Chinese are eating Cyanobacteria as a prosperous symbol

Oyster mushroom and Fat Choi

Fat choi, which has the same sound in chinese as "hair vegetable", can also have the same sound in chinese "prosperity", and therefore, it is a popular Chinese New Year dish to usher in a year of wealth and prosperity.

Although it is known as a sea moss, it's not exactly a fungi/algae, it's made of a phylum of bacteria, which can undergo photosynthesis, they are the only known prokaryotes to be able to do that.

They are called cyanobacterium due to their color, cyan.

Their ability to produce oxygen through photosynthesis have thought to contribute to the Great Oxygenation Event, and also the "Rusting of the Earth", cyanobacterium in general, not just Fat Choi.

Cyanobacterium gets really little credit for producing almost half of Earth's oxygen, with trees and land greens getting most of it.

Cyanobacterium in general aren't edible, Fat Choi are slightly less damaging, however, like most of the species, still produces a toxin called beta-N-methylamino-L-alanine (BMAA), an amino acid that could affect the normal functions of nerve cells and is linked to degenerative diseases such as ALS, Alzheimer's, Parkinsons's and dementia, people living within half a mile of the cyanobacterially contaminated lake have a higher likelihood up to 2.3 times to develop ALS than the rest of the population, therefore it is not advised to eat a large amount of them.

Luckily, most Chinese dishes only offers a small amount of the phylum, therefore, it's safe to eat it as a Chinese New Year prosperous symbol.

Fat Choi has only a vague grassy taste of its own, but is supposed to absorb flavors from whatever it is cooked in.

In China, it is falsely popularly thought that eating Fat Choi may have some nutritional benefits, but laboratory analysis at the Chinese University of Hong Kong found it to be entirely indigestible and of no nutritional value.

Which is, personally a huge let down for me. It looks delicious, but I wouldn't really wanna eat something of zero health  benefits and also potentially health damaging.

It is harvested in the Gobi Desert and the Qinghai Plateau, but harvesting has been restricted due to resulting erosion.

QingHai - Tibet Plateu (can't find one for Ghobi)

Due to increasing cost, sellers are known to adulterate the product. Real Fat Choy is dark green - the adulterant ones made from starch, are usually black. Real Fat Choy will stand up to over 30 minutes of simmering, but adulterant strands will disintegrate.

The photo specimen skein was purchased from a large Asian market in Los Angeles and smelled like drying grass. Individual hairs are no thicker than human hairs, but are actually made up of many microscopic strands of cyanobacteria.

Another type of cyanobacteria are Spirulina, unlike Fat Choi, spirulina have actually got an array of nutritional content, beneficial ones of course.