Paraleptopentacta elongata is a slender, greyish-brown sea cucumber with a U-shaped, or sometimes S-shaped body, reaching a maximum length of about 10 cm (4 in).

The cuticle is leathery, stiffened by numerous smooth ossicles, small irregular perforated plates which form part of the body wall.

[3] Paraleptopentacta elongata is considered as a suspension feeder by some sources, consuming diatoms, single-cell algae and organic particles, as well as zooplankton, such as copepods, ostracods, protozoans, nematodes, jellyfish and larvae.

[4] However, another work tends to prove that Paraleptopentacta elongata is a deposit feeder, living burrowed in sediment with only a short portion of its aboral end protruding.

In this work, the author reports a two weeks period during which none of the observed specimens emerged from the substratum but they produced faecal pellets near the burrow openings, indicating the feeding occurs beneath the sediment.