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.
Coralline algae are red algae in the order Corallinales. They are characterized by a thallus that is hard because of calcareous deposits contained within the cell walls. The colors of these algae are most typically pink, or some other shade of red, but some species can be purple, yellow, blue, white, or gray-green. Coralline algae play an important role in the ecology of coral reefs. Sea urchins, parrot fish, and limpets and chitons feed on coralline algae. In the temperate Mediterranean Sea, coralline algae are the main builders of a typical algal reef, the Coralligène ("coralligenous"). Many are typically encrusting and rock-like, found in marine waters all over the world. Only one species lives in freshwater. Unattached specimens may form relatively smooth compact balls to warty or fruticose thalli.
Rhodoliths are colorful, unattached calcareous nodules, composed of crustose, benthic marine red algae that resemble coral. Rhodolith beds create biogenic habitat for diverse benthic communities. The rhodolithic growth habit has been attained by a number of unrelated coralline red algae, organisms that deposit calcium carbonate within their cell walls to form hard structures or nodules that resemble beds of coral.
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.
Aspidosiphonidae is a family of peanut worms. It is the only family in the monotypic order Aspidosiphonida, which is in the class Phascolosomatidea.
Alcyonium acaule or Mediterranean sea-finger is a species of soft coral in the family Alcyoniidae. It is found at moderate depths on shaded rocks in the Mediterranean Sea and adjoining parts of the Atlantic Ocean.
Brachidontes pharaonis is a species of mussel from the family Mytilidae. It is native to the Indian Ocean and the Red Sea, and has colonised the Mediterranean Sea where it is regarded as an invasive species.
Apogonichthyoides pharaonis, the Pharaoh cardinalfish, is a species of cardinalfish from the family Apogonidae which is found the western Indian Ocean and Red Sea. It is one of a group of species which have colonised the eastern Mediterranean Sea from the Red Sea via the Suez Canal, a process known as Lessepsian migration.
Nephasoma minutum is a marine invertebrate of the phylum Sipuncula, commonly known as peanut worms because of their shape when contracted. 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, and the eastern United States.
Nephasoma rimicola is a marine invertebrate belonging to the phylum Sipuncula, the peanut worms. This worm occurs in the northeastern Atlantic Ocean.
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 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).
Sipunculus robustus is a species of unsegmented benthic marine worm in the phylum Sipuncula, the peanut worms.
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.
Acanthochitona crinita is a species of marine chiton in the family Acanthochitonidae. It is found on rocky coasts in the northeastern Atlantic Ocean, the North Sea and the Mediterranean Sea.
