Accordion Sea Cucumber, Euapta godeffroyi

Accordion Sea Cucumber, Euapta godeffroyi. Underwater photographs taken in the Revillagigedo Islands, November 2023. Photographs courtesy of Aaron Woodrow, Juneau, Alaska. Photographs and identifications courtesy of Aaron Woodrow, Juneau, Alaska.

Phylogeny: The Accordion Sea Cucumber, Euapta godeffroyi (Semper, 1868), is a member of the Synaptidae Family of Sea Cucumbers. The Euapta Genus is one of nineteen genera in the Synaptidae Family, and there are five species in the Euapta Genus. They are also known as Godeffroy’s Worm Cucumber, the Lion’s Paw Sea Cucumber and the Sticky Snake (named for their ability to attached to human skin when handled), and in Mexico as Pepino de Mar Acordeón.

Morphology: The Accordion Sea Cucumber has a long, slender, soft, flexible body with a body surface with several rows of pouch-like formations, giving the appearance of an ear of corn. a “bubbly” appearance, particularly when contracted. The spicules (microscopic calcareous structures that project through the skin) are a mixture of anchors and perforated plates with large holes. They fragment easily. The mouth is terminal and is encircled with fifteen feather-like tentacles. The skeletal components of the body wall are mainly anchors with tiny ramifications at the base of the central axis and anchor plates with big perforations and miliary granules. Two more types of ossicles were observed: one anchor-shaped ossicle with a smooth and pointing end (an early stage of the anchors) and another rod-shaped with forked branched ends. The anchors and plates were present in both the body wall and the tentacles while the rods were only observed in the oral tentacles. They lack tube feet. They have a grayish-brown body with a wide brown line with highly visible yellow margin. Their tentacles are creamy in color and pinnated (feather like). They reach a maximum of 80 cm (20 inches) in length and 3.0 cm (1.2 inches) in diameter and vary significantly in length as they have the ability extend their bodies to four times resting length and can contract their bodies as a defense mechanism.

Habitat and Distribution: The Accordion Sea Cucumber is found in rocky and patch reefs and under rocks at depths up to 80 m (260 feet). They have a wide global distribution and in Mexico they are found in all oceanic waters of the Pacific Ocean with the exception that they are absent from the northern half of the Sea of Cortez and along the west coast of the Baja Peninsula.

Diet: The Accordion Sea Cucumber a nocturnal deposit feeder. They take shelter during daylight hours and emerge at night between coral rubble and loosely dispersed Pocillopora Sp. coral colonies. They are a suspension feeder that utilizes its anchor spicules for adhesion and filtering organic particles and planktons from the surrounding sea water. They consume several times its body weight each day.

Predators: The predation of the Accordion Sea Cucumber has not been doucmented.

Reproduction: The Accordion Sea Cucumber occurs with lunar synchronization. It is gonochoric with separate sexes being male or female. They possess only a single gonad consisting of a cluster of small tubes. Reproduction occurs via external fertilization with thousands of sperm and egg gametes released directly in the open ocean. The embryos evolve into transparent Auricularia Larva that feed on microalgae and the juveniles settle onto the reef substrate.

Ecosystem Interactions: The Accordion Sea Cucumber has a commensal relationship with the Scale Worm, Gastrolepidia clavigera, the Imperial Shrimp, Periclimenes imperator and various Pearlfishes from the Carapidae Family.

Human Interactions: From a conservation perspective the Accordion Sea Cucumber has not been formally evaluated. They have a wide global distribution and are common and should be considered to be of Least Concern. They do not survive in captivity and are not utilized by the aquarium trade.

Synonyms: Euapta godefroyii and Synapta godeffroyi