We are all familiar with the plot of Finding Nemo: a scuba-diving dentist takes a small clownfish, Nemo, from a reef, keeps him in a fish tank in his office, and Marlin (Nemo’s father) goes on a whirlwind adventure to rescue his son. The movie is fraught with humor about “tank life” for Nemo and his new friends, who ultimately escape to the ocean, to a final line of “Now what?” Obviously, Disney’s creative fiction is just that — fiction.
However, many millions of fish are kept in tanks in the real world, for both recreation and research. Although we cannot know the fate of home-kept fish, for fish used in scientific research, there are specific rules for ethical treatment and proper care for fish of all kinds. How and why do scientists use fish in research anyways?
Fish are used in all kinds of research, from biology and medicine to behavior and cognition. They are often small, relatively easy to care for, and their simple lives allow for controlled experiments to be done quickly and easily. The most common species used in labs is the zebrafish, whose transparent embryos allow for detailed study of development, but a wide range of species, from goldfish to sharks and rays, are used in research. Through research, these fish have taught us a lot about gene expression and disease, how biodiversity relates and ecosystem health, and memory and spatial cognition. Here at IUB, researchers have studied knife fish to understand how they communicate through water, and another lab did comparative research on FanTail Darters in aquaria and in the wild to understand their behavior, mating preferences, and how the surrounding environment may influence these preferences.
As we have discussed on the blog before, researchers follow rules and regulations to ensure the ethical and humane treatment of research animals, including fish . In all places where fish are kept and used for research purposes, an Institutional Animal Care and Use Committee (IACUC) reviews research protocols to make sure that fish are cared for in the following ways:
- Ensuring that the fish being studied is the most appropriate species for the investigation.
- Ensuring that the tank that the animals are being kept in provides a healthy environment, is the appropriate size for how many fish are in the tank, and the appropriate species are being housed within the tank.
- Making sure that the fish are fed a species appropriate diet, and quantity of food is appropriate for the animals’ ages.
- That the research being conducted is using the most humane and pain-minimizing methods to investigate their hypotheses.
Unfortunately, this ethic of care does not extend, legally, to non-scientist fish owners, like the general public . There are many disreputable folks involved in the illegal trade of exotic animals, including tropical fish, Poaching for the pet trade harms native environments, and can also have long-lasting effects in new environments if animals escape and become invasive. The exotic pet trade has an additional negative impact on conservation. Photos of people with exotic animals, particularly when shared on social media, are having a detrimental effect on animal conservation. Research shows that these photos lead viewers to believe that 1) it’s ok/safe to be close to and interact with exotic, wild, and/or endangered animals, and 2) that the species in the photos aren’t as endangered as they actually are.
Speaking of conservation: in addition to the scientific knowledge gained from fish research, scientists themselves are on the front lines to preserve fish species and biodiversity for future generations. A particular aspect of research and conservation work is called a “Species Survival Plan” (or SSP) in which scientists at zoos, aquariums, sanctuaries, wildlife parks, and other labs coordinate breeding programs for animals (including the zebrafish!) all across the world in order to preserve their genetic diversity and increase their chance of survival. With climate change already directly impacting ocean habitats, and fish species being some of the most vulnerable, the importance of this work cannot be overstated.
The best place for any fish is in their natural environment. We should be cognizant of our impact on this planet whether we are looking for a research animal (scientists need to source their fish carefully), a pet (don’t participate in the exotic pet trade), or some dinner (consider how your diet impacts the environment), or). While fish may be the low effort pet for many young children, researchers have to do a lot of work to ensure a healthy environment for their fish. Fish should have, at minimum, 1 gallon of water per inch of fish. A three-inch clownfish should have 3 gallons of water; the dentist in Finding Nemo should’ve had a 200-gallon tank to comfortably provide for all his fish! Not your average size for an office.
Above all, be sensitive to the fish’s needs. Blue tangs (Dory-looking fish) especially are sensitive to environmental changes. Like many of the species of fish seen in the movie, blue tang species suffered significantly after the film because people at home did not have the high tech monitoring systems large aquariums use when caring for their saltwater species. Fish in research environments are protected by IACUC protocols and often Association of Zoos and Aquariums accreditation. Unless your home has been approved under this same criteria, Nemo should stay in the ocean where he belongs.
Camera feed from the Kelp Forest environment. Video Credit: Monterey Bay Aquarium on YouTube
Thank you to Susan Glowacz for providing us with helpful resources!
 IACUC protocols are only required for vertebrate animals. However, even though all fish are technically vertebrates, not all fish research needs to go through an IACUC approval process due to the current assumptions about fish cognition. There are some exceptions that have been made for certain invertebrates based on extensive research assessing their cognitive abilities. Even though cephalopods are invertebrates they’re all protected by animal research laws.
 For folks with fish at home, we recommend the guides at Tropical Fish Magazine for thinking about ethical and appropriate care!