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.
Reef safe is a distinction used in the saltwater aquarium hobby to indicate that a fish or invertebrate is safe to add to a reef aquarium. There is no fish that is completely reef safe. Every fish that is commonly listed as reef safe are species that usually do not readily consume small fish or invertebrates. Fish listed as reef safe also do not bother fellow fish unless in some cases, for instance tangs, they do not get along with conspecifics and sometimes fish with similar color or body shape. Every fish has a personality, is different, and, in some cases, are opportunistic feeders. Tangs, which by most accounts are reef safe, may in adulthood eat some crustaceans shortly after they molt. Many larger predatory fish, for instance eels and pufferfish, will adapt very well to a reef tank and will be problem-free as long as they have sizable tank-mates and no crustaceans. Some aquarists have also had success in keeping smaller fish with predatory ones in reef tanks by adding the smaller fish at night, sometimes with newly rearranged rockwork.
A marine aquarium is an aquarium that keeps marine plants and animals in a contained environment. Marine aquaria are further subdivided by hobbyists into fish only (FO), fish only with live rock (FOWLR), and reef aquaria. Fish only tanks often showcase large or aggressive marine fish species and generally rely on mechanical and chemical filtration. FOWLR and reef tanks use live rock, a material composed of coral skeletons harboring beneficial nitrogen waste metabolizing bacteria, as a means of more natural biological filtration.
Zoanthids are an order of cnidarians commonly found in coral reefs, the deep sea and many other marine environments around the world. These animals come in a variety of different colonizing formations and in numerous different colors. They can be found as individual polyps, attached by a fleshy stolon or a mat that can be created from small pieces of sediment, sand and rock. The term "zoanthid" refers to all animals within this order Zoantharia, and should not be confused with "Zoanthus", which is one genus within Zoantharia.
Evisceration is a method of autotomy involving the ejection of internal organs used by animals as a defensive strategy. Sea cucumbers (Holothuroidea) eject parts of the gut in order to scare and defend against potential predators such as crabs and fish. The organs are regenerated in a few days by cells in the interior of the sea cucumber.
Thor amboinensis, commonly known as the squat anenome shrimp or sexy shrimp, is a species of shrimp found across the Indo-West Pacific and in parts of the Atlantic Ocean. It lives symbiotically on corals, sea anemones and other marine invertebrates in shallow reef communities.
An aquarium is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aquatic reptiles, such as turtles, and aquatic plants. The term aquarium, coined by English naturalist Philip Henry Gosse, combines the Latin root aqua, meaning 'water', with the suffix -arium, meaning 'a place for relating to'.
Cucumariidae is a family of sea cucumbers, marine animals with elongated bodies, leathery skins and tentacles that are found on the sea bed.
Holothuria scabra, or sandfish, is a species of sea cucumber in the family Holothuriidae. It was placed in the subgenus Metriatyla by Rowe in 1969 and is the type species of the subgenus. Sandfish are harvested and processed into "beche-de-mer" and eaten in China and other Pacific coastal communities.
Colochirus quadrangularis, commonly known as the thorny sea cucumber, is a species of sea cucumber in the family Cucumariidae. It is found in shallow seas in tropical parts of the Indo-Pacific region.
Colochirus robustus, commonly known as the robust sea cucumber or the yellow sea cucumber, is a species of sea cucumber in the family Cucumariidae. It is found in shallow seas in tropical parts of the central Indo-Pacific region. C. robustus belongs to the class Holothuroidea, a group of echinoderms called sea cucumbers and known for unusual behavior including evisceration, asexual reproduction, and regeneration. The robust sea cucumber has a soft body and lacks a spine, but it does have an endoskeleton consisting of microscopic spicules, or ossicles, made of calcium carbonate. C. robustus has a respiratory tree that allows it to extract oxygen for respiration, using the anus to pump water. The robust sea cucumber is an important dietary staple for many East and Southeast Asian populations, and has been used for medicinal purposes for hundreds of years. Recent research suggests that peptides from C. robustus enhance the activity of the immune system.
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.
Holothuria parvula, the golden sea cucumber, is a species of echinoderm in the class Holothuroidea. It was first described by Emil Selenka in 1867 and has since been placed in the subgenus Platyperona, making its full scientific name Holothuria (Platyperona) parvula. It is found in shallow areas of the Caribbean Sea and Gulf of Mexico and is unusual among sea cucumbers in that it can reproduce by breaking in half.
Holothuria leucospilota, commonly known as the black sea cucumber or black tarzan, is a species of marine invertebrate in the family Holothuriidae. It is placed in the subgenus Mertensiothuria making its full scientific name Holothuria (Mertensiothuria) leucospilota. It is the type species of the subgenus and is found on the seabed in shallow water in the Indo-Pacific.
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.
Eupentacta quinquesemita is a species of sea cucumber, a marine invertebrate with an elongated body, a leathery skin and tentacles surrounding the mouth. It is commonly known as the stiff-footed sea cucumber or white sea cucumber, and occurs on rocky coasts in the northeastern Pacific Ocean.
Actinopyga varians, the Pacific white-spotted sea cucumber or Hawaiian sea cucumber, is a species of sea cucumber in the family Holothuriidae. It is found in the Pacific Ocean near Hawaii and also in the Indo-Pacific Ocean.
Holothuria (Platyperona) difficilis is a species of sea cucumber in the family Holothuriidae. Holothuria comes from Latin but is originally taken from Greek. Its meaning is a plantlike animal whose origin is uncertain.
Holothuria pervicax is a species of sea cucumber in the genus Holothuria. It is commonly called the stubborn sea cucumber due to its inability to be kept alive in captivity. It is commonly found buried beneath rocks on reefs in warm waters.
Pseudocolochirus axiologus, the Australian sea apple, is a species of sea apple within the family Cucumariidae. The species is found distributed in marine waters north of Australia, occurring near and in areas such as the Coral Sea, Northern Territory, Queensland, and Western Australia. Habitats include waters 19 to 200 meters below sea level in neritic zones. Individuals reach lengths of 22 to 26 centimeters, with body colorations of light to dark blue with red feet and tentacles colored violet, blue, and red with white tips. The species feeds through filter feeding, catching organic matter such as algae, phytoplankton, and detritus with its tentacles. It is occasionally kept in saltwater tanks in the aquarium hobby, however is recommended to only be cared by those with expertise in the hobby due to a risk of it secreting toxins if stressed, such as with some fish species that are prone to pick at the tentacles of sea cucumbers.
