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Wednesday, May 11, 2016


Finally!  I can't tell you how many By-the-wind Sailors (Velella velella) I've looked at...and I had yet to find a right-handed Velella, until tonight (11 May 2016).

Velella is known to have two different morphologies.  Left-handed Velella have the sail angled across the body from the upper left to the lower right.  The majority of Velella observed in the Bodega Bay area are left-handed.  

Right-handed Velella have the sail angled in the opposite direction, i.e., across the body from the upper right to the lower left.  The Velella pictured above is right-handed.

For comparison, here's a more typical left-handed Velella (on the left) next to the less common right-handed Velella (on the right).  Compare the angles of the sails:

There's been a long-standing question regarding the significance of having a left-handed or right-handed sail.  And people have wondered whether the abundance of the two different forms is related to being in the northern vs. southern hemispheres, or in the eastern vs. western sides of an ocean.  As far as I know, the significance of "handedness" in Velella has not been well studied and remains a mystery.  

If you come across a right-handed Velella, I'd love to hear about it!


Kristin Aquilino said...


John W. Wall said...

I would never even have thought to look for handedness in Velella, but you can bet I will think of nothing else when I see them next. ;)

Jackie Sones said...

Yeah, I know what you mean. There have been lots of Velella around during the last few years. I don't look for handedness all of the time, but I casually watch to see if I can spot a right-handed one -- it's too intriguing not to. :)

Dean Sevold said...

I have looked at pictures of velella from Australia and they seem to be right handed.https://bie.ala.org.au/species/urn:lsid:biodiversity.org.au:afd.taxon:c4682036-0907-42e4-a2f3-6db0f4b9ce41#gallery