Leptopentacta elongata is a burrowing sea cucumber, which lives in U-shaped burrows. Its cylindrical body tapers at both ends with ten white, bushy tentacles at one end and the anus at the other end both protruding out into the water column. It has five distinct double rows of tube feet. The skin is thick and tough. Its narrow body may reach up to 15 cm in length and is brown to off-white in colour.

A long tapering body and small white sparsely-branched tentacles are the distinctive features of this sea cucumber. The thin body has a long pointed tail and often lies curved in the sediment in a U-shape. The brown body bears five distinct rows of tube-feet. There are spicules in three layers,large irregular flat plates with numerous holes, smaller round plates with holes and small basket-shaped spicules nearest the surface. Length about 10cm, diameter 1cm or less. No other species have the characteristically shaped body.

This species can be found in the waters of the Mediterranean and the Atlantic from Norway to Morocco. (Grzimek 1972)

Biogeographic Regions: atlantic ocean (Native ); mediterranean sea (Native )

Subtidal to 100 m depth, burrowing iin muddy sediments, with both ends curved upwards; western coasts of the British Isles, round the north of Scotland and down the northeast coast

British Isles, European waters (ERMS scope), Greek Exclusive Economic Zone, Irish Exclusive economic Zone, North East Atlantic, North Scotland, North West Scotland, United Kingdom Exclusive Economic Zone

Found all round the British Isles.

This species has an elongated body that is usually U-shaped and resembles the shape and size of the vegetable, cucumber, where it gets its name. It has a tube-shaped ventral surface with 5 rows of tube feet that extend the entire length of the body. It does not have arms. (Banister and Campbell 1985.) The dorsal surface is covered with stiff, conical projections that are brownish or gray in color. The body wall is naked with only minutely defined ossicles and is very elastic and leathery in texture. Their mouth is located at the anterior and their anus is located at the posterior. The mouth is surrounded by a ring of simple branched tentacles that are usually retractable when they catch their prey. (Grzimek 1972.) They have a water vascular system that includes a water ring around a proximal pharnyx with 5 radial canals that run the length of the body wall. They are pentameral, or have 5-rayed symmetry with 5 rows of tube feet.(Fisheries and Oceans Canada). They range in size from a few centimeters to 8 inches. (Carson 1955)

This species is strictly marine and can be found in the sand and mud from sea level to 110 meters in the water. (Grzimek 1972.)

Aquatic Biomes: coastal

Depth range based on 42 specimens in 1 taxon.
Water temperature and chemistry ranges based on 5 samples.

Environmental ranges
  Depth range (m): 2 - 127
  Temperature range (°C): 8.393 - 13.257
  Nitrate (umol/L): 0.873 - 11.724
  Salinity (PPS): 34.402 - 38.362
  Oxygen (ml/l): 5.828 - 6.223
  Phosphate (umol/l): 0.031 - 0.812
  Silicate (umol/l): 2.859 - 7.198

Graphical representation

Depth range (m): 2 - 127

Temperature range (°C): 8.393 - 13.257

Nitrate (umol/L): 0.873 - 11.724

Salinity (PPS): 34.402 - 38.362

Oxygen (ml/l): 5.828 - 6.223

Phosphate (umol/l): 0.031 - 0.812

Silicate (umol/l): 2.859 - 7.198
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

Depth range based on 65 specimens in 1 taxon.
Water temperature and chemistry ranges based on 55 samples.

Environmental ranges
  Depth range (m): 0 - 485
  Temperature range (°C): 6.911 - 17.154
  Nitrate (umol/L): 0.296 - 5.787
  Salinity (PPS): 33.548 - 38.547
  Oxygen (ml/l): 5.432 - 6.588
  Phosphate (umol/l): 0.128 - 0.519
  Silicate (umol/l): 1.450 - 4.208

Graphical representation

Depth range (m): 0 - 485

Temperature range (°C): 6.911 - 17.154

Nitrate (umol/L): 0.296 - 5.787

Salinity (PPS): 33.548 - 38.547

Oxygen (ml/l): 5.432 - 6.588

Phosphate (umol/l): 0.128 - 0.519

Silicate (umol/l): 1.450 - 4.208
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

 Leptopentacta elongata is a sublittoral benthic species often found buried in sandy or muddy sediment down to a depth of 70 m.

Lives buried in muddy sand or mud with only the tentacles visible. Can be common in shallow water with Virgularia mirabilis.

They will eat almost anything in range but usually eat plankton and other small microscopic organisms (Stachowitsch 1992). They function like earthworms, ingesting sand and mud along with the plankton and pass it through their bodies (Carson 1955). Some species of sea cucumbers have annual periods of dormancy where they eat nothing at all and only eat when the water has reached a certain temperature. During these rest periods that usually start in October or November, they display atrophy of their internal organs. New internal organ are then regenerated when they are ready to eat again, about 6 weeks later (Grzimek 1972).

Doliolatia larva

They mainly reproduce by sexual reproduction and have only one gonad which is a cluster or tuft of closed tubules. Spawning lasts about 30 minutes and is done directly in the surrounding water usually in late afternoon. The male gamete is released first into the water then the females lay eggs. Gamete-release is triggered by the presence of pheromones. Fertilization thus takes place in the water, then the fertilized egg either sinks to the bottom or rises to the water surface. (Grzimek 1972.)

All fishermen must possess a special license to fish sea cucumbers and some coastal areas have closed fishing of sea cucumbers and restricted it to certain times of the year in order to protect the species. (Stutz 1995.)

US Federal List: no special status

CITES: no special status

No major negative effects known, but if sewage is dumped into waters it may settle all of the way on the ocean floor. Such contaminates may be ingested by the sea cucumber and eventually affect organisms higher on the food chain. (Detjen 1993.)

Sea cucumbers can be used in home saltwater aquariums to keep them clean of plankton and other unwanted small organisms.

Sea cucumbers are also important to the fishing industry, especially pepineros (sea cucumber fishermen) because they are a prized ingredient in Asian cuisine.

Sea cucumbers are first gutted, their body wall dried, and then made into a soup (Detjen 1993).

In addition, scientists say that studying the methods that sea cucumbers use to deal with infections may yield information about peritonitis in humans. (Stutz 1995.)