Holothuria parvula
A golden sea cucumber that reproduces by splitting in half.
Holothuria parvula, commonly known as the golden sea cucumber, belongs to the echinoderm class Holothuroidea. Its full scientific name is Holothuria (Platyperona) parvula, as it was first described by Emil Selenka in 1867 and later placed in the subgenus Platyperona. This species inhabits shallow waters of the Caribbean Sea and the Gulf of Mexico, and it stands out among sea cucumbers for its ability to reproduce by splitting in two.
This sea cucumber has a roughly cylindrical body, with tube feet on its underside and conical, wart-like bumps on its upper surface. Its coloration is golden.
Its range includes the tropical western Atlantic, the Caribbean Sea, and the Gulf of Mexico, specifically Bermuda, the West Indies, the Bahamas, the Lesser Antilles, Colombia, and Venezuela. It lives on sandy seabeds in shallow water.
Holothuria parvula feeds on detritus, algae, and plankton, moving across the seabed or over rocks using its tube feet. When threatened or stressed, it can expel sticky threads called cuvierian tubules from its anus. These threads contain a toxin known as holothurin, which entangles small fish or crabs, preventing their escape and leading to their death. The sea cucumber then moves away and eventually regenerates the tubules.
Asexual reproduction occurs through transverse fission. In Bermuda, this happens during summer when water temperatures reach at least 25 °C (77 °F). A split forms in the body wall, deepens, and extends across the body until it breaks apart. The two resulting pieces are roughly equal in size, and each can regenerate missing organs. The gut is crucial for survival; both front and rear sections can resume feeding within two months, while the gonads take longer to regenerate. In a study of the Bermudan population, no juvenile specimens were found, leading researchers to believe that little or no recruitment from planktonic larvae occurs. Instead, fission appears to be an annual event and the primary means of reproduction.
Quick Facts
- Taxon
- Holothuria parvula
Facts from the source article.
Lore & Background
Holothuria parvula is a roughly cylindrical sea cucumber with tube feet on the underside and conical warty protuberances on the upper surface. It is a golden colour. It is found on the seabed in shallow water in the tropical western part of the Atlantic, the Caribbean Sea and Gulf of Mexico. Its range includes Bermuda, the West Indies, the Bahamas, the Lesser Antilles, Colombia and Venezuela.
Holothuria parvula lives on a sandy seabed and feeds on detritus, algae and plankton. It crawls across the surface or manoeuvres across rocks with its tube feet. If attacked or stressed, this sea cucumber may eject a mass of sticky threads called cuvierian tubules from its anus. These contain a toxin called holothurin and entangle small fish or crabs which are unable to free themselves and eventually die. Meanwhile, the sea cucumber continues on its way and regenerates the tubules in the course of time.
Holothuria parvula is able to reproduce asexually by transverse fission. In Bermuda, it does this during the summer when the water temperature rises to at least 25 °C (77 °F). A split occurs in the body wall that gradually deepens and extends across the body which eventually breaks apart. The two parts so formed are about equal in size and each can regenerate the lost organs. The gut is the most important organ for survival and both front and rear portions are able to feed again within two months. The gonads take longer to regenerate. In the Bermudan population studied, no juvenile specimens of Holothuria parvula were found during the course of the study, and the researchers thought it likely that little or no recruitment involving planktonic larvae takes place and that fission is an annual event and the main means of reproduction.
Reader's Guide
Holothuria parvula is notable primarily for its unusual reproductive strategy among sea cucumbers: asexual reproduction by transverse fission. In the Bermudan population studied, this fission occurs annually during summer when water temperature reaches at least 25 °C, and researchers found no juvenile specimens, suggesting that little or no recruitment via planktonic larvae occurs, making fission the main means of reproduction. This challenges typical echinoderm life cycles that rely on larval dispersal. Additionally, the species employs a chemical defense mechanism: when attacked or stressed, it ejects sticky cuvierian tubules containing the toxin holothurin, which entangle and kill small fish or crabs. The sea cucumber then regenerates the tubules over time. Its golden coloration and cylindrical body with tube feet and conical warty protuberances distinguish it visually. First described by Emil Selenka in 1867 and placed in the subgenus Platyperona, it inhabits shallow sandy seabeds across the Caribbean Sea, Gulf of Mexico, and adjacent regions including Bermuda, the West Indies, the Bahamas, the Lesser Antilles, Colombia, and Venezuela. Its diet consists of detritus, algae, and plankton, and it moves using tube feet. The species' reliance on fission for reproduction and its ability to regenerate both body parts and defensive tubules highlight its ecological adaptability in shallow tropical waters.
Did You Know?
- Holothuria parvula can reproduce by breaking in half, a process called transverse fission.
- Both front and rear halves from fission can regenerate lost organs and feed again within two months.
Frequently Asked Questions
What is Holothuria parvula?
It's the golden sea cucumber, an echinoderm in the class Holothuroidea that Emil Selenka first described in 1867. Fans often call it by its common name because of its striking golden coloration.
What does Holothuria parvula look like?
It has a roughly cylindrical body with a golden hue, tube feet running along its underside, and conical wart-like bumps dotting its upper surface. The overall shape is compact and rounded rather than elongated.
Where does Holothuria parvula live?
You'll find it in shallow sandy seabeds across the Caribbean Sea and the Gulf of Mexico. It stays in relatively warm, near-shore waters rather than deep ocean trenches.
How does Holothuria parvula reproduce?
It can split its own body in two, a form of asexual fission that sets it apart from many other sea cucumbers. This means a single individual can produce two separate offspring without a mate.
What is the full scientific name and subgenus of Holothuria parvula?
Its complete binomial is Holothuria (Platyperona) parvula, placing it in the subgenus Platyperona within the genus Holothuria. The parenthetical subgenus was added after Selenka's original 1867 description to reflect later taxonomic revisions.
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