Studying zebrafish in their natural habitats can help inform how the model organisms are studied and reared in research facilities, but finding the real wild types means stepping far outside the lab.

Depicted on the cover is a shallow pool of turbid water, running over bedrock, lime, and silt, that connects to the Kaveri River in Kallahalli, India. Here, a field trip to study the natural acoustic properties of zebrafish habitats found fish swimming in loose shoals of 5 to 10 individuals.

See Neff

Administration of an animal research program must go on—regardless of how large or small the staff supporting that program may be. Large institutions will often have dedicated research offices to provide administrative support, as well as enough staff for each and every animal- and administrative-related task that needs tending. Smaller programs don’t always have the same luxury of manpower and time, but they must provide the same level of animal care and program support all the same. A Comment this month shares experiences from administering a small animal research program and tips for others facing similar challenges.

See Keator et al.

Zebrafish will learn to fear an aversive stimulus. That stimulus, however, need not be pain, nor involve conspecifics. Robotic replicas that mimic zebrafish—a trio of which are depicted on the cover illustration and deployed in a new Research Article—can do the trick.

The refined fear-conditioning paradigm may prove useful in behavioural pharmacology, allowing researchers to take advantage of the high-throughput potential of zebrafish to explore the effects of aversive experiences and test potential therapeutics.

See Macrì et al.

To track disease progression and evaluate the potency of a potential treatment, researchers can look to a number of different measures in their mice. That includes their behavior, which digital vivariums can capture continuously and non-invasively.

A new research article shows how monitoring mice in motion can help researchers predict terminal endpoints and assess drug efficacy in the ES-2 ovarian cancer model.

See Carbonell et al.

Research into the microbiome has found another model organism: the zebrafish. Genetically tractable and relatively easy to maintain in the lab, the zebrafish has been a valuable animal model for studying development and a growing number of diseases. With a microbiome that can be manipulated relatively easily as well, the zebrafish is now helping researchers to better understand these complex and sometime elusive communities of bacteria, fungi, and viruses and how they influence host health and disease.

See Stagaman et al

When considering what animal to use to model a particular disease, mice are a frequent first choice. Mice will no doubt be important as researchers rush to understand the pandemic SARS-CoV-2 virus and find ways to prevent and to treat the resulting disease. Mice though likely won’t stand alone—before all is said and done, hamsters, ferrets, different species of nonhuman primates, and more may find themselves with roles to play in infectious disease labs around the world searching for a cure to COVID-19.

See Eisenstein

Magnetic resonance imaging (MRI) is a non-invasive imaging modality that can help bridge neuroscience research in nonhuman primates with the humans they are intended to model. But, studies with such animals tend to involve small numbers of subjects, and the task of adapting human equipment and tools to nonhuman primates means labs are often coming up with their own solutions to collecting and analyzing MRI data. Data sharing may help researchers make the most of those animals. With discussions about standards and tool building ongoing, a growing number of labs in the nonhuman primate research community are working to bring their MRI datasets together.

See Neff

Depicted on the cover this month are 24 h post-injection zebrafish embryos (72 h post-fertilization) engrafted with PC3 human prostate cancer cells. Zebrafish bearing human cancer cells and fruit flies mirroring the mutation profiles of particular cancer patients may be poised to form ‘avatar armies:’ large numbers of personalized models that could be used to test how an individual’s cancer may progress and respond to treatment.

See Neff

Goblet cells both secrete mucus (green) and sample luminal antigen (red) in the intestine. In Lab Animal’s inaugural Protocol article, the authors describe in step-by-step detail a procedure they developed to label goblet cell-associated antigen passages, or GAPs, in the intestines of mice.

See Knoop et al.

Depicted on the cover is the sea anemone Aiptasia, harboring microalgae of the species Breviolum minutum (family Symbiodiniaceae). Aiptasia is one animal being developed as a model of coral, its reef-building relatives that are threatened by climate change and other negative human impacts. Just as mice, flies, and other model systems help researchers identify the cellular and molecular mechanisms that contribute to human health and disease, growing communities in the coral field are starting to look for simpler, more tractable options that can be studied in the lab to understand and ultimately help conserve coral reefs in the field.

See Neff

Sea urchins, such as the Paracentrotus lividus individual gracing our cover this month, have a long history as a lab animal. They’re of socioeconomic and ecological importance, and despite their outward appearance, they are among the most closely related invertebrates to humans. But looking at that sea urchin sitting on the cover—is it male…or is it female? By sight alone it’s impossible to tell, but sex determination can be a necessity for different experiments. Figuring it out used to involve dissection or invasive measures to induce spawning. A new Comment presents a non-lethal option that also reduces the number of animals needed to make the determination

See Paredes and Costas