Worm Watch Lab Talk

What is the red dot?

  • kosmala by kosmala

    What is the red dot? What does it do?

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  • aexbrown by aexbrown scientist

    The red dot marks the side of the worm where we think the vulva is. Worms actually crawl with either their left or right side touching the surface so their "front" and "back" (ventral and dorsal) are visible in the video. The red dot let's us keep track of that.

    The worm will only lay eggs from its ventral side (where the vulva is), but when watching videos you should look at both sides because we don't always get the red dot right!

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  • RedTrev by RedTrev

    I've seen an egg come from a point midway between the red and green dots. Is this possible, or is it just my eyes playing tricks on me?

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  • aexbrown by aexbrown scientist

    Midway between the dots would be extremely unlikely (I've never seen it). Feel free to tag the video if you're unsure so that others can have a look. It could be that the egg was laid around the middle and it was obscured in the bacterial lawn until the worm moved or it could be a disturbance in the bacterial lawn caused by the worm moving (sometimes that can look like an egg).

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  • RedTrev by RedTrev

    You're probably right. Since that one, I've only seen eggs come out towards the posterior from the red dot, never the anterior. And then only by a small margin and not 25% of the total worm length.

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  • RedTrev by RedTrev in response to aexbrown's comment.

    "... we don't always get the red dot right!"

    Yep - here's one that pops out on the other side: http://talk.wormwatchlab.org/#/subjects/AWS000076o

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