| Dipolydora commensalis | |
|---|---|
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Annelida |
| Class: | Polychaeta |
| Order: | Spionida |
| Family: | Spionidae |
| Genus: | Dipolydora |
| Species: | D. commensalis |
| Binomial name | |
| Dipolydora commensalis (Andrews, 1891) [1] | |
| Synonyms | |
| |
Dipolydora commensalis is a species of polychaete worm in the family Spionidae. It has a commensal relationship with a hermit crab and occurs on the lower shore of coasts on the western side of the Atlantic Ocean.
Dipolydora commensalis is a burrowing worm that invariably bores into a gastropod mollusc shell that is being used by a hermit crab. The burrow usually starts at the columella at the side of the shell's aperture and a thin calcareous tube is secreted extending internally to the apex of the shell. The worm lives in this tube with its anterior end projecting. [2]
A pair of palps on the prostomium (first segment) catch food particles floating past. The worm uses both cilia and muscles to move the particles down a ciliary groove to its mouth. The worm is able to reject inedible material at the mouth and may be able to reject such material as it traverses the palps. [2]
The palps are able to regrow if they are damaged by movements of the hermit crab, and both the anterior and posterior parts of the worm are able to regenerate if it gets severed. In the laboratory, worms can live for four years, rather longer than most empty gastropod shells. [3]
This worm has been found to have a commensal relationship with nine different species of hermit crab. The worm is likely to gain advantage from the crab's mobility and the protection from predators that the crab's presence affords, as well as the avoidance of being overwhelmed by silt. Periodically a hermit crab will leave its shell in order to move into a larger one. During this period of vacancy, the worm is able to use nutrient granules stored in the wall of the gut. [4] There is usually competition among hermit crabs for vacant shells, so the empty shell is likely soon to be reoccupied. [5] It is likely that the hermit crab recognises the worm associated with it and does not attack it, but this aspect has not been studied in this species; however, in the case of some other commensal polychaete worms, such as Neanthes fucata , it has been demonstrated. [4]
The Sipuncula or Sipunculida is a class containing about 162 species of unsegmented marine annelid worms. The name Sipuncula is from the genus name Sipunculus, and comes from the Latin siphunculus meaning a "small tube".
Polychaeta is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes. Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are made of chitin. More than 10,000 species are described in this class. Common representatives include the lugworm and the sandworm or clam worm Alitta.
Hermit crabs are anomuran decapod crustaceans of the superfamily Paguroidea that have adapted to occupy empty scavenged mollusc shells to protect their fragile exoskeletons. There are over 800 species of hermit crab, most of which possess an asymmetric abdomen concealed by a snug-fitting shell. Hermit crabs' soft (non-calcified) abdominal exoskeleton means they must occupy shelter produced by other organisms or risk being defenseless.
Eunicidae is a family of marine polychaetes. The family comprises marine annelids distributed in diverse benthic habitats across Oceania, Europe, South America, North America, Asia and Africa. The Eunicid anatomy typically consists of a pair of appendages near the mouth (mandibles) and complex sets of muscular structures on the head (maxillae) in an eversible pharynx. One of the most conspicuous of the eunicids is the giant, dark-purple, iridescent "Bobbit worm", a bristle worm found at low tide under boulders on southern Australian shores. Its robust, muscular body can be as long as 2 m. Eunicidae jaws are known from as far back as Ordovician sediments. Cultural tradition surrounds Palola worm reproductive cycles in the South Pacific Islands. Eunicidae are economically valuable as bait in both recreational and commercial fishing. Commercial bait-farming of Eunicidae can have adverse ecological impacts. Bait-farming can deplete worm and associated fauna population numbers, damage local intertidal environments and introduce alien species to local aquatic ecosystems.
Spionidae is a family of marine worms within the Polychaeta. Spionids are selective deposit feeders that use their two grooved palps to locate prey. However, some spionids are capable of interface feeding, i.e. switching between deposit and suspension feeding.
Sabellastarte spectabilis is a species of benthic marine polychaete worm in the Sabellidae family. It is commonly known as the feather duster worm, feather duster or fan worm. It is native to tropical waters of the Indo-Pacific but has spread to other parts of the world. It is popular in aquariums because of its distinctive appearance and its ability to remove organic particles and improve water quality.
Chaetopterus variopedatus is a species of parchment worm, a marine polychaete in the family Chaetopteridae. It is found worldwide. However, recent discoveries from molecular phylogeny analysis show that Chaetopterus variopedatus sensu Hartman (1959) is not a single species.
Amphitrite ornata or ornate worm, is a species of marine polychaete worm in the family Terebellidae.
Palpata is a subclass of polychaete worm. Members of this subclass are mostly deposit feeders on marine detritus or filter feeders. Palpata has become superfluous with the elevation of Canalipalpata to subclass.
Pagurus prideaux is a species of hermit crab in the family Paguridae. It is found in shallow waters off the northwest coast of Europe and usually lives symbiotically with the sea anemone Adamsia palliata.
Scolelepis squamata is a species of polychaete worm in the family Spionidae. It occurs on the lower shore of coasts on either side of the Atlantic Ocean.
Polydora ciliata is a species of annelid worm in the family Spionidae, commonly known as a bristleworm. It is a burrowing worm and is found in the northeastern Atlantic Ocean and some other parts of the world.
Lepidonotus squamatus is a species of polychaete worm, commonly known as a "scale worm", in the family Polynoidae. This species occurs in both the Atlantic and the Pacific Oceans. It was first described by the Swedish naturalist Carl Linnaeus in 1758 as Aphrodita squamata but was later transferred to the genus Lepidonotus.
Neanthes fucata is a species of marine polychaete worm in the family Nereididae. It lives in association with a hermit crab such as Pagurus bernhardus. It occurs in the northeastern Atlantic Ocean, the North Sea and the Mediterranean Sea.
Polydora glycymerica is a species of annelid worm in the family Spionidae, native to the northwestern Pacific Ocean, where it lives commensally in association with a bivalve mollusc, usually Glycymeris yessoensis but occasionally with another species of clam. The worm intercepts food particles being drawn into the mollusc by its feeding current.
Glycymeris yessoensis is a species of bivalve mollusc in the family Glycymerididae. It can be found burrowing in soft sediment in shallow water in the Pacific Ocean around the coasts of China and Japan. It is often associated with a polychaete worm with which it forms a commensal relationship.
Eunoe bathydomus is a scale worm known from the north Atlantic Ocean at depths of 2000–3500 m.
Eunoe depressa is a scale worm known from off Alaska in the North Pacific and Arctic Oceans at depths of 35m or less.
Hartmania is a genus of marine polychaete worms belonging to the family Polynoidae, the scaleworms. Hartmania contains a single species, Hartmania moorei which is known from the north-west Atlantic Ocean off the coast of North America from shallow water to depths of about 80 m.
Uncopolynoe is a genus of marine polychaete worms belonging to the family Polynoidae, the scaleworms. Uncopolynoe contains a single species, Uncopolynoe corallicola which is known from the Red Sea at a depth of 1 m.