Stichopodidae Family of Spiky Sea Cucumbers

Three Spiky Sea Cucumbers of the Stichopodidae Family can be found in this website:

Phylogeny: Spiky Sea Cucumbers of the Stichopodidae Family, like sea stars and sea urchins are in the phylum Echinodermata. They are in the subphylum Echinozoa, the class Holothuroidea, the subclass Actinopoda and the order Synallactida. The Stichopodidae Family is one of three families in this order. The Stichopodidae Family contains ten genera and thirty-five species. The name Stichopodidae comes from the Greek words meaning “row feet” or “line feet”. This refers to the rows of tube feet found on these animals.

Morphology: Spiky Sea Cucumbers, as Echinoderms (meaning spiny skin) are characterized by a larval stage with bilateral symmetry and an adult stage with radial (5-rayed) symmetry. They are unsegmented and cucumber-shaped. They have a water vascular system, tube feet, and a complete digestive system, but they lack eyes, a head, nervous system, or excretory system. They have a soft body wall and twenty branched tentacles around their mouth, utilized to capture food. Spiky Sea Cucumbers have a flattened ventral surface and a square or angular cross section. They have larger, fleshy, cone-shaped projections on their bodies, which give rise to their common name Spiky, mixed in with much smaller papillae. Spiky Sea Cucumbers tend to be medium to large in size, with some having a maximum of 2 m (6 feet 7 inches) in length.

Habitat and Distribution: Spiky Sea Cucumbers reside on bedrock, mud, rock, and sand, habitats from the intertidal zone to depths exceeding 1,700 m (5,576 feet). The majority are found in shallow water. They are generally found in more protected areas, where water movement will not sweep their food away. Spiky Sea Cucumbers are found worldwide in temperate to tropical seas. At least five species from this family are found in Mexican waters.

Reproduction: Spiky Sea Cucumbers are gonochoric (either male or female for life). They reproduce sexually through broadcast spawning with external fertilization. The fertilized eggs develop into planktonic larvae. They can also reproduce asexually through transverse fission.

Ecosystem Roles: Spiky Sea Cucumbers are depositional feeders that crawl along the bottom, using their sticky tentacles to collect detritus and other organic matter, such as bacteria and fungus. This method of feeding redistributes sediment, and therefore contributes to the general ecology. Spiky Sea Cucumbers lack the Cuvierian organs that release a sticky substance of some other sea cucumber families. They are preyed upon by fish, marine mammals, and starfish. They do have the ability to auto-eviscerate their internal organs to distract potential predators. Some members of the family have an annual cycle of auto-eviscerating their digestive tract and gonads to remove sediment build up caused by their feeding process. They regrow these organs in a matter of weeks.