Trout

Environmental enrichment increases aquatic animal welfare: A systematic review and meta-analysis

With the rapid development of aquaculture and the gradual decrease in fishery resources, aquatic animal welfare (AAW) has received increasing attention from animal protection organisations, government departments, biologists, fish culturists and consumers. Although environmental enrichment (EE) can potentially benefit AAW,...

Year Published: 2022Topics: Environmental EnrichmentAnimal Type: Fish, Other Fish, Salmon, Tilapia, Trout, Zebrafish

Citation: Zhang, Z., Gao, L., Zhang, X. 2022. Environmental enrichment increases aquatic animal welfare: A systematic review and meta-analysis. Reviews in Aquaculture 14(3), 1120–1135.

Simple life, simple minds? How habitat simplification in aquatic ecosystems shape fish cognition

This narrative review synthesises current knowledge on the effects of habitat complexity, defined as the variation in physical structures within ecosystems, on fish cognition, brain morphology, and personality. Globally, habitat complexity is declining through a process known as habitat simplification,...

Year Published: 2026Topics: Environmental Enrichment, Housing, Natural Behavior, PersonalityAnimal Type: Fish, Other Fish, Salmon, Shark & Ray, Tilapia, Trout, Zebrafish

Citation: Klinke, A., Brown, C. 2026. Simple life, simple minds? How habitat simplification in aquatic ecosystems shape fish cognition. Animal Cognition 29(1), 23.

Fish welfare in recirculating aquaculture systems (RAS): The imperative for environmental enrichment (EE)

Aquaculture has become the fastest-growing food production sector worldwide, recently surpassing wild-capture fisheries in total output. This rapid expansion underscores the need to ensure sustainability through robust animal welfare standards. Recirculating Aquaculture Systems (RAS) are increasingly adopted due to their...

Year Published: 2026Topics: Environmental EnrichmentAnimal Type: Fish, Other Fish, Salmon, Tilapia, Trout, Zebrafish

Citation: Fruscella, L., Passantino, A., Kotzen, B. 2026. Fish welfare in recirculating aquaculture systems (RAS): The imperative for environmental enrichment (EE). Animals 16(4).

Respirometer in a box: Development and use of a portable field respirometer for estimating oxygen consumption of large‐bodied fishes

Respirometry has become the standard method for measuring the metabolic rate of fishes. Traditionally, respirometry has required the fish to be kept in captivity and tested under controlled conditions; however, many species do not readily adapt to captivity, and stress...

Year Published: 2020Topics: Biological Sampling & Physiological MeasurementAnimal Type: Fish, Other Fish, Salmon, Tilapia, Trout, Zebrafish

Citation: Byrnes, E. E., Lear, K. O., Morgan, D. L. et al. 2020. Respirometer in a box: Development and use of a portable field respirometer for estimating oxygen consumption of large‐bodied fishes. Journal of Fish Biology 96(4), 1045-1050.

Best practices for non-lethal blood sampling of fish via the caudal vasculature

Blood sampling through the caudal vasculature is a widely used technique in fish biology for investigating organismal health and physiology. In live fishes, it can provide a quick, easy and relatively non‐invasive method for obtaining a blood sample (cf ....

Year Published: 2020Topics: Biological Sampling & Physiological MeasurementAnimal Type: Fish, Other Fish, Salmon, Tilapia, Trout, Zebrafish

Citation: Lawrence, M. J., Raby, G. D., Teffer, A. K. et al. 2020. Best practices for non-lethal blood sampling of fish via the caudal vasculature. Journal of Fish Biology 97(1), 4–15.

Long-term retention of dummy acoustic transmitters in adult brown trout

A group of 36 1+ age class Salmo trutta were surgically implanted with dummy acoustic tags and monitored for 370 days. In total 13 tags were expelled throughout the experiment with an overall tag loss rate of c. 0.035 tags...

Year Published: 2020Topics: Identification MethodAnimal Type: Fish, Trout

Citation: Kennedy, R. J., Evans, D., Allen, M. 2020. Long-term retention of dummy acoustic transmitters in adult brown trout. Journal of Fish Biology 97(4), 1281–1284.

Editorial: Fish welfare in aquaculture and research—where are we going?

Rapid technical developments are taking place in aquaculture, and its production is increasing globally every year by more than 4%. Research is the necessary foundation for politics to define reasonable regulations and recommend guidelines for aquaculture, but also the basis...

Year Published: 2025Topics: Rearing & Weaning, Stocking Density, Welfare AssessmentAnimal Type: Fish, Other Fish, Salmon, Trout, Zebrafish

Citation: Pietsch, C. 2025. Editorial: Fish welfare in aquaculture and research—where are we going? Animals 15(16), 2367.

Mental Health and Well-being in Animals

Since the publication of the first edition of this book, professional and public concern for the well-being of animals has continued to increase throughout the world. Advances in research and technologies have yielded an enormous amount of new knowledge about...

Year Published: 2025Topics: Emotion, Pain, & Sentience, Welfare AssessmentAnimal Type: All/General, Baboon, Bird, Capuchin, Cat, Chicken, Chimpanzee, Crocodile & Alligator, Dog, Equine, Fish, Gibbon, Goat, Lemur, Lizard, Macaque, Marmoset, Nonhuman Primate, Other Animal, Other Nonhuman Primate, Owl Monkey, Parrot, Pig, Rabbit, Reptile, Salmon, Sheep, Snake, Squirrel Monkey, Trout, Turtle & Tortoise, Vervet (African Green Monkey)

Citation: McMillan, F. D. (Ed.) 2025. Mental Health and Well-being in Animals (3rd ed.). CAB International, Oxfordshire, UK. 464 p.

An adaptable, user-friendly score sheet to monitor welfare in experimental fish

Fish are increasingly used as experimental animals across research fields. Currently, around a quarter of all experimental animals used are fish. Less than 20% of these are standard model species. Welfare assessments for experimental fish are in their infancy compared...

Year Published: 2025Topics: Welfare AssessmentAnimal Type: Fish, Other Fish, Salmon, Shark & Ray, Tilapia, Trout, Zebrafish

Citation: Flueck-Giraud, M., Schmidt-Posthaus, H., Bergadano, A. et al. 2025. An adaptable, user-friendly score sheet to monitor welfare in experimental fish. Laboratory Animals 59(2), 226–241.

Quantifying the welfare impact of air asphyxia in rainbow trout slaughter for policy and practice (2025)

The effective improvement of animal welfare requires quantitative methods to compare diverse impacts across practices and policies on a common, relatable scale. The Welfare Footprint Framework (WFF) fulfills this need by providing a standardized welfare impact measure: cumulative time in...

Year Published: 2025Topics: EuthanasiaAnimal Type: Fish, Trout

Citation: Schuck-Paim, C., Alonso, W. J., Pereira, P. A. et al. 2025. Quantifying the welfare impact of air asphyxia in rainbow trout slaughter for policy and practice. Scientific Reports 15(1), 19850.