[2] This species is specifically found in the deep-sea in cold waters like the Antarctic Ocean.

[3] The scale worms have been believed to be descendants of a different species that invaded the deep-sea millions of years ago.

[4] They have also been found in chemosynthesis-based habitats, like hydrothermal vents, anchialine caves, cold seeps, and more.

[13] The retractable proboscis consists of a pair of large jaws used for grasping prey while hunting.

[15] When the scale worms stop swimming, they mostly sink to the floor of the ocean while some others may remain suspended in the water column.

[15] They swim by the antagonistic contraction of the longitudinal body muscles and the movement of parapodia.

[15] Eulagisca gigantea most likely uses a similar respiratory, circulatory, nervous, and digestive system as most marine Annelids.

The nervous system of E. gigantea is likely a centralized cerebral ganglion in the prostomium with a ladder of nerves through the rest of the body.

[17] After the larvae goes through metamorphosis, the juvenile scale worms start using their proboscis with jaws to feed.