Nephasoma minutum | |
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Scientific classification | |
Kingdom: | Animalia |
Phylum: | Sipuncula |
Class: | Sipunculidea |
Order: | Golfingiida |
Family: | Golfingiidae |
Genus: | Nephasoma |
Species: | N. minutum |
Binomial name | |
Nephasoma minutum (Keferstein, 1862) [1] | |
Synonyms | |
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Nephasoma minutum is a marine invertebrate of the phylum Sipuncula, commonly known as peanut worms because of their shape when contracted. [2] It is a cylindrical, unsegmented worm with a crown of tentacles around the mouth. These worms live in crevices in the rocks or in burrows in shallow water in Western Europe, [3] and the eastern United States. [1]
Reaching a maximum length of about 1.5 cm (0.6 in), Nephasoma minutum, like all peanut worms, has a cylindrical trunk and a narrower, retractable anterior section known as the introvert. The mouth is at the end of the introvert which can be extended to feed or retracted into the body at other times. In this species the trunk is in excess of three times as long as its width and the introvert is a similar length to the trunk, which is cylindrical and smooth. There are two tentacles and up to six irregular lobular projections near the mouth and there are a few irregularly-arranged, spine-like hooks near the tip of the introvert, but these may be absent in adults. This peanut worm varies in colour, and may be white, yellowish-grey or orange. [3] [4] This description applies to populations in the northeastern Atlantic that are hermaphrodites; other populations with slightly differing characteristics, and some which are gonochoristic (having separate sexes), are often additionally referred to as Nephasoma minutum, which is likely to be a "taxonomic wastebasket". [3]
The range of N. minutum in the northeastern Atlantic Ocean extends from Sweden to the British Isles and the coast of France. It is also reported from the eastern [1] and western coasts of the United States. [5] Present from the lower intertidal zone down to about 50 m (160 ft), it burrows into sand, gravel and mud or hides in crevices in the rock. [3]
A detritivore, N. minutum unselectively collects organic particles with its tentacles and ingests them when the introvert is drawn in. [6] It is a hermaphrodite; most eggs laid by this class are spherical, but N. minutum produces large, elongate eggs with yolks on which the larvae can feed for two months during their direct development. [5]
The Sipuncula or Sipunculida is a group containing about 162 species of bilaterally symmetrical, unsegmented marine worms. The name Sipuncula is from the genus name Sipunculus, and comes from the Latin siphunculus meaning a "small tube". Sipuncula seems to be closely related to Myzostomida, and Annelida.
The Echiura, or spoon worms, are a small group of marine animals. Once treated as a separate phylum, they are now considered to belong to Annelida. Annelids typically have their bodies divided into segments, but echiurans have secondarily lost their segmentation. The majority of echiurans live in burrows in soft sediment in shallow water, but some live in rock crevices or under boulders, and there are also deep sea forms. More than 230 species have been described. Spoon worms are cylindrical, soft-bodied animals usually possessing a non-retractable proboscis which can be rolled into a scoop-shape to feed. In some species the proboscis is ribbon-like, longer than the trunk and may have a forked tip. Spoon worms vary in size from less than a centimetre in length to more than a metre.
Bispira brunnea, the social feather duster or cluster duster, is a species of marine bristleworm. They tend to live in groups of individuals, and are common off the Caribbean islands in southeast North America. The feather duster has one crown of various colors, however, the color of the crown seems to be consistent within individual colonies.
Golfingia vulgaris is a marine invertebrate belonging to the phylum Sipuncula, the peanut worms. It is a cylindrical, unsegmented worm with a crown of tentacles around the mouth. It lives in burrows in shallow seas in various parts of the world.
Sipunculus nudus is a cosmopolitan species of unsegmented marine worm of the phylum Sipuncula, also known as peanut worms.
Aspidosiphonidae is a family of peanut worms. It is the only family in the monotypic order Aspidosiphonida, which is in the class Phascolosomatidea.
Phascolosomatidea is a class of peanut worms containing two orders:-
Themiste is a genus of peanut worms. It is the only genus in the family Themistidae.
Golfingiida is an order of peanut worms. The tentacles form a circle around the mouth whereas those of the sister taxon, Phascolosomatidea, are only found above the mouth. Most species burrow in the substrate but some live in the empty shells of gastropods. It is the only order in the monotypic class Sipunculidea and contains the following families:
Phascolopsis gouldii is a species of unsegmented benthic marine worm, also known as a peanut worm or star worm. It lives in burrows in muddy sand in shallow waters off North America.
Onchnesoma is one of the two genera that constitute the family Phascolionidae of Phylum Sipuncula, described by Koren and Danielssen established in 1873 as the type species to Onchnesoma steenstrupii.
Nephasoma rimicola is a marine invertebrate belonging to the phylum Sipuncula, the peanut worms. This worm occurs in the northeastern Atlantic Ocean.
Priapulus caudatus is a marine invertebrate belonging to the phylum Priapulida, the penis worms. It is a cylindrical, unsegmented worm which burrows in soft sediment on the seabed. It has a circumpolar distribution.
Phascolosoma granulatum is a species of peanut worm in the family Phascolosomatidae. It is found in shallow water in the northeastern Atlantic Ocean and the Mediterranean Sea.
Aspidosiphon elegans is a species of unsegmented benthic marine worm in the phylum Sipuncula, the peanut worms. It is a bioeroding species and burrows into limestone rocks, stones and corals. It occurs in the western Indo-Pacific region, the Red Sea, and the tropical western Atlantic Ocean, and is invasive in the eastern Mediterranean Sea.
Aspidosiphon muelleri is a species of unsegmented benthic marine worm in the phylum Sipuncula, the peanut worms. This worm is found in the eastern Atlantic Ocean, the Mediterranean Sea and in various locations in the Indo-Pacific region at depths down to about 1,000 m (3,300 ft).
Themiste cymodoceae is a species of unsegmented benthic marine worm in the phylum Sipuncula, the peanut worms. It is native to shallow waters around Australia and in the South China Sea where it lives in a cavity it creates among seagrass roots and in empty oyster shells.
Themiste hennahi is a species of unsegmented benthic marine worm in the phylum Sipuncula, the peanut worms. It is native to shallow waters on the Pacific coast of North and South America. This worm was first described in 1828 by the British zoologist John Edward Gray as Themiste hennahi, the type specimen having been collected by the Rev. W. Hennah, with the type locality being Peru.
Themiste pyroides is a species of unsegmented benthic marine worm in the phylum Sipuncula, the peanut worms. It occurs in the intertidal zone and shallow water in the western Atlantic Ocean and the northeastern Pacific Ocean. It lives in crevices and under rocks, extending its "crown" of branching tentacles into the surrounding water to feed.
Thysanocardia procera is a marine invertebrate belonging to the phylum Sipuncula, the peanut worms. It is a cylindrical, unsegmented worm with a crown of tentacles around the mouth. It is native to shallow seas in the northeastern Atlantic Ocean.