A worldwide community photographing and learning about wildlife
Fluorescent yellow worms
Rainforest creek stones
Yes, I know it's not an arthropod but Noah doesn't have enough categories.
Took a while to find out, but I reckon it's a Canary Worm - predatory (round) flatworms. Wouldn't normally have found them but the rainforest was in a drought so they had gathered on stones in the creek.