So the other day, I was watching this beautiful Six-lined Ribbon Worm (Tubulanus sexlineatus). It was gliding over a patch of orange sea squirts.
Along with being curious about what the ribbon worm was up to, I started wondering how long it was. So I scanned left:
And then I scanned to the left some more:
And then I scanned to the left some more, and realized that I was looking at a very long ribbon worm. This might be hard, but can you find additional lengths of the ribbon worm behind the main section? [You can click on the image below for a slightly larger version.]
Given the scale of the photo, I know this is challenging. Here are some arrows to help you (the rightmost arrow is the head and the leftmost arrow is the last part of the ribbon worm that I could find):
And here's a close-up of the lower left corner of the photo to make it easier to spot the left-hand sections of the ribbon worm:
I estimated that the portions of this Six-lined Ribbon Worm that I could see, from the head to where I could no longer follow it, added up to a length of ~50 cm (~20 inches). It turns out that this species of nemertean is described as being ~20 cm long, but it can stretch to lengths of over 1 meter!
And since you stayed with me, below is a bonus shot — just enjoying the patterning of the ribbon worm against a colorful backdrop:
P.S. If you're interested, there are some wonderful microscope images of this species in the post called "All lined up" on 20 March 2015.