Although the sunfish scarcity continues, the recent stormy seas have washed up a variety of intriguing creatures as the waves cough up their flotsam onto the beaches. As I walked the beaches in search of sunfish harnesses and other potentially interesting finds, it appeared that the pebbles were littered with tiny pieces of soft plastic, like shredded shopping bags. Among the plastic bottles and tumbled logs, the beaches around Santa Margherita have been invaded by a thousand strong flotilla of ‘by-the-wind-sailors’ or Velella velella.
* I appreciate that Velella Flotilla sounds like something you might have as a snack with your morning coffee but I couldn’t resist. “Would you like a Velella Flotilla with that?”
Thousands of Velella’s in the breaking waves (photo credit Lawrence Eagling see more on his amazing photography website: eaglingphotography.co.uk).
These tiny creatures are remarkable for many reasons! Firstly, their shape means that they float on the sea surface, with tiny tendrils trailing the water for plankton like little fishing nets. However, rather than waste precious energy by swimming or pulsing, these animals have evolved to travel the high seas like the explorers of old: using wind power! The central triangle section acts as a sail, driving the Velella around the ocean. Intriguingly, these creatures come in two forms; one right-handed and one left-handed, with sails set to differing angles. The theory behind this is that if the prevailing wind direction drives all the right-handed Velella’s to strand on beaches, the left-handed population will sail to safety and re-populate.
Due to their gelatinous bodies, these are tiny creatures are often mistaken for jellyfish, however the truth is far more intriguing! They are actually classed as hydroids, (like the Portuguese Man Of War!), which are composed of hundreds of individual creatures, all working together to form a larger centrally functioning “body”. Each individual has a specialised function (from those that work in digestion of prey, to making the sail, to reproduction), but all benefit from the communal actions of the whole. Inside the living tissues, a central structure made of carbonate, acts as a skeleton to keep the boat and sail sections rigid.
Although the floating colony stage is the one most people are more familiar with, however this is just one of many stages in a complex life cycle. The colony will later release tiny medusa (a few mm long) which are the sexual reproducing stage and will release eggs and sperm into the water. The eggs can develop into tiny larvae which later develop into the floating colony again!
Illustrated Velella lifecycle (diagram found at bodegahead.blogspot.it, modification of original by Langstroth and Langstroth 2000)
The recent rough seas here in Italy have driven large numbers of Velellas (usually found in the open oceans of warm temperate and tropical regions) to form huge aggregations, and some of which have been driven ashore. The good news for my research is that ocean sunfishes have been photographed eating Velella’s as a bite sized snack! So fingers crossed for some more sunfish soon 🙂
For video of sunfish chasing down Velella’s check out this link: youtu.be/q2ZgzIlXh8c
This beautiful photo shows exactly what I would love to see! Many thanks again to © Jodi Frediani for her kind permission to borrow this one and for more wonderful photographs check out her website: http://www.jodifrediani.com
Any questions/comments? Found a sunfish? Get in touch!