Sea Cucumbers
Order: Dendrochirotida

Sea cucumbers are echinoderms with elongated, spiny-skinned bodies. They live at the bottom of the lower Chesapeake Bay’s deep, salty waters.

The pale sea cucumber is white or pale yellow with five distinct rows of tube feet. (Alan Cressler/Flickr)

Appearance

Two species of sea cucumbers can be found in the Chesapeake Bay:

  • The hairy or common sea cucumber, Sclerodactyla briareus
  • The pale sea cucumber, Cucumaria pulcherrima

Sea cucumbers have elongated, cucumber-like bodies that are thickest in the middle. They have distinct front and rear ends, with 10 finger-like tentacles around their mouth. The hairy sea cucumber is dull brown and grows four to five inches long. Its fat, rounded body is covered with tube feet. The pale sea cucumber is white or pale yellow and grows one to two inches long. Its tube feet are arranged in five distinct rows.

Feeding

The sea cucumber uses its tentacles to capture plankton and other tiny particles, then sweeps the food into its mouth.

Reproduction and Life Cycle

Sea cucumbers spawn by releasing eggs and sperm into the water, where the eggs are fertilized. During spawning, sea cucumbers develop a cobra-like appearance, with their front end raised up from the bottom. Larvae spend several weeks floating in the water.

They eventually settle to the bottom and morph into tiny juveniles. Juveniles take several years to grow to their adult size. Sea cucumbers can live up to eight years.

Did You Know?

  • Sea cucumbers are related to sea stars: both are echinoderms, which means “spiny-skinned.” All echinoderms have five-part radial symmetry.
  • If a sea cucumber loses a tentacle, it can grow a new one in about three weeks.
  • If you pick up or bother a sea cucumber, it will squirt water from its rear hole, and it may even eject its innards. This is a defense mechanism that sea cucumbers use to protect themselves from predators.

Sources and Additional Information

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Invertebrates Streams & Rivers