Fishes Used for Entertainment


Fishes are held captive in aquariums and as pets. Globally, there are more than two million public aquariums and homes that hold fish captive. In the US, between 10 to 13% of households keep fish as pets, with an average of 8 to 9 fish per household. The majority of captive fishes are in the US, followed by Europe and Japan. There are more than 1,800 species of fishes in the aquarium trade (about half are saltwater species, the other half are freshwater species). The majority of fishes kept as pets are freshwater fish.

fishes are captured from the wild

There are only a few saltwater species that successfully breed in captivity on a commercial scale, so the vast majority of saltwater fish are taken from the wild. Fish are mostly taken from reefs in the Coral Triangle Region (the waters off Indonesia, Malaysia, Papua New Guinea, the Philippines, Solomon Islands and Timor-Leste). Twenty to 24 million fish are captured from the oceans every year to be sold in the aquarium trade.

capture is cruel

Sodium cyanide, a highly toxic compound that stuns fish by suffocating them, is widely used in their capture. After being squirted with cyanide, fish suffer “severe gasping, followed by loss of balance and a complete loss of all respiratory activity.” There is a 75% mortality rate for fish who are sprayed. 50% of fish in the surrounding area, but not sprayed directly, are also killed by it. Eleven million wild-caught fish are imported every year to the US, and six to ten million of those fish are caught using cyanide.

In just Philippines alone, five metric tons of cyanide are used to capture fish every year. Cyanide use also kills the coral reef. For each live fish caught with cyanide, it destroys about a square yard of coral. Even in low doses, cyanide can bleach coral. The ecosystem collapses without coral, as it provides animals with food, shelter, and breeding grounds.

Fishes are also caught using nets, which scare and injure them, as well as damage the coral reef. Many fish who are captured are raised from deep water too quickly. These fish suffer decompression injuries, such as parts of their gut being forced out through their mouths and anuses, their swim bladders bursting, and their eyes bulging out. Some collectors bring fish to the surface immediately and pierce the fish’s inflated swim bladder with a needle to keep it from bursting.

In the US, the Lacey Act bans the importation of wild animals caught in violation of another country’s law. (The Philippines, Sri Lanka, and Indonesia ban the use of cyanide to catch fish). But currently, US agencies do not test imported fish for traces of cyanide.

Fishes are also caught using nets, which scare and injure them, as well as damage the coral reef, and through spearing. Many who are caught are raised from deep water too quickly. These fishes suffer decompression injuries, such as parts of their gut being forced out through their mouths and anuses, their swim bladders bursting, and their eyes bulging out. Some collectors bring fishes to the surface immediately and pierce the fish’s inflated swim bladder with a needle to keep it from bursting.

Aquariums have made dozens of attempts since the 1970s to display a captive great white shark. Most of those attempts ended in their death. In the 2000s, the Monterey Bay Aquarium acquired a baby shark that became the first great white to survive in captivity for more than 16 days. He was on display for more than six months before he was released back into the ocean. During those 6 months, he killed two other sharks. Over the next six years, the aquarium caught and displayed five more baby sharks. They stayed eleven days up to five months. The sharks developed sores from bumping to the side of their tanks. Great white sharks roam the open ocean for long distances without any obstructions. A great white shark named Nicole who was caught and tagged, traversed the Indian Ocean twice in one year, swimming from the western coast of South Africa to Western Australia — and back. She swam the first leg in only three months. In 2016, an adult great white shark was caught and put on display in an aquarium in Japan, but he was dead within three days.

suffering during transport

Transport is very stressful to fishes. The major cause of death when transporting fish is stress-induced deaths. After collection, fish are put in plastic containers or bags with very little water. Fishes barely have room to move. Aggressive fishes may be placed in bags which they cannot see through. Before being shipped to a wholesale facility, fishes are usually starved for 24 to 48 hours to prevent the small amount of water from being contaminated with their excrement. Their dorsal spines, which can pierce the plastic bag, are often cut off.

The transport process can be days long, even though studies suggest that travel time should be kept under 40 hours. When fishes get to their destination, they are taken out of the bags and quarantined.  When they are moved around at the wholesale facility, they are taken out of water, which is very stressful as they cannot breathe as well in air as in water. They are moved using nets and other implements which cause them injury. Water temperature, quality, and oxygen levels may not be similar to their natural habitat.

breeding in captivity

Breeding saltwater fishes is difficult because most saltwater fishes are pelagic spawners, meaning they deposit their eggs into the open water. When the fishes hatch, the babies are helpless: they have no mouth, eyes, gastrointestinal tract, or nervous system, so it’s very hard to keep these animals alive in captivity. It takes a lot of time and equipment, which makes it very expensive to breed saltwater fishes. Many are still attempting to though, even though those bred in captivity do not live very long. Yellow tang can over 30 years in the wild, but one breeder has only been able to keep one alive for 42 days. The longest anyone has been able to raise a yellow tang in captivity has been around 80 days. That’s less than 1% of their lifespan. A public aquarium breeding boarfishes, who live 26 years in the wild, were only able to keep them alive for 26 days, again less than 1% of their lifespan.

Other saltwater fishes who are commonly bred in captivity include clownfishes and seahorses. Jellyfishes and some cephalopods, such as cuttlefishes, are also bred.

The majority of freshwater fishes in the aquarium trade, like goldfishes, guppies, angelfishes, and kois, can be bred in captivity. Many times during their lives, like when their eggs are taken, they are moved into a different tank, or moved to be sold, they are netted, taken out of water, and handled roughly. One facility alone sells two million captive bred fishes every year. It is estimated that more than 250 million goldfishes are bred every year.

Photo of koi fishes intensively confined in a tank

CC Bernard Spragg NZ

Wild Animals Deserve Freedom

Fishes are held captive in conditions that cannot adequately mimic their natural habitat. There are millions to billions of animals held captive in aquariums in the US that live in inadequate environments that do not meet their needs. Many tanks don’t regulate water temperature as needed or provide environmental enrichment. Fishes suffer from disease outbreaks. Tanks that are too small (or contain too many animals) lead to lack of oxygen and developmental deformities in fish.

millions of fishes die to stock aquariums

Small fishes can live in captivity for three to five years, and medium to large fishes can live more than ten years. 80% of all wild-caught fishes die before they are sold. Those that survive long enough to be bought by hobbyists or people who consider them to be pets are extremely likely to be dead in under a year. It is estimated that 98% of all wild-caught fishes die within a year. Many die within days of being purchased.


Revealing the appetite of the marine aquarium fish trade: the volume and biodiversity of fish imported into the United States by A. Rhyne et al. in PLoS One Vol. 7(5) (2012).

From ocean to aquarium: the global trade in marine ornamental species by Colette Wabnitz et al., UNEP World Conservation Monitoring Centre (2003).

Effects of cyanide exposure on Dascyllus aruanus, a tropical marine fish species: lethality, anaesthesia and physiological effects by M. Hanawa et al. in Aquarium Sciences & Conservation Vol. 2(1) (1998).

Proceedings of the International Cyanide Detection Testing Workshop edited by Andrew Bruckner & Glynnis Roberts in Orlando, FL (2008).

The Horrific Way Fish Are Caught for Your Aquarium—With Cyanide by Rachael Bale, National Geographic (2016).

People Are Killing Millions Of Fish Each Year Just To Stock Aquariums by Elizabeth Alberts, The Dodo (2017).

How It’s Made – Aquarium Fish by How Its Made (2016).

Saving Nemo: transforming the marine aquarium Industry by World Wildlife Fund.