The fish that shoots its predators

When attacked, this small fish injects a venom that disorientates and weakens its predators.

CROCS. The blennies are a family of benthic fish distributed throughout the seas. They are usually small (about 5 cm), very colorful and sometimes striated. Some species are appreciated by aquarists and others are characterized by the presence in the lower jaw of two oversized canines, which form genuine fangs. These fish, like Meiacanthus nigrolineatus who live in the Red Sea, use their two teeth to inject venom and thus defend themselves against predators (mainly groupers).

Three toxins to escape

But unlike most other poisonous fish (more than 2,000 species are and mostly via backbones), the Meiacanthus bite is painless in the journal Current Biology of Australian researchers at the University of Queensland. They were able to take the venom by biting cotton swabs and then injecting them into mice. There was no sign of pain in the mice: "The venom of the fennel blennies was painless in mice was a big surprise." Most poisonous fish cause mammals to experience violent and immediate pain, "explains Bryan Fry, One of the authors of the publication.

The analysis of the venom revealed the presence of three different toxins. None of the three are found in other fish families. It is a neuropeptide similar to that of certain poisonous snails, an enzyme found in the venom of scorpions and snakes, and a compound similar to opiate substances used to relieve pain such as fentanyl or oxycodone .

The researchers assume that when attacked, Meiacanthus defends itself by biting its aggressor and injecting its venom causing a drop in tension and leaving the predator in a state of daze, unable to pursue its prey, escape.

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