Sabre-tooth fish injects predators with heroin-like venom

Posted April 04, 2017

These brightly coloured blennies are a popular choice for home aquariums, but it turns out they harbour a fascinating evolutionary secret in their (relatively) giant fangs.

Stepping away from the traditional take on chemical defense, fang blennies turned to venom whose neuropeptide and opioid components seem to cause a sudden drop in blood pressure, leaving a would-be predator dazed an unable to pursue the fish.

In new experiments using lab mice, Fry and colleagues found that the rodents that were injected with the fish venom did not show signs of pain. What is unusual is that the bite is entirely painless, because the venom contains opioids that act like an analgesic instead of causing pain. When the team of scientists injected the paws of mice with fang blenny venom, they did not seem to appear distressed; but, their blood pressure "plummeted by almost 40 percent".

An analysis of the venom found three venom components - a neuropeptide that occurs in cone snail venom, a lipase similar to one from scorpions, and an opioid peptide.

"If you had such a big crash in blood pressure, you would immediately feel faint and dizzy", said study researcher Nicholas Casewell, from Liverpool School of Tropical Medicine.

The reef is one of the Australian habitats for the fang blenny but warmer ocean temperatures are thought to have caused destructive coral bleaching. This offers an entirely new avenue for the development of novel painkillers. They don't make use this venom for capturing their prey. After putting the angry blenny back in its tank, they would extract the venom from the swab. One causes mild pain, explaining Losey's discomfort when he was bitten.

Bryan Fry: While we have known for a long time that fang blennies exist, their venom system has remarkably never been investigated.

If you want to see evolution at its most handsome and deadly, look no further than this tiny fish that puts its predators into a drugged stupor.

Unlike the toxins emitted by other poisonous fish, the venom isn't lethal.

The Voice final marred by stage invasion and Sir Tom Jones swearing
As the victor , Mo will receive a recording contract with Polydor Records, home to artists such as Take That and Ellie Goulding. Instead, the victor will be bundled straight into the studio and will release a Winner's EP in the coming weeks.

Scientists found that other fang blennies and small fishes that aren't venomous mimic the colors and patterns from the venomous fang blennies. "While the feeling of pain is not produced, opioids can produce sensations of extremely unpleasant nausea and dizziness", says Brian Fry.

Could new drugs be found in its unique venom?

The fang blenny is no bigger than 3 inches, and it has two large teeth (compared to their body size) that are filled with venom.

This is so effective that other, non-venomous species have evolved to look like the blenny.

Now an worldwide team of biologists has finally discovered what compounds are found in the venom that blennies from the Meiacanthus genus readily injected in Losey's skin back in the '70s.

Dr Casewell said: "These unassuming little fish have a really quite advanced venom system, and that venom system has a major impact on fishes and other animals in its community".

"If we lose the Great Barrier Reef, we will lose animals like the fang blenny and its unique venom".

Fry said the findings bolster the need to protect the Great Barrier Reef and other fragile ecosystems.