age groups with training. Zebrafish turning frequency, which is an indicator of routine activity, decreased with age but showed no change with exercise. In sum, our results show that zebrafish exhibit a decline in whole-organism performance and trainability with age. These findings closely resemble the senescence-related declines in physical ability experienced by humans and mammalian aging models and therefore support the use of zebrafish as a model for human exercise and aging.

Altered neurological function will generally be behaviourally apparent. Many of the behavioural models pioneered in mammalian models are portable to zebrafish. Tests are available to capture alterations in basic motor function, changes associated with exteroceptive and interoceptive sensory cues, and alterations in learning and memory performance. Excepting some endpoints involving learning, behavioural tests can be carried out at 4 days post fertilization. Given larvae can be reared quickly and in large numbers, and that software solutions are readily available from multiple vendors to automatically test behavioural responses in 96 larvae simultaneously, zebrafish are a potent and rapid model for screening neurological impairments. Coupling current and emerging behavioural endpoints with molecular techniques will permit and accelerate the determination of the mechanisms behind neurotoxicity and degeneration, as well as provide numerous means to test remedial drugs and other therapies. The emphasis of this review is to highlight unexplored/underutilized behavioural assays for future studies. This article is part of a Special Issue entitled Zebrafish Models of Neurological Diseases.

Novel field measurements of critical swimming speed (Ucrit) and oxygen uptake ( Mo2) in three species of adult Pacific salmon Oncorhynchus spp. up to 3·5 kg in body mass were made using two newly designed, mobile Brett‐type swim tunnel respirometers sited at a number of field locations in British Columbia, Canada. Measurements of Ucrit, which ranged from 1· 68 to 2·17 body lengths s−1, and maximum Mo2, which ranged from 8·74 to 12·63 mg O2 kg−1 min−1 depending on the species and field location, were judged to be of similar quality when compared with available data for laboratory‐based studies. Therefore high quality respirometry studies were possible in the field using adult wild swimming salmonids. In addition, the recovery of wild adult Pacific salmon from the exhaustive Ucrit swim test was sufficiently rapid that swimming performance could be repeated with <1 h of recovery time between the termination of the initial swim test and the start of the second test. Moreover, this repeat swimming performance was possible without routine Mo2 being reestablished. This result suggests that wild adult salmon are capable of carrying a moderate excess post‐exercise oxygen consumption without adversely affecting Ucrit, maximum Mo2 or swimming economy. Such capabilities may be extremely important for timely migratory passages when salmonids face repetitive hydraulic challenges on their upstream migration.