#nemerteans

[dougdimmadodo]

Common Atlantic Ribbon Worm (Tubulanus polymorphus)

Family: Tubulanus Family (Tubulanidae)

IUCN Conservation Status: Unassessed

Like other ribbon worms, this brightly coloured marine worm has a relatively long but extremely thin unsegmented body, and is an active predator; after locating prey using a set of chemical-sensing pits on its head it extends a sticky, flexible, tube-like appendage known as a proboscis (although unlike the proboscises of some insects this structure is separate from their digestive system) from just above it mouth, ensnaring prey and injecting it with paralysing venom. After prey (mainly smaller marine invertebrates, especially other worms) has been subdued the proboscis either passes it into a simple mouth or, if its too large to be swallowed whole, secretes fluids that break food down externally to accommodate for the worm's lack of an ability to chew.

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Image Source: Here

[z0rrp]

Haha worm

@theratcloset to yo liek mi artvorck

Zerzebzbeb piramide pipipi zerb zeerzeer

[sbnkalny]

Microchaetus rappi,[2] and 58 metres (190 ft) for the african Giant earthworm, Microchaetus rappi,[2] and 58 metres (190 ft) for the Marine nemertean worm (bootlace worm), Lineus longissimus.[3] various types of power and beauty frazzle your heart like a kettle chip, we love there pizza.

[wormmongering]

Would it be weird if I asked for people to send me worm pics?

[mbari-blog]

Ribbon worm with the smooth moves 💃🏻⁠

Nemerteans are neither worms nor fish, although they look a bit like both. They are unique enough to belong in their own phylum. Most nemerteans burrow in sediments or between crevices in rocks, shells, and other seafloor habitats, but some, like this one, live in the open ocean, never touching the seafloor. Nemerteans range in length from a few millimeters to 30 meters stretched (nearly 100 feet) in length (most species commonly measure about 20 centimeters, just about eight inches, or less).⁠ ⁠ This ribbon worm (Phallonemertes sp.) was observed at 1,630 meters (5,348 feet).

[tt-squid]

nemertean propoganda (Parborlasia corrugatus) (theyre so cool)

Taxonomy Tournament: Spiralia

Lingulida. Brachiopods of this order have a long shell and a fleshy stalk with which it burrows into sand/mud. Includes Lingula, the oldest animal genus with species still alive today

Nemertea. This phylum, known as the ribbon worms, is made up of mostly carnivorous worms with a proboscis

[crevicedwelling]

some invasive worms I found in Florida!

first is a Caenoplana sp., a flatworm now found across the tropics but which is likely native to Australia (or nearby). they feed on arthropods, including isopods.

next is Bipalium vagum, the Wandering Hammerhead Flatworm. its specific name alludes to the fact that it too has spread itself throughout the tropics. its close relatives in the US are also probably native to East Asia, but while those eat only earthworms, B. vagum feeds on only snails. Bipalium are known to produce tetrodotoxin, a nasty poison responsible for the toxicity of fugu pufferfish.

third is an Anisorhynchodemus sp., and its original distribution is also unknown. the genus it’s placed in is essentially a wastebasket—all the rhynchodemine flatworms that can’t be connected with an older, outdated classification method get lumped there. these guys are predators of arthropods, and also love sucking isopods out of their shells. when seized, they cleave their own rears off; the biggest one I have failed to autotomize its tail completely and now has two tails (not pictured).

despite a similar appearance, the last isn’t a flatworm, but an entire different phylum of animals! the nemertean (ribbon worm) Geonemertes pelaensis is just one of 13 species of nemertean that live on land with the remaining 1,300 living in saltwater. and, you guessed it, it’s native to *somewhere in the Indopacific* and is now found all over the tropics because of humans transporting it accidentally with soil. it is a predator of small arthropods, including spiders and isopods, which it captures with a sticky, venomous projectile proboscis. good video of that on its Wikipedia page.

so yeah that’s my worms. hope you like the worms

[todaysbug]

December 12th, 2023

Sea Mouse (Aphrodita aculeata)

Distribution: Found in marine habitats of the northern hemisphere; the North Atlantic, North Sea, Baltic Sea and the Mediterranean Sea.

Habitat: Benthic; lives from the sublittoral zone down to a maximum of 1000 metres.

Diet: Carnivorous; feeds mainly on other invertebrates such as small crabs, hermit crabs, mollusks, nemerteans and other polychaete worms.

Description: Despite its caterpillar-like appearance, the sea mouse is actually a polychaete worm! Its most obvious feature is the dense mat of hairs, or setae, that cover its body. While most are a brownish-red colour, these are intermingled with glassy hairs (especially on either side of its body), which have an iridescent quality. These hairs are usually reddish in colour, but become a bright bluish-green when the light hits them a certain way. This acts as a defence mechanism to ward off predators, acting as a form of aposematism, but also acts as camouflage, with the worms appearing brown from above (blending in with the substrate) and blue from the sides (blending in with the water).

(Images by Gert Oxby and Michel Garnier)

[nautilusgays]

Aronnax: Captain, would you still love me if I was a worm?

Nemo: Ah professor, love is difficult to predict; but, I promise you, were you to become a worm I would ensure you had the most comfortable life possible. Using the knowledge I have collected over the decades I would design and build a habitat that would provide you with the optimal conditions for your genus of worm; be it polychaete, echiuran, nemertean or other.

Aronnax: *heart eyes*

Ned: *loud disgusted noises*

--Later--

Ned, in his bunk: Conseil, would you still love me if I was a worm?

[animalshowdown]

Phylum Round 1

Nemertea: Ribbon Worms. These simple organisms are mostly seafloor-dwelling, but some may live in freshwater or even on land. Most are predators of small invertebrates, but some are herbivorous or symbiotic with a host. Instead of crawling, Nemerteans secrete a thick mucus and use thousands of tiny hair-like cilia to glide across the slimy surface. Their most distinctive feature is their internal proboscis, which can be everted inside-out of their bodies and used to capture prey.

Ctenophora: Comb Jellies. The largest animal phylum to swim using hair-like cilia. Their cilia are arranged in rows, called combs or ctenes, down the length of their body. The cilia move in a wave-like pattern that generates colorful reflecting light shows. Almost all Ctenophores are predators of small plankton as they drift in the ocean. They inhabit a variety of marine habitats from the coastal intertidal to the open ocean.

[bestanimal]

Round 1 - Phylum Nemertea

(Sources - 1, 2, 3, 4)

Animals in the Phylum Nemertea, commonly known as “Ribbon Worms” or “Proboscis Worms,” are small and mostly slim with a venomous proboscis that everts just above to mouth to capture prey.

There are about 1,300 known species of nermertean. Most nemerteans are carnivores, feeding on annelids, clams, and crustaceans. Some species are scarvengers. Some species are filter feeders that utilize a sucker at the front and back ends of their bodies to attach to a host. Most nemerteans detect the world through the use of chemoreceptors, but some species have simple eyes that allow them to distinguish light from dark. They move slowly, using cilia to walk on a trail of slime. Some larger species can “slither.” Many are brightly colored and patterned. Most nemerteans are marine, living in either the open ocean or on the sea floor, but some species are freshwater, and some are even terrestrial.

Propaganda under the cut:

Previously, nemerteans were split into two groups by whether they had a “little dagger” on their proboscis or not. (This classification no longer applies as one of the “unarmed” orders was closer related to the “armed” group than the rest of the “unarmed” group. It’s still fun to imagine worms with little daggers tho.)

The Bootlace Worm (Lineus longissimus) (seen in the first image) is one of the longest known animals, with specimens up to 55 m (180 ft) long being reported. This is longer than the Lion’s Mane Jellyfish, the sauropod dinosaurs Argentinosaurus and Patagotitan, and the record-holding longest Blue Whale. Like other nemerteans, the Bootlace Worm can also stretch up to 10 times its resting length. They’re not considered the largest animals though, because they’re only 5 to 10 mm (0.20 to 0.39 in) wide!

As a defense against predators, the Bootlace Worm produces a toxic mucus which contains a strong neurotoxin and smells faintly of “iron or sewage.” The mucus has been shown to kill arthropods, and is being studied for its use as a natural pesticide.

Some larger species can regenerate, breaking into pieces when disturbed, after which the fragments can grow into full individuals!

Some nemerteans have a branched proboscis that comes out as a “mass of sticky spaghetti” that can then be used to pull prey into its mouth. If you love horror movies, this is the animal for you! I’m not easily grossed out, but I genuinely can’t stomach this video, so viewer discretion is advised! (Thankfully, this one didn’t have a “little dagger.”

[sbnkalny]

Metres

[bethanythebogwitch]

There are some animals that, if they didn't exist and somebody made them up, we would say they had an overactive imagination. The bobbit worm is one of those creatures, the closest we have to a real-life Mongolian death worm. So for this Wet Beast Wednesday, I'll tell you about just how weird it is.

(image: a rare full-body shot of a bobbit worm)

Before we start, I want to go on a brief tangent. What exactly is a worm? Well it turns out that like fish, worms aren't real. At least they aren't from a taxonomist's perspective. In common parlance, we refer to any long, skinny, and (usually) legless invertebrate as a worm. In taxonomy, that is far too broad of a category, especially as lots of animal lineages would have started out as something a lot like a worm and you can't stop being what your evolutionary ancestors were. Instead, taxonomists classify worms into multiple distinct phyla that independently converged onto the worm body plan, including the platyhelminths, nematodes, nemerteans, and annelids. The bobbit worm (Eunice aphroditos) is an annelid, which are known for their multiple body segments. More specifically, it is a polychaete or bristle worm, which are known for having a pair of fleshy protrusions called parapodia on each body segment, which have chitinous bristles called chaetae growing from them. There is some debate that the bobbit worm may actually be a species complex, which is when multiple related species are mistakenly classified as a single species.

(image: a bobbit worm found in an aquarium)

Bobbit worms are the largest of the polychaetes, with the largest known specimen being 299 cm (9.81 ft) long. They are also rather skinny, usually reaching no more than 2.5 cm (1 in) wide. Bobbit worms have a wide range of coloration, ranging from brown to black and often with a rainbow of other colors going down their bodies. You might not notice this, however, because they spend most of their time burrowing under the sand in their Indo-Pacific coral reef habitats. This provides protection from predators and is important to their hunting strategy. Bobbit worms will stick their heads out of the sand and wait while their 5 antennae use chemosensitive and light-sensing cells to detect when fish pass by. When a fish comes too close, the worm strikes. They use a set of retractable jaws that are razor sharp and come together like scissors to bite the fish. This bit is strong enough to cut small fish in half. It is rumored that this is the source of their name, from the Lorena Bobbit case. I will not elaborate further, google it if you don't know. Those fish that are not killed immediately will find themselves bleeding out and paralyzed from venom injected through the jaws as they are dragged into the worm's burrow to be eaten. There are some reports that the wom's chaetae are also venomous and that handling them barehanded can cause permenent numbness, but this does not appear to be the scientific consensus. The worms will also feed on seaweed and other algae, making them omnivorous.

(gif: a bobbit worm catching a fish)

The borrows made by bobbit worms are dug out of the sediment and coated with mucus. The worm uses its chaetae to move in and out of the burrow. The mucus if filled with nutrients that bacteria, particularly sulfate-reducing bacteria, absolutely love. This allows iron sulfides to accumulate in the mucus. When exposed to oxygen in the water, usually at the opening of the burrow, the sulfides will become iron hydroxides. These help reinforce the burrow's opening. Bobbit worms rarely leave their burrows and will retreat at the first sign of danger, making it very hard to spot them in the wild. Several fossilized burrows have been found, one dating to 20 million years ago. Another burrow of a similar animal, possibly an ancient relative of the bobbits, was found dating to 400 millions years ago.

(image: a bobbit worm head with jaws extended)

Bobbit worms reproduce externally. At night, a female will emerge from her burrow and release pheromones that attract males. She will then release her eggs into the water. The males will follow by releasing sperm, allowing for fertilizations. The majority of larvae will die before reaching adulthood. There are rumors that females withh bite off the male's genitals to feed to her young, but this is not true. Bobbit worms can also reproduce asexually by splitting. When handles, a bobbit worm can split itself into multiple sections, each of which can grow into another identical worm. This is a common adaptation in polychaetes as it allows them to survive if a part of them is eaten.

(image: a bobbit worm just sitting there, menacingly)

Bobbit worms have become a nuisance species in aquariums. They are usually introduced as tiny larvae clinging to rocks brought in for decoration or shelter. Once in an aquarium, the worms can grow rapidly and will eat any fish in the tank. Removing them can be very difficult due to their size, regenerative abilities, and reclusive nature. One famous case that introduced a lot of the internet to the worms was that of the Newquay aquarium in England. Aquarium staff were confused when a lot of the fish were vanishing from one tank and the coral was damaged. They tried laying traps, but the intruder ate the fishhooks they used and could bite through 20 lb fishing line. Finally, they lured it out with food, finding a 4 foot long bobbit worm that they named Barry. Barry became a hit online and was moved to his own tank. There apparently were plans to put him on exhibit, but I can't find confirmation that this ever happened. Given that this happened in 2009 and the bobbit worm lifespan is 3-5 years, I am sorry to tell you that Barry has passed away. RIP, king.

(image: Barry after being removed from the tank. His drab color is thought to be the result of poor nutrition)

Because of how reclusive they are, bobbit worms are an understudied species. Attempts to raise them in laboratories have mostly failed, so there is a lot we don't know about their reproduction, development, and behavior. We also don't know if they need any conservation efforts.

How many times in this series am I going to be able to use cards from this series? (image: the bobbit worm card from Weird n' Wild Creatures)

[mbari-blog]

Our most recent addition to the deep-sea-animals-you've-never-heard-of collection—a pelagic ribbon worm, Phallonemertes sp.⁠

Nemerteans are neither worms nor fish, although they look a bit like both. They are unique enough to belong in their own phylum. Most nemerteans burrow in sediments or between crevices in rocks, shells, and other seafloor habitats, but some, like this one, live in the open ocean, never touching the seafloor.

Nemerteans range in length from a few millimeters to 30 meters stretched (nearly 100 feet) in length (most species commonly measure about 20 centimeters, just about eight inches, or less).

[mukuberry]

oh worm... 🪱

Worms are many different distantly related bilateral animals that typically have a long cylindrical tube-like body, no limbs, and usually no eyes.

Worms vary in size from microscopic to over 1 metre (3.3 ft) in length for marine polychaete worms (bristle worms) 6.7 metres (22 ft) for the African giant earthworm, Microchaetus rappi and 58 metres (190 ft) for the marine nemertean worm (bootlace worm), Lineus longissimus. Various types of worm occupy a small variety of parasitic niches, living inside the bodies of other animals. Free-living worm species do not live on land but instead live in marine or freshwater environments or underground by burrowing.

In biology, "worm" refers to an obsolete taxon, Vermes, used by Carolus Linnaeus and Jean-Baptiste Lamarck for all non-arthropod invertebrate animals, now seen to be paraphyletic. The name stems from the Old English word wyrm. Most animals called "worms" are invertebrates, but the term is also used for the amphibian caecilians and the slowworm Anguis, a legless burrowing lizard. Invertebrate animals commonly called "worms" include annelids, nematodes, flatworms, nemerteans, chaetognaths, priapulids, and insect larvae such as grubs and maggots.

The term "helminth" is sometimes used to refer to parasitic worms. The term is more commonly used in medicine, and usually refers to roundworms and tapeworms.

[statecryptids]

More speculative radiodonts! Opabinia-relatives in this case.

Much as they are today, freshwater mussels were common in many rivers throughout the world where the constant flow of water provides a steady supply of nutrients. Here we have two species of Devonian-era freshwater opabinids that live among the mussel beds. The Banquet Guest (Ostrinduendum conviva, “Mussel-wearing banquet guest”) spends most of its life inside the shell of a mussel with its long proboscis extended into the water column. The end bears long, fine setae which it uses to filter feed. Outside the shell, the Banquet Guest is a bottom dweller.

The Fetch Opabinia (Doppelganger bamini) is an ambush predator. Its striped proboscis resembles a species of nemertean worm common to the mussel beds. The Fetch spends most of its time hiding in a bivalve shell with this proboscis waving in the water. The worms, which prefer to aggregate in groups within mussel shells, are lured in by this decoy and devoured by the opabinid. The lure is also used as part of the opabinid’s reproductive cycle. A female will wave her lure to attract predatory fish and once the vertebrate gets close enough, she will squirt it with a slimy packet of eggs that adheres to its gills and scales. When the eggs hatch, the young opabinids continue to cling to the fish until they mature and drop off in a new part of the river.

The name “Fetch” refers to a spirit from Irish folklore that appears as the double of a person about to die. The doppelgänger is a similar entity from German folklore, hence the Genus name. The species name banimi honors 19th century Irish writer Michael Banim, whose short story “The Fetches” featured these spirits.