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World’s First Venomous Crustacean Discovered

—Cave-dwelling animals uses neurotoxin to kill their prey and digest it before eating.


An article on Nature re-described Xibalbanus tulumensis—a Remipedia animal that was first discovered in 1987—as the first crustacean known to use venom for hunting. *Image source: BJÖRN VON REUMONT / NATURAL HISTORY MUSEUM

It happens sometimes that you eat crab and shrimp and get poisoned, but mostly these incidents are categorized as food poisoning.  Occasionally, people eat actually venomous crabs, such as Zozymus aeneus, which possess exogenous saxitoxin.

However, people have not discovered any crustaceans that can produce venom like spiders, centipedes or hornets. And today, we have a breakthrough.

A new study published on Nature, re-describe Xibalbanus tulumensis, a Remipedia animal that was first discovered in 1987. Scientists found that this centipede-alike animal can hunt its prey like a spider uses venom.

This crustacean live in Anchialine Caves that located in Yucatán Peninsula, which separates the Caribbean Sea and from the Gulf of Mexico. Its generic name, Xibalbanus, comes from the underworld in Maya mythology, Xibalba, ruled by the Maya death gods and their helpers. The specific epithet, tulumensis, suggests that its discovery spot was Tulum. Currently, there is still some debates about its generic name and scientists—including the author of the study published on Nature—proposed to name it as Speleonectes. But it is obvious that the name Xibalbanus seems much cooler and more legendary, so we just call it as Xibalbanus regardless of the academic rules and controversy.

 rfonlHDNMfVlJp-1XZlB3KbGMKt_f8rMR8IVEw5I_nCpAQAAWAIAAFBOIn 2007, researchers discovered structures on the animals’ front claws that resemble hypodermic needles, leading to speculations that they may be injecting something into their prey. This speculation is now proved to be true. The animal has an internal venom producing mechanism and it can inject venom into its prey via its front claws.

Researchers also analyzed their venom and found that the crustaceans’ venom is composed predominantly of peptidases, enzymes that play roles in digestion and are also found in rattlesnake venom. The venom from the crustacean also contains a toxin that is very similar to a paralysis-inducing neurotoxin firstly discovered in spiders in 2010. The researchers speculated that the neurotoxin can stop their prey getting away and with the help of the peptidases, the prey will turn into a mug of milkshakes.

Although venom is not uncommon in arthropod such as scorpions, spiders, centipedes and wasps, it has never before been found in any of the 70,000 known crustaceans, a subgroup of arthropods that conquer the sea, including crabs and shrimp. Why it is so rare in the subgroup still remains an open question. Scientists infer that the reason might be that the diet of crustaceans is more varied than that of venomous predators—animals hunt by venom has relatively simple eating patterns and they don’t have a lot of choices as crustacean do.

Whether the venom has an effect on humans is an unknown question yet. We sometimes hear of cave divers dying under mysterious conditions, and scientists wonder if remipedes should be responsible for this—maybe, the Maya know the answer after all.

SourceNature News,First venomous crustacean discovered
Image sourcenature.com; en.wikipedia.org