"Bizarre!" is how the city ecologists in Utrecht, The Netherlands describe this bright orange sac discovered attached to a floating island in one of the city's canals.
It turns out that the "large slippery thing," as described by the ecologists, is actually a colony of tiny Bryozoans.
Often called "moss animals," Bryozoans are small, aquatic, colonial invertebrates found in both marine and freshwater environments. They're typically sessile (non-moving) and live attached to surfaces like rocks, seaweeds, and other underwater structures—hence their location in the Utrecht canal. Their colonies often resemble coral—or in this case, a ball of lava.
From AD.nl (translated via Google):
The bag was discovered by volunteers and has been placed back under the island. After all, the animals do not harm anyone in the water, says Nijs. 'And it is the first time that they have been discovered here. So it is a very special story.''
Also striking: the colonies die off in the fall. Washed-up remains can then cause odor nuisance.
Previously:
• A handsome and rare deep sea creature washed up onto the shores of La Jolla this August
• Mysterious metal sphere washes up on Japanese beach, baffles authorities
• What is this strange metal artifact that washed up in North Carolina?