| Euapta lappa | |
|---|---|
 | |
| Anterior end of beaded sea cucumber | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Echinodermata |
| Class: | Holothuroidea |
| Order: | Apodida |
| Family: | Synaptidae |
| Genus: | Euapta |
| Species: | E. lappa |
| Binomial name | |
| Euapta lappa (J. Müller, 1850) [1] | |
Euapta lappa, the beaded sea cucumber, is a species of sea cucumbers in the family Synaptidae in the phylum Echinodermata. It is found on coral reefs in the Caribbean region.
In appearance, the beaded sea cucumber resembles a long worm rather than a sea cucumber. It can reach up to a metre (yard) in length and has a diameter of up to 4 cm (1.6 in). It lengthens and shortens repeatedly and when disturbed, the normally flaccid body retracts vigorously to a fraction of its original length. It has no internal respiratory tree, nor does it have tube feet, and the body surface is covered by rounded ridges. The skeletal structure consists of many tiny calcareous plates embedded in the cuticle. Little hooks project from these ossicles and make the body feel sticky to the touch. At the anterior (front) of the animal there is a ring of fifteen branched feeding tentacles. The body colour is pale brown or grey, often with white flecks or darker, longitudinal streaks and transverse banding. [2] [3] [4]
The beaded sea cucumber is found in the Caribbean Sea, the Bahamas, Jamaica, Cuba, the Gulf of Mexico, Mexico, Costa Rica, Panama and the Lesser Antilles. It is also known from the Canary Islands. [1] It is found on reefs at depths down to about 30 metres (98 ft), hiding during the day among boulders and coral debris. [3]
The beaded sea cucumber is a detritivore. It uses its tentacles to sift through sediment on the seabed, pushing it into its mouth aperture. The organic material in the sediment is digested and the inorganic matter is expelled through the cloacal vent. [2]
Locomotion takes place as a result of contraction of muscles in the body wall. These consist of both longitudinal bands of muscle and continuous circular bands forming a tube. The contraction of different regions of musculature enables the sea cucumber to move around as waves of peristalsis pass along the body. [4] The ossicles prevent slipping by providing friction with the substrate. In an aquarium, this sea cucumber can climb the vertical glass side by using peristalsis in this way, with the only point of attachment being the tentacles. [4]
An echinoderm is any deuterostomal animal of the phylum Echinodermata, which includes starfish, brittle stars, sea urchins, sand dollars and sea cucumbers, as well as the sessile sea lilies or "stone lilies". While bilaterally symmetrical as larvae, as adults echinoderms are recognisable by their usually five-pointed radial symmetry, and are found on the sea bed at every ocean depth from the intertidal zone to the abyssal zone. The phylum contains about 7,600 living species, making it the second-largest group of deuterostomes after the chordates, as well as the largest marine-only phylum. The first definitive echinoderms appeared near the start of the Cambrian.
Sea cucumbers are echinoderms from the class Holothuroidea. They are marine animals with a leathery skin and an elongated body containing a single, branched gonad. They are found on the sea floor worldwide. The number of known holothurian species worldwide is about 1,786, with the greatest number being in the Asia-Pacific region. Many of these are gathered for human consumption and some species are cultivated in aquaculture systems. The harvested product is variously referred to as trepang, namako, bêche-de-mer, or balate. Sea cucumbers serve a useful role in the marine ecosystem as they help recycle nutrients, breaking down detritus and other organic matter, after which bacteria can continue the decomposition process.
Anthozoa is a subphylum of marine invertebrates which includes sessile cnidarians such as the sea anemones, stony corals, soft corals and sea pens. Adult anthozoans are almost all attached to the seabed, while their larvae can disperse as planktons. The basic unit of the adult is the polyp; this consists of a cylindrical column topped by a disc with a central mouth surrounded by tentacles. Sea anemones are mostly solitary, but the majority of corals are colonial, being formed by the budding of new polyps from an original, founding individual. Colonies are strengthened by calcium carbonate and other materials and take various massive, plate-like, bushy or leafy forms.
Apodida is an order of littoral to deep-sea, largely infaunal holothurians, sea cucumbers. This order comprises three families, 32 genera and about 270 known species, called apodids, "without feet".
Holothuriida is an order of sea cucumbers. Taxa within the order Holothuriida were previously classified in the order Aspidochirotida, which was determined to be polyphyletic in 2017. Some taxa were also reclassified into the clades Synallactida and Persiculida.
Sea anemones are a group of predatory marine invertebrates constituting the order Actiniaria. Because of their colourful appearance, they are named after the Anemone, a terrestrial flowering plant. Sea anemones are classified in the phylum Cnidaria, class Anthozoa, subclass Hexacorallia. As cnidarians, sea anemones are related to corals, jellyfish, tube-dwelling anemones, and Hydra. Unlike jellyfish, sea anemones do not have a medusa stage in their life cycle.
Holothuria atra, commonly known as the black sea cucumber or lollyfish, is a species of marine invertebrate in the family Holothuriidae. It was placed in the subgenus Halodeima by Pearson in 1914, making its full scientific name Holothuria (Halodeima) atra. It is the type species of the subgenus.
Synaptidae is a family of sea cucumbers that have no tube feet, tentacle ampullae, retractor muscles, respiratory trees, or cuvierian tubules. They also lack radial canals of the water-vascular system, with only the circumoral ring present.
Synaptula lamperti is a species of sea cucumber in the family Synaptidae in the phylum Echinodermata, found on coral reefs in the Indo-Pacific region. The echinoderms are marine invertebrates and include the sea urchins, starfish and sea cucumbers. They are radially symmetric and have a water vascular system that operates by hydrostatic pressure, enabling them to move around by use of many suckers known as tube feet. Sea cucumbers are usually leathery, gherkin-shaped animals with a cluster of short tentacles at one end. They live on the sea bottom.
Holothuria thomasi, the tiger's tail, is a species of sea cucumber in the family Holothuriidae. Although it is the largest sea cucumber known in the western Atlantic Ocean, it is so well camouflaged that it was 1980 before it was first described. It is placed in the subgenus Thymiosycia making its full name Holothuria (Thymiosycia) thomasi.
Sclerodactyla briareus, commonly known as the hairy sea cucumber, is a species of marine invertebrate in the family Sclerodactylidae. It is found in shallow waters in the western Atlantic Ocean.
Holothuria edulis, commonly known as the edible sea cucumber or the pink and black sea cucumber, is a species of echinoderm in the family Holothuriidae. It was placed in the subgenus Halodeima by Pearson in 1914, making its full scientific name Holothuria (Halodeima) edulis. It is found in shallow water in the tropical Indo-Pacific Ocean.
Synapta maculata, the snake sea cucumber, is a species of sea cucumber in the family Synaptidae. It is found in shallow waters in the tropical Indo-Pacific Ocean. Sometimes growing as long as 3 m (10 ft), it is one of the longest sea cucumbers in the world.
Chiridotidae is a family of sea cucumbers found in the order Apodida. Within the family, there are 16 recognized genera all with different ranges of body types and functions. Sea cucumbers play a fundamental role in many marine ecosystems.
Euapta godeffroyi, the sticky snake sea cucumber, is a species of sea cucumber in the family Synaptidae. It is found on coral reefs in the tropical Indo-Pacific region.
Synaptula recta, sometimes known as the gut-like sea cucumber, is a species of sea cucumber in the family Synaptidae in the phylum Echinodermata. It occurs in shallow water in the tropical Indo-Pacific region.
Paraleptopentacta elongata is a species of sea cucumber in the family Cucumariidae. It is found in the northeastern Atlantic Ocean and parts of the Mediterranean Sea. It is an infaunal species, occupying a burrow in the seabed, from which its anterior and posterior ends project.
Holothuria (Cystipus) cubana is a species of sea cucumber in the family Holothuriidae. This species was first described by Ludwig in 1875.
Holothuria (Selenkothuria) glaberrima, also known as the brown rock sea cucumber, is a species of sea cucumber in the genus Holothuria, subgenus Selenkothuria. The cucumber is distributed in the Western Atlantic Ocean, the Caribbean Sea, and the Gulf of Mexico. The species is found at a depth of 0–42 meters.
Holothuria (Thymiosycia) impatiens, commonly known as the impatient sea cucumber or bottleneck sea cucumber, is a species of sea cucumber in the genus Holothuria, subgenus Thymiosycia.