| Syllis ramosa | |
|---|---|
 | |
| Syllis ramosa (on right) | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Annelida |
| Class: | Polychaeta |
| Order: | Phyllodocida |
| Family: | Syllidae |
| Genus: | Syllis |
| Species: | S. ramosa |
| Binomial name | |
| Syllis ramosa | |
Syllis ramosa is a species of polychaete worm in the family Syllidae. [2] It is found in the deep sea where it lives within the tissues of a sponge. It was the first branching polychaete worm to be discovered, with each worm having a single head and multiple anuses.
During the period 1872 to 1876, the Royal Navy's HMS Challenger was used in the Challenger expedition to survey and explore the world's oceans. One of the unknown animals dredged from the ocean depths near the Philippines was a species of sponge which was found to contain numerous branching worms inside its cavities. In 1879, one of these worms was formally described by the Scottish marine biologist William Carmichael McIntosh, who named it Syllis ramosa. [1] Branching polychaete worms were previously unknown. [3]
This bristle worm was first discovered living commensally with a sponge at a depth of about 250 m (820 ft) near the Philippines and at a depth of 170 m (560 ft) in the Arafura Sea. [4] Further branching worms have occasionally been found in different locations and have been ascribed to S. ramosa despite subtle differences in morphology; they are hard to examine because of the difficulty of extracting them from the sponge tissue. However a new species of branching worm ( Ramisyllis multicaudata ) was described in 2012. [3]
The heads of the two individual S. ramosa brought to the surface by the Challenger were located in the bases of glass sponges of the class Hexactinellida. The rest of the worms' bodies were in the passages of the sponges. The bodies branched repeatedly so that each worm had a single head and many anuses. [4]
S. ramosa is a "stolonate" worm and has a bizarre life cycle. The terminal portion of a branch is known as a "stolon", and develops an extra head with large eyes and no mouth. The gut in this part of the animal is absorbed, the muscles are rearranged to facilitate swimming and the stolon becomes a storage receptacle for the eggs or sperm. When the breeding period arrives, the stolon becomes detached and swims to the surface of the sea, in a process termed "epitoky". Here the gametes are released and the stolon dies. Meanwhile, the parent worm remains safely in its sponge home and produces more stolons. [5] [6]
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 Polychaeta, also known as the bristle worms or polychaetes, are a paraphyletic class of annelid worms, generally marine. 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.
Entoprocta, whose name means "anus inside", or Kamptozoa, is a phylum of mostly sessile aquatic animals, ranging from 0.1 to 7 millimetres long. Mature individuals are goblet-shaped, on relatively long stalks. They have a "crown" of solid tentacles whose cilia generate water currents that draw food particles towards the mouth, and both the mouth and anus lie inside the "crown". The superficially similar Bryozoa (Ectoprocta) have the anus outside a "crown" of hollow tentacles. Most families of entoprocts are colonial, and all but 2 of the 150 species are marine. A few solitary species can move slowly.
The Clitellata are a class of annelid worms, characterized by having a clitellum - the 'collar' that forms a reproductive cocoon during part of their life cycles. The clitellates comprise around 8,000 species. Unlike the class of Polychaeta, they do not have parapodia and their heads are less developed.
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.
Marine invertebrates are the invertebrates that live in marine habitats. Invertebrate is a blanket term that includes all animals apart from the vertebrate members of the chordate phylum. Invertebrates lack a vertebral column, and some have evolved a shell or a hard exoskeleton. As on land and in the air, marine invertebrates have a large variety of body plans, and have been categorised into over 30 phyla. They make up most of the macroscopic life in the oceans.
Serpula is a genus of sessile, marine annelid tube worms that belongs to the family Serpulidae. Serpulid worms are very similar to tube worms of the closely related sabellid family, except that the former possess a cartilaginous operculum that occludes the entrance to their protective tube after the animal has withdrawn into it. The most distinctive feature of worms of the genus Serpula is their colorful fan-shaped "crown". The crown, used by these animals for respiration and alimentation, is the structure that is most commonly seen by scuba divers and other casual observers.
Eudistylia is a genus of marine polychaete worms. The type species is Eudistylia gigantea, now accepted as Eudistylia vancouveri. This worm lives in a parchment-like tube with a single opening from which a crown of tentacles projects when the worm is submerged. It is a sessile filter feeder.
Serpula vermicularis, known by common names including the calcareous tubeworm, fan worm, plume worm or red tube worm, is a species of segmented marine polychaete worm in the family Serpulidae. It is the type species of the genus Serpula and was first described by Carl Linnaeus in his 1767 12th edition of Systema Naturae. It lives in a tube into which it can retract.
Neofibularia nolitangere, commonly known as the touch-me-not sponge, is a species of sea sponge in the family Biemnidae. It is found in shallow waters in the Western Atlantic Ocean and the Caribbean Sea.
Haplosyllis spongicola, the sponge worm, is a species of polychaete worm in the family Syllidae. It was previously classified as Syllis spongicola and is part of a species complex of closely related species that are difficult to distinguish morphologically and where the demarcation between them is unclear. It is found in shallow temperate, subtropical and tropical seas worldwide, wherever its host sponges are found.
Amathia vidovici is a species of colonial bryozoans with a tree-like structure. It is found in shallow waters over a wide geographical range, being found in both the Atlantic and Pacific Oceans and adjoining seas.
The annelids, also known as the ringed worms or segmented worms, are a large phylum, with over 22,000 extant species including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecologies – some in marine environments as distinct as tidal zones and hydrothermal vents, others in fresh water, and yet others in moist terrestrial environments.
Cyril Crossland was an English zoologist.
Eunice norvegica is an aquatic polychaete worm found in deep water on the seabed of the northern Atlantic Ocean as well as in the Pacific and Indian Oceans. It is a tubeworm and is often associated with deep water corals.
Phyllodoce mucosa is a species of polychaete worm in the family Phyllodocidae. It is found intertidally in both the Pacific and Atlantic Oceans, typically on sandy or muddy seabeds.
Ramisyllis multicaudata is a species of polychaete worm in the family Syllidae. It was found in Darwin Harbour, Australia, where it was living within the tissues of a sponge of the genus Petrosia. It was the second branching species of polychaete worm to have been discovered, the first having been Syllis ramosa, a deep water species, more than a century earlier.
Syllidae is a family of small to medium-sized polychaete worms. Syllids are distinguished from other polychaetes by the presence of a muscular region of the anterior digestive tract known as the proventricle.
Syllis prolifera is a species of polychaete worm in the family Syllidae. It has a cosmopolitan distribution. It was first described in 1852 by the Russian/German zoologist August David Krohn who gave it the name Syllis prolifera.
Eunice aphroditois is a benthic bristle worm of warm marine waters. It lives mainly in the Atlantic Ocean, but can also be found in the Indo-Pacific. It ranges in length from less than 10 cm (4 in) to 3 m (10 ft). Its exoskeleton displays a wide range of colors, from black to purple to metallic. This species is an ambush predator; it hunts by burrowing its whole body in soft sediment on the ocean floor and waiting until its antennae detect prey. It then strikes with its sharp mouthparts. It may also be found among coral reefs.