#just realized that like 90% of original posts/additions on my blog are bug related and usually linked to this specific bug blog

[myceliumromance]

It's the cuticula!

"The annelid cuticle is unpigmented and the iridescence of many annelids is caused by interference effects."

From the book chapter linked, sadly I do not have access to the full version. Frankly this was just the first result that confirmed what I already remembered from my zoology seminar - we dissected earthworms which did not have any residual mucus on them (alcohol collection), and it was the skin itself that was strikingly shiny and iridescent :)

hi, just found your blog<3

do you know why the (earth)worm’s shiny on the right end? is it iridescence or just weird lighting because I took the photo w flash on?

It's iridescence and it's normal on earthworms, but I'm not sure if the light refraction is caused by structures in their skin or in the mucus covering their body or some secret third thing.

You can also see it on this giant earthworm here!