The mysterious Pyrosomatidae in the class Thaliacea (Urochordata)
Pyrosomes, grouped in the genus Pyrosoma, are free-floating colonial tunicates. They usually live in the upper layers of the open ocean in warm seas, although some may be found at greater depths. Colonies made up of hundreds to thousands of individuals form the cylindrical or cone-shaped pyrosomes, also known as zooids. Such colonial animals range in size from less than one centimeter to several metres in length (commonly less than 4 cm but can reach 4 meters). They are commonly called "sea pickles."
Pyrosomatida colonies, from the Greek "fire bodies", are invading the Pacific Ocean, right in front of the Oregon coast. They may look like jellyfish, but out of the water they retain their cylindrical shape.
Their biology and ecology is still largely unknown. Their classification is also debated by scientists, who are also puzzled by their sudden massive proliferation in a sea. Probably triggered by several years of temperatures above the norm.
Such an invasion had never been recorded previously. And their presence is literally illuminating the ocean. Yes, because these mysterious organisms (innocuous for human beings) have a transparent and luminescent body, due to the presence of bacteria that illuminate them in a way that could resemble the mechanism used by fireflies (just a guess - I have no idea if similar enzymes are involved in this case).
The light normally emitted by Pyrosomatida is yellowish. But if the colony is touched or felt threatened in some way, it suddenly changes color, creating shades that range from white to blue, from green to red, so brilliant and intermittent to be seen even from long distances.
On the behavior of these bizarre "incandescent" colonies, there are several theories. Scientists, for example, believe that bioluminescence can be a method of communication, to attract plankton or even scare predators.
Each colony is made up of clones that work together to move and filter the water to catch the plankton for feeding. They have been known for centuries but have always been so rare and mysterious that they were considered the unicorns of the sea. At least until this spring, when millions and millions of luminous tubes began to float in fishermen's networks and spin along the coastline between Alaska and Oregon.
The question is:
Why here and why now?