An incredible new discovery involving a tiny fish that swims in the Great Barrier Reef in the Pacific Ocean near Australia, and can also be found in many home aquariums, could lead to breakthroughs in medicine. The fish, which is known as the fang blenny, has a defense mechanism that involves injecting predators with a substance similar to heroin or opioids in order to slow their enemies down.

It’s a fascinating finding that could lead to the development of new types of painkillers as an alternative to opioids, which are beset with problems including addiction and the risk of overdose. Scientists will need to conduct many more studies and tests before such a medicine would be available on the market, but it’s potentially a big step toward finding a solution to the opioid epidemic.

Fang blennies are bottom feeders that can be found near reefs. Like many species that rely on reefs, climate change is a big threat. Scientists say species like this that could help humankind are a good reason to care about global warming and its effects on the environment.

The fang blenny has two large canine teeth sticking out of its lower jaw, and a prick from these two-inch fishes will cause a sudden drop in blood pressure in would-be predators or any human that happened to get too close.

When scientists examined the venom closer, they were in for a surprise, according to the Cell Press statement: “When the researchers did a proteomic analysis of extracted fang blenny venom, they found three venom components–a neuropeptide that occurs in cone snail venom, a lipase similar to one from scorpions, and an opioid peptide. And, surprisingly, when they injected the blenny venom into lab mice, the mice didn’t show any signs of pain.”

“For the fang blenny venom to be painless in mice was quite a surprise,” study co-author Bryan Fry of University of Queensland said in the statement. “Fish with venomous dorsal spines produce immediate and blinding pain. The most pain I’ve ever been in other than the time I broke my back was from a stingray envenomation. ‘Sting’ray sounds so benign. They don’t sting. They are pure hell.”

“By slowing down potential predators, the fang blennies have a chance to escape,” says Fry. “While the feeling of pain is not produced, opioids can produce sensations of extremely unpleasant nausea and dizziness [in mammals].”