Refinement Database

Database on Refinement of Housing, Husbandry, Care, and Use of Animals in Research

This database, created in 2000, is updated every four months with newly published scientific articles, books, and other publications related to improving or safeguarding the welfare of animals used in research.

Tips for using the database:

  • This landing page displays all of the publications in the database.
  • Use the drop-down menus to filter these publications by Animal Type, Setting, and/or Topic.
  • Clicking on a parent category (e.g., Rodent) will include publications relating to all the items in that category (e.g., Chinchilla, Gerbil, Guinea Pig, etc.).
  • You may also add a keyword to further narrow your search.
  • Please note that at this time, only publications dated 2010 or later (with some exceptions) can be filtered by Animal Type and Topic, and only publications dated 2020 or later (with some exceptions) can be filtered by Setting. Most publications older than 2010 can only be searched by keyword. 
Lambert, H., Cornish, A., Waley, D. 2024. The value of regulating stocking densities in aquaculture must not be dismissed: A reply to Saraiva et al. 2022. Frontiers in Veterinary Science 10.

We would like to rebut the argument made by Saraiva et al. (1) in their paper “Finding the “golden stocking density”: a balance between fish welfare and farmers' perspectives,” that stocking densities should not be...

Almeida, M. M., Cabrita, E., Fatsini, E. 2023. The use of sand substrate modulates dominance behaviour and brain gene expression in a flatfish species. Animals 13(6), 978.

Physical complexity adds physical enrichment to rearing conditions. This enrichment promotes fish welfare and reduces detrimental characteristics that fish develop in captivity. Senegalese sole (Solea senegalensis) is an important species for European aquaculture, where it...

Diao, W., Jia, R., Hou, Y. et al. 2023. Effects of stocking density on the growth performance, physiological parameters, antioxidant status and lipid metabolism of Pelteobagrus fulvidraco in the integrated rice-fish farming system. Animals 13(11), 1721.

Pelteobagrus fulvidraco is a freshwater fish commonly raised in rice fields, yet the optimal stocking density for this species remains unknown. Therefore, this study aimed to investigate the appropriate stocking density of P. fulvidraco in...

Matrai, E., Chan, H. Y. A., Leung, F. M. et al. 2023. Point for enrichment, point for welfare—Testing use of a laser pointer with Arapaima gigas. Animals 13(8), 1370.

The arapaima (Arapaima gigas) is one of the largest freshwater fish species, known to exceed 3 m in total length. It is listed as Data Deficient by the IUCN. A. gigas is native to the...

Baßmann, B., Hahn, L., Rebl, A. et al. 2023. Effects of stocking density, size, and external stress on growth and welfare of African catfish (Clarias gariepinus Burchell, 1822) in a commercial RAS. Fishes 8(2), 74.

The effects of semi-intensive (100 kg m−3), intensive (200 kg m−3), and super-intensive (400 kg m−3) stocking densities on the growth and welfare of African catfish (Clarias gariepinus) were investigated under commercial production conditions. Plasma...

Xu, C., Hou, M., Su, L. et al. 2022. The effect of environmental enrichment on laboratory rare minnows (Gobiocypris rarus): Growth, physiology, and behavior. Animals 12(4), 514.

Environmental enrichment is a method to increase environmental heterogeneity, which may reduce stress and improve animal welfare. Previous studies have shown that environmental enrichment can increase the growth rate, decrease aggressive and anxiety-like behaviors, improve...

Ojelade, O. C., Durosaro, S. O., Akinde, A. O. et al. 2022. Environmental enrichment improves the growth rate, behavioral and physiological response of juveniles of Clarias gariepinus under laboratory conditions. Frontiers in Veterinary Science 9, 980364.

Environmental enrichment (EE) improves the growth rate and welfare of some cultured fishes. However, most cultured fish species are raised in non-enriched housing conditions. Clarias gariepinus is an important commercial fish species, but little is...

Spitzer, H. B., Meagher, R. K., Proudfoot, K. L. 2022. The impact of providing hiding spaces to farmed animals: A scoping review. PLOS ONE 17(11), e0277665.

Many wild animals perform hiding behaviours for a variety of reasons, such as evading predators or other conspecifics. Unlike their wild counterparts, farmed animals often live in relatively barren environments without the opportunity to hide...

Ojelade, O. C., Durosaro, S. O., Akinde, A. O. et al. 2022. Environmental enrichment improves the growth rate, behavioral and physiological response of juveniles of Clarias gariepinus under laboratory conditions. Frontiers in Veterinary Science 9, 980364.

Environmental enrichment (EE) improves the growth rate and welfare of some cultured fishes. However, most cultured fish species are raised in non-enriched housing conditions. Clarias gariepinus is an important commercial fish species, but little is...

Saraiva, J. L., Rachinas-Lopes, P., Arechavala-Lopez, P. 2022. Finding the “golden stocking density”: A balance between fish welfare and farmers’ perspectives. Frontiers in Veterinary Science 9, 930221.

The effects of stocking density on fish welfare are complex and involve many interacting parameters. This complex relationship between fish welfare, stocking density and influencing factors make it challenging to define a specific optimal (“golden”)...

Lee, W.-Y., Lan, K.-W., Chang, H.-H. et al. 2022. Residency and swimming behavior of Acanthopagrus schlegelii, Trachinotus blochii, and Acanthopagrus latus in relation to artificial reef models in a captivity experiment. Applied Animal Behaviour Science 257, 105778.

Global capture fisheries production has declined rapidly over the past decades because of the growing demand for fisheries resources. To restore fisheries resources, artificial reefs (ARs) are deployed on the seafloor to provide new habitats...

Thomas, M., Reynaud, J.-G., Ledoré, Y. et al. 2022. Enrichment in a fish polyculture: Does it affect fish behaviour and development of only one species or both? Applied Sciences 12(7), 3674.

Physical enrichment of structures has been used for the last decades in aquaculture to improve fish production and welfare. Until now, this enrichment has been practiced in fish monoculture but not in fish polyculture. In...

Zhang, Z., Fu, Y., Zhang, Z. et al. 2021. A comparative study on two territorial fishes: The influence of physical enrichment on aggressive behavior. Animals 11(7), 1868.

Intraspecific aggression is detrimental to body/fin damage, physiological stress, and other problems in aquaculture. Environmental enrichment has been proposed to have positive effects on fish aggressive behavior, physiological stress, and fish welfare, but there are...

Alnes, I. B., Jensen, K. H., Skorping, A. et al. 2021. Ontogenetic change in behavioral responses to structural enrichment from fry to parr in juvenile Atlantic salmon (Salmo salar L.). Frontiers in Veterinary Science 8, 638888.

Enrichment is widely used as a tool for studying how changes in environment affect animal behavior. Here, we report an experimental study investigating if behaviors shaped by stimuli from environmental enrichment depending on the stage...

Jones, N. A. R., Webster, M. M., Salvanes, A. G. V. 2021. Physical enrichment research for captive fish: Time to focus on the DETAILS. Journal of Fish Biology 99(3), 704-725.

Growing research effort has shown that physical enrichment (PE) can improve fish welfare and research validity. However, the inclusion of PE does not always result in positive effects and conflicting findings have highlighted the many...

Brandão, M. L., Dorigão-Guimarães, F., Bolognesi, M. C. et al. 2021. Understanding behaviour to improve the welfare of an ornamental fish. Journal of Fish Biology 99(3), 726-739.

Some common practices in aquaculture, ornamental trade and fish facilities may disturb the behavioural repertoire of fish and its natural adaptive value, reducing welfare and impairing fish production. Hence, it is necessary to understand fish...

Monreal-Pawlowsky, T., Vaicekauskaitė , R., Palencia Membrive, G. et al. 2021. Goal-oriented behavioural and environmental enrichment in aquarium species. Journal of Zoo and Aquarium Research, 9(4), 273-280.

Environmental enrichment is a common tool used in zoo and aquarium settings to provide mental and physical stimulation to animals under human care. This paper aims to present a primary approach to goal-oriented environmental and...

Janhunen, M., Piironen, J., Vainikka, A. et al. 2021. The effects of environmental enrichment on hatchery-performance, smolt migration and capture rates in landlocked Atlantic salmon. PLOS ONE 16(12), e0260944.

Enrichment of rearing environment with natural elements has been suggested to improve the welfare and post-release survival of cultured fish. We studied the combined effects of shelter structures, periodical water flow and water level changes...

da Silva, A., Lima, M. R., Meletti, P. C. et al. 2020. Impact of environmental enrichment and social group size in the aggressiveness and foraging activity of Serrapinnus notomelas. Applied Animal Behaviour Science 224, 104943.

Fish are widely used in scientific research, and many species are bred for ornamental purposes and human consumption. Despite the large number of fish kept in captivity, research on the welfare of these animals has...

Arechavala-Lopez, P., Caballero-Froilán, J. C., Jiménez-García, M. et al. 2020. Enriched environments enhance cognition, exploratory behaviour and brain physiological functions of Sparus aurata. Scientific Reports 10, 11252.

Environmental enrichment is considered as a recommended tool to guarantee or improve the welfare of captive fish. This study demonstrates for the first time that structural environmental enrichment enhances cognition, exploratory behaviour and brain physiological...

Thoré, E. S. J., Brendonck, L., Pinceel, T. 2020. Conspecific density and environmental complexity impact behaviour of turquoise killifish (Nothobranchius furzeri). Fish Biology 97(5), 1448–1461.

Fish models are essential for research in many biological and medical disciplines. With a typical lifespan of only 6 months, the turquoise killifish (Nothobranchius furzeri) was recently established as a time- and cost-efficient model to...

Arechavala-Lopez, P., Saraiva, J. L. 2019. Welfare of Cultured and Experimental Fishes. Basel, Switzerland: MDPI, 132 pages.

This open access book is a printed edition of the Special Issue on Welfare of Cultured and Experimental Fishes that was published in the journal Fishes. The PDF is free for download.

Zhang, Z., Zhang, X., Li, Z. et al. 2019. Effects of different levels of environmental enrichment on the sheltering behaviors, brain development and cortisol levels of black rockfish Sebastes schlegelii. Applied Animal Behaviour Science 218, 104825.

Environmental enrichment is a promising way to increase the fitness and survival of fish released for stock enhancement and biological conservation programs. However, the effects of enrichment in different studies on the fish behavior, physiology...

Solås, M. R., Skoglund, H., Salvanes, A. G. V. 2019. Can structural enrichment reduce predation mortality and increase recaptures of hatchery-reared Atlantic salmon Salmo salar L. fry released into the wild? Journal of Fish Biology 95(2), 575-588.

Captive-reared fish often have poor survival in the wild and may fail to boost threatened populations. Enrichment during the nursery period can in some circumstances generate a broader behavioural repertoire than conventional hatchery production. Yet...

Jones, N. A. R., Spence, R., Jones, F. A. M. et al. 2019. Shade as enrichment: Testing preferences for shelter in two model fish species. Journal of Fish Biology 95(4), 1161-1165.

We compared preferences shown by zebrafish (Danio rerio) and three-spined stickleback (Gasterosteus aculeatus) for shelter provided by above-tank shade and artificial plants. Zebrafish showed no preference for either shelter, whereas sticklebacks showed a preference for...