Velella velella, commonly known as “By-the-wind sailors,” are a frequent sight on coastlines, particularly after periods of strong winds or storms. Their distinctive appearance often sparks both curiosity and questions about their safety. While they might resemble jellyfish, these unique creatures have characteristics that set them apart.
Understanding Velella Velella
Velella velella are not true jellyfish, but rather free-floating hydrozoans, which are marine animals related to jellyfish, sea anemones, and corals. They feature a flat, oval, deep blue to purple disc, measuring about 1.5 to 4 inches (3 to 10 cm) in length. A prominent, clear, triangular “sail” projects diagonally from their body, allowing them to catch the wind and drift across the ocean surface.
These organisms are pelagic, meaning they inhabit the open ocean surface, with their movement primarily dictated by wind patterns. Short, blue tentacles dangle beneath their float, containing stinging cells called nematocysts, which they use to capture small planktonic organisms like copepods and fish eggs for food.
Assessing Their Threat to Humans
Like many cnidarians, Velella velella possess nematocysts on their tentacles. However, these stinging cells are too small or too weak to effectively penetrate human skin. Contact with Velella velella is rarely harmful to humans.
Any reaction to touching them is mild, often manifesting as a slight tingle, itching, or minor redness, particularly for individuals with sensitive skin. They are harmless and not dangerous to humans. The risk of a significant reaction is very low, unlike encounters with more potent marine creatures such as the Portuguese man o’ war, to which Velella velella are distantly related.
Encountering Velella Velella
When Velella velella wash ashore, often in large numbers due to specific wind conditions, there is no cause for alarm. While they are benign, it is advisable to avoid intentionally handling them.
If contact occurs, especially with sensitive areas like the face or eyes, mild irritation could result. After any accidental contact, washing hands thoroughly with soap and water is recommended. Dog owners should also be aware that while Velella velella are not considered dangerous to humans, their small stingers can cause irritation to a dog’s mouth and stomach if ingested, potentially leading to gastrointestinal distress.