Malta’s underwater world never fails to amaze! Marine biologist Professor Alan Deidun recently shared a stunning video, captured by David Agius, showing the graceful undulations of a fan worm clinging to the hull of a wreck in Maltese waters.
The worm, the professor shares, is suspected to be Sabella spallanzanii, also known as the Mediterranean Fan Worm, European Fan Worm, Feather Duster Worm, or Pencil Worm. Using its spiral crown of tentacles, the worm scoops up plankton from the water column – but don’t be fooled by its calm movements! When disturbed, it retreats swiftly into its stiff, sandy tube, cleverly built from hardened mucus.
Fan worms can grow anywhere between 9 to 40cm, often reaching their largest size in deeper waters. Their feeding tentacles can form striking patterns and banded colours, from orange, purple and white to uniform pale grey. Over time, epiphytic organisms often settle on the tubes, giving them a textured, wrinkled look near the base.
As filter feeders, Mediterranean Fan Worms dine on bacteria, phytoplankton, zooplankton, and tiny organic particles. Interestingly, individual worms are either male or female, with large females capable of producing upwards of 50,000 eggs during breeding season. After about two weeks as planktonic larvae, they settle on the seabed and complete metamorphosis around ten days later.
This video is a rare glimpse into the delicate yet fascinating life of a creature often overlooked beneath Malta’s waves. Keep your eyes open next time you explore a wreck – the sea is full of hidden wonders!
Have you ever spotted one underwater?