A free diver has captured footage of what is believed to be a massive lion's mane jellyfish off the coast of Pembrokeshire, Wales. Iestyn Morgan was swimming near Trefin Beach when he encountered the creature, whose tentacles were so extensive they extended beyond his range of visibility.
Morgan initially mistook the jellyfish for a smaller, native compass jellyfish but quickly realized its immense size. He described the main body of the jellyfish as being "the length of a bus or small train."
The lion's mane jellyfish (Cyanea capillata) is known for its long, flowing tentacles, which can grow up to 3 meters (9 feet 8 inches) in length. However, its tentacles, used for catching prey, can extend significantly further, reaching between 30 to 36.5 meters (98 feet 4 inches to 119 feet 8 inches), making it one of the longest animals on Earth.
Marine biologist Dr. Cathy Lucas from the University of Southampton confirmed that the video footage showcased the jellyfish's remarkable length. She noted that the tentacles are often so fine and long that they can be difficult to see. During fieldwork in Scotland, divers would sometimes encounter stinging tentacle fragments even when no jellyfish were visibly present.
While the sting from a lion's mane jellyfish is described as "nasty" and the worst found in the UK, it is not considered dangerous. The creature's name is derived from its appearance, with its long tentacles resembling a lion's mane, and it possesses "all the beauty and bite of a lion."
Morgan's initiative aims to make Welsh aquatic life more accessible for public viewing.