| Cerebratulus lacteus | |
|---|---|
 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Nemertea |
| Class: | Anopla |
| Order: | Heteronemertea |
| Family: | Lineidae |
| Genus: | Cerebratulus |
| Species: | C. lacteus |
| Binomial name | |
| Cerebratulus lacteus (Leidy, 1851) [1] | |
| Synonyms [1] | |
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Cerebratulus lacteus, the milky nemertean or milky ribbon worm, is a proboscis worm in the family Lineidae. This ribbon worm has a wide geographical range on both sides of the northern Atlantic Ocean. [1]
Cerebratulus lacteus grows to a length of about 120 cm (4 ft) and a width of 22 mm (0.9 in). [1] The head is rounded and flattened, with a pair of cerebral organs and cephalic grooves, but no eyes. The head is not readily distinguishable from the body, which is flattened and gradually tapers towards the tail, where there is a slender caudal cirrus. This worm is usually milky-white in colour but may be pink. [2]
Cerebratulus lacteus burrows in muddy sediments into which it can burrow rapidly. It is a voracious predator and has been observed attacking bivalve molluscs and crustaceans. [3] The proboscis is everted (turned inside out) and the lower half of the Atlantic jackknife clam (Ensis directus) is enveloped. In an effort to escape, the clam works its way out of the sediment and may then be at risk of predation by birds. Soft clams, such as Mya arenaria are also attacked. In this case, the ribbonworm inserts the tip of its proboscis through the siphon and consumes the soft tissues. [4] It is not clear whether the ribbonworm preys on hard clams, but a high abundance of this worm at one location near Prince Edward Island was thought to be responsible for the high mortality among newly transplanted hard clams. [4]
As is the case with other nemertean worms, the sexes are separate in this species and fertilisation is external. Reproduction can also occur by fragmentation, as this worm readily breaks into pieces which can grow into new organisms. [1]
Cerebratulus lacteus produces several homologous polypeptide cytotoxins that are active in breaking down the membranes of human red blood cells, as well as several neurotoxins. These substances are being researched. [5]
Clams have been identified as a useful subject for aquaculture in Canada. Because Cerebratulus lacteus is a threat to such activities, research is ongoing into the ribbonworm and what governs its patchy distribution, with a view to being able to better control it. [6]
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.
Nemertea is a phylum of animals also known as ribbon worms or proboscis worms, consisting of 1300 known species. Most ribbon worms are very slim, usually only a few millimeters wide, although a few have relatively short but wide bodies. Many have patterns of yellow, orange, red and green coloration. The foregut, stomach and intestine run a little below the midline of the body, the anus is at the tip of the tail, and the mouth is under the front. A little above the gut is the rhynchocoel, a cavity which mostly runs above the midline and ends a little short of the rear of the body. All species have a proboscis which lies in the rhynchocoel when inactive but everts to emerge just above the mouth to capture the animal's prey with venom. A highly extensible muscle in the back of the rhynchocoel pulls the proboscis in when an attack ends. A few species with stubby bodies filter feed and have suckers at the front and back ends, with which they attach to a host.
The bootlace worm is a species of ribbon worm and one of the longest known animals, with specimens up to 55 m (180 ft) long being reported, although this has not been confirmed. Its mucus is highly toxic.
The Atlantic jackknife clam, Ensis leei, also known as the bamboo clam, American jackknife clam or razor clam, is a large edible marine bivalve mollusc found on the North American Atlantic coast, from Canada to South Carolina. The species has also been introduced to Europe. The name "razor clam" is also used to refer to different species such as the Pacific razor clam or Razor shell.
Enopla is one of the classes of the worm phylum Nemertea, characterized by the presence of a peculiar armature of spines or plates in the proboscis.
Parborlasia corrugatus is a proboscis worm in the family Cerebratulidae. This species of proboscis or ribbon worm can grow to 2 metres in length, and lives in marine environments down to 3,590 metres (11,780 ft). This scavenger and predator is widely distributed in cold southern oceans.
Spatangus purpureus, commonly known as the purple heart urchin, is a species of sea urchin in the family Spatangidae. It is found in the eastern Atlantic Ocean and the Mediterranean Sea, where it lives immersed in the sediment.
Solecurtus strigilatus, also known as the rosy razor clam, is a species of saltwater clam, a marine bivalve mollusc in the family Solecurtidae. This mollusc is a suspension feeder and can burrow with great rapidity to escape predators. It is an unusual bivalve in that its shell valves are too small to contain all the soft tissue, and the animal is unable to retreat into its shell.
Saccoglossus bromophenolosus is a species of acorn worm occurring in the northwestern Atlantic Ocean and the northeastern Pacific Ocean. It grows to a length of about 20 cm (8 in) and lives in a burrow in soft sediment in the intertidal and subtidal zones. The scientific name refers to 2,4-dibromophenol, a secondary metabolite present in this worm.
Tubulanus polymorphus is a species of ribbon worm in the phylum Nemertea. It is found in the northern Atlantic Ocean and the northern Pacific Ocean. It occurs on the lower shore down to about 50 m (160 ft), on sand or gravel, under stones and among seaweed.
Tubulanus superbus, commonly known as the football jersey worm, is a species of ribbon worm in the phylum Nemertea. Found in the northern Atlantic Ocean, the North Sea and the Mediterranean Sea, it occurs from the lower shore down to about 80 m (260 ft), on sand or gravel.
Tubulanus annulatus, commonly known as the football jersey worm, is a species of ribbon worm in the phylum Nemertea. It ranges across the northern Atlantic Ocean, the North Sea and the Mediterranean Sea, being present from the lower shore down to about 40 m (130 ft), on sand, gravel and other habitats.
Lineus sanguineus, the banded nemertean or social lineus, is a species of nemertean ribbon worm in the family Lineidae. It occurs in the northeastern Atlantic Ocean as well as on both coasts of North America. It burrows in muddy sand from the mid-tidal zone downwards and conceals itself in crevices and under stones.
Cerebratulus marginatus is a proboscis worm in the family Lineidae. This ribbon worm has an Arctic distribution, and in the North Atlantic Ocean ranges as far south as Cape Cod and the Mediterranean Sea while in the Pacific Ocean it extends southwards to California.
Urechis caupo is a species of spoon worm in the family Urechidae, commonly known as the innkeeper echiuran, the fat innkeeper worm, the innkeeper worm, or the penis fish. It is found in shallow water on the west coast of North America, between southern Oregon and Baja California, where it forms a U-shaped burrow in the sediment and feeds on plankton using a mucus net.
Ochetostoma erythrogrammon is a species of spoon worm in the family Thalassematidae. It is found in shallow water in the Atlantic Ocean, the Mediterranean Sea, and the Indian and Pacific Oceans, burrowing in soft sediment.
Echiurus echiurus is a species of spoon worm in the family Echiuridae. It is found in the North Atlantic Ocean and a subspecies is found in Alaska. It burrows into soft sediment and under boulders and stones in muddy places.
Ikeda taenioides is a species of spoon worm in the family Ikedidae. It is native to the northern Pacific Ocean where it is found in the subtidal waters around Japan.
Maxmuelleria lankesteri is a species of spoon worm in the family Bonelliidae. It is found in the North Atlantic Ocean. It burrows into soft sediment on the seabed, mostly in deep water.
Neurotoxin B-IV is a venom peptide secreted by a large marine worm called Cerebratulus lacteus that inhabits the northeastern coast of North America. This neurotoxin belongs to a major type of B polypeptide neurotoxins, which appear to be selectively toxic for crustaceans. The mode of action for neurotoxin B-IV has not been clearly established. However, it is likely that B neurotoxins prolong the repolarization phase of action potentials by interacting with voltage-gated sodium channels.