Osmotic eel
The osmotic eel was a small aquatic lifeform resembling a starfish that was useful in medicine for cleaning and healing wounds.

Doctor Phlox kept an osmotic eel on board during his assignment to , and it could often be seen in the starship's sickbay, in a  of water. During their first mission in April of 2151, it was used to cauterize Captain Archer's leg wound. ()

In 2152, following the injury of several crewmembers, Phlox told one officer he would have to wait in line for the eel to cauterize his wound, noting that the creature was "getting quite a workout today". ()

He offered to give it to E'Lis, a medical practitioner at a deuterium mining colony later that year, but she joked she wouldn't know what to feed it. Phlox then explained to E'Lis that the eel's feeding needs were relatively modest, as it only required a nutrient broth every three or four days. He further noted that while it was working, it required its nutrient broth even less, as it usually ingested a little blood while healing an injured artery. ()

Hoshi Sato fed Phlox's osmotic eel with Vulcan root leaf in 2153. ()

The next year, Phlox was looking at the osmotic eel in its tank when Commander Tucker entered sickbay. ()

In 2154, the eel was used to help remove Xindi neural parasites that a group of Xindi-Reptilians had injected into Hoshi Sato to force her compliance. ()

Later that year, Phlox told Hoshi Sato that his osmotic eel was ill and that he should remain on board Enterprise until the animal was feeling better. This, however, was an excuse for the fact that Phlox didn't want to visit Earth with Sato that evening. ()

Appendices

Background information
The fictional use of osmotic eels for medical purposes echoes the real-world application of .

When it came time to design the osmotic eel, the task fell to Makeup Supervisor Michael Westmore, because the eel was supposed to be alive. He later noted, "They just said, 'You do the leech!" Westmore produced numerous sketches, from which the producers chose the final, starfish-shaped design. The prop of the creature was then manufactured in the makeup lab, again due to it being supposedly alive. The model was created complete with hairs but required an extra small detail for its on-screen appearance. "We had it all goo'd up; there was stringy goo on the bottom, so when it was picked up those little stringy things would hang down," Westmore explained. Between its appearances in , the model was placed into his desk drawer. () 

The prop model was later sold off on the It's A Wrap! sale and auction on eBay. 

In , Phlox refers to the eel as a "he", while in , he calls it a "she". This may suggest that these are not the same eels, or that they have the ability to change their sex.

External link
 
de:Osmotischer Aal
Animals