The pelican eel is very different in appearance from typical eels. It lacks pelvic fins, swim bladders, and scales. Its muscle segments have a "V-shape", while other fish have "W-shaped" muscle segments. The pelican eel has an aglomerular kidney that is thought to have a role in maintaining the gelatinous substance filling the "lymphatic spaces" that are found around the vertebrae. It has been hypothesized that these gelatinous substance filled "lymphatic spaces" could function in a similar way to a swim bladder. Unlike many other deep sea creatures, it has very small eyes. It is believed that the eyes evolved to detect faint traces of light rather than form images. The pelican eel also has a very long, whip-like tail. Specimens that have been brought to the surface in fishing nets have been known to have their long tails tied into several knots.