Answer:
This is most likely a segmented worm
Explanation:
*Segmented worms have long tube - like bodies that are divided into segments.
*They are the simplest organism with a true nervous system and blood contained in vessels.
*They have a long digestive tube that runs down the length of the worms inner body.
* and they can take in disolved oxygen from the water through their skin
I hope I helped someone :)