Living sailors

The big question: Does the direction of the Velella velella sail drive global patterns in their distribution?

For thousands of years, humans have been delighted and surprised by strange blue jellies washing up on shore. These harmless animals, called by-the-wind sailors (or Velella velella), are normally found in the open ocean far from shore, but occasionally, when the wind blows just right, they drift ashore and are stranded on land by the thousands. Over 100 years ago, scientists began documenting the direction that the sails point. Because the animals are oblong we can determine which way their sail points by simply looking at them from above Left-handed animals have a sail that tilts from left to right (if you imagine a clock face, it has a sail with one end pointing at 11, and the other end at 5). Right-handed sails tilt from right to left (on our clock face the sail points from 1 to 7). Some scientists think the left-handed animals are more common in the Northern Hemisphere because they are blown toward shore, while others think the left-handed animals are more common in western waters. Equipped with images of thousands of Living Sailors, and with your help, we will map the distribution of left- and right-handed sailors spanning every ocean basin and test those predictions.

How can well tell left from right?

It can help to think of the hands on a clock... Since sailors are oblong, when you position a sailor lengthwise (as pictured), a lefty will have their sail positioned at 11 and 5, righty will have their sail positioned at 1 and 7.

Rotation does not matter

Once a lefty, always a lefty!

The curious case of upside-down sailors

Be sure to "flip" your classification if you see an upside-down sailor

The big picture

We can tell left from right, up from down, now what?

Does the direction of the sail "sort" the sailors into different ocean basins? Although many high-profile papers have been published on this topic, no one could answer the question because they did not have access to large global data sets. Now, thanks to iNaturalist and the GO-SEA team, we have over 7000 observations of by-the-wind sailors. You can help solve this mystery! Join our project and help us build a map of by-the-wind sailor jellies.