Meet The Blob, A Creature That Has Almost 720 Sexes — But No Brain

This remarkable single-celled creature has many superpowers

by GrrlScientist for Forbes | @GrrlScientist

NOTE: This piece was a Forbes Editor’s pick.

The yellow net-like bits are “the blob” (Physarum polycephalum), a plasmodium slime mold that inhabits shady, cool, moist areas, such as decaying leaves and logs. The blob is a unicellular organism that is neither plant, nor mushroom, nor animal.
(Credit: frankenstoen / CC BY 2.5)

If you are in Paris, then you may have the pleasure to meet a mysterious microbeastie, “the blob”, a bright yellow unicellular critter that looks like a fungus but acts like an animal. According to a recent tweet, this peculiar creature will be on public display in Paris starting this weekend. It will be located on the branches of a tree in a vivarium at the Parc Zoologique de Paris — the Paris zoo (formerly known as the Zoo de Vincennes).

The blob is remarkable for many reasons, not the least of which is that it has almost 720 sexes, but also because it has a variety of impressive superpowers, including the ability to move by as much as one centimeter per hour without the aid of legs or fins or wings, the ability to find and digest food despite having no eyes and no stomach, the ability to heal itself in just two minutes if it’s cut in half, the ability to double its size each day and the ability to attain a size of several square kilometres. It’s also nearly impossible to kill.

Several astonishing abilities that the blob and its cousins, the slime molds, show are the ability to solve mazes, to mimic the layout of man-made transportation networks and to choose the healthiest food from a varied menu. The underlying algorithms that guide these organisms’ movements are apparently hard-wired into each cell’s biochemistry. As such, these remarkable behaviors serve to challenge our ideas about biological intelligence.

But that’s not all: blobs can learn and share their knowledge with other blobs, despite lacking a brain (ref).

“It surprises us because it has no brain but is able to learn (…) and if you merge two blobs, the one that has learned will transmit its knowledge to the other”, Bruno David, the director of the Paris Museum of Natural History, told Reuters.

“It behaves very surprisingly for something that looks like a mushroom (…) it has the behavior of an animal; it is able to learn.”

This minibeast’s remarkable abilities and behaviors clearly indicate that we must rethink how intelligence works, and what is required for it to form.

“The blob is a living being which belongs to one of nature’s mysteries”, Dr. David told Reuters.

The blob’s name was inspired by a 1958 sci-fi horror film with the same name where an alien life form goes on a rampage and consumes everything in its path in a small Pennsylvania town.

But what is the blob? We don’t know for sure. It shares traits with the three major kingdoms of life: it eats like an animal, breeds like a mushroom, and is colored like a plant.

“We know for sure it is not a plant but we don’t really [know] if it’s an animal or a fungus,” Dr. David told Reuters.

A handout picture released by the French National Centre for Scientific Research on 27 April 2016 shows a colony of the single-celled protist, Physarum polycephalum.

Currently, taxonomists have classified the blob, Physarum polycephalum, and its other 900 or so relatives into the kingdom of protists (protozoa) because it shares some traits with those life forms.

The blob is a plasmodium, informally known as a slime mold. Slime molds are a group of microscopic organisms that are superficially similar to bacteria, except they’re bigger. Unlike bacteria, they have a distinct nucleus and other cell structures, so they are more similar to plant and animal cells than to bacteria. Plasmodiums are unusual because each individual cell contains many nuclei (most animal cells have just one nucleus).

Although the name, plasmodium, may be unfamiliar, you have already heard of plasmodiums without even realizing it because malaria are members of this taxonomic group, too. Unlike malaria — and unlike the blob’s sci-fi namesake — slime molds do not harm people.

When conditions are good and food is plentiful, a slime mold leads a solitary life as a single cell, but when conditions become more challenging, such as when food becomes scarce, individuals come together to form a bright yellow colony that resembles a thin layer of scrambled eggs. This colony then goes on a rampage, seeking out and devouring bacteria, molds, decaying leaves and other material.

In captivity, slime molds are fond of oat flakes and detest anything that’s salty.

But back to the almost 720 sexes that these beasties have. You are, no doubt, having trouble wrapping your head around that, and you may be wondering about the dating possibilities that exist for these wee beasties. Basically, slime molds can only mix their genetic material when they possess a compatible set of mitochondrial genes known as matA, matB, and matC, each of which has as many as 16 variations (ref). So it would appear that slime molds lead very complicated social lives.

The blob will be on public display starting Saturday, 19 October, at the Paris Zoological Park, which is part of the Paris Museum of Natural History.

Video courtesy of BioGraphic.

Originally published at Forbes on 17 October 2019.

The Startup

Medium's largest active publication, followed by +525K people. Follow to join our community.

𝐆𝐫𝐫𝐥𝐒𝐜𝐢𝐞𝐧𝐭𝐢𝐬𝐭

Written by

Evolutionary ecologist & ornithologist, science journalist. Freelance, job hunting. Writes about science for Forbes. Formerly: The Guardian. Always: Ravenclaw.

The Startup

Medium's largest active publication, followed by +525K people. Follow to join our community.

Welcome to a place where words matter. On Medium, smart voices and original ideas take center stage - with no ads in sight. Watch
Follow all the topics you care about, and we’ll deliver the best stories for you to your homepage and inbox. Explore
Get unlimited access to the best stories on Medium — and support writers while you’re at it. Just $5/month. Upgrade