#lancelet

[inkyami]

Lancelet Illustration for the new edition of "The Mists of Avalon"

Nimue Morgaine & Mordred

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#arthuriana #arthurian mythology #the mists of avalon #lancelet #lancelot #dragon #celtic

[bethanythebogwitch]

The modern world is nice, but sometimes you just get the urge to go primitive. Because I'm a complete wimp who would die within a day of giving up the internet, I'm going to deal with that urge by talking about primitive animals. It's Wet Beast Wednesday and I'm talking about lancelets.

(image: a lancelet. Not much to look at, are they?)

Lancelets, or amphioxi, are highly basal (close to the ancestral form) chordates that are vaguely similar to fish, but are vastly more primitive. They have all the characteristics of chordates, the key one being a notochord, a flexible rodlike structure that goes down the body. The majority of chordates that are still alive are vertebrates, who have incorporated the notochord into the spinal column. The other groups of surviving chordates are the tunicates (who I'll get to eventually) and the lancelets. Because lancelets are so primitive, they are used at model organisms representing an early stage of vertebrate evolution. It was originally thought that lancelets are remnants of an early lineage that eventually evolved into vertebrates. Genetic studies later showed that tunicates are actually more closely related to modern vertebrates than lancelets. They are still used as a model organism as they are a fantastic representation of early chordates. The similarity of lancelets to the 530 million year old Pikaia gracilens, one of the earliest known chordates, is one of the reasons they are such a useful model organism.

(image: a diagram of lancelet anatomy by Wikipedia user Systematicist)

Lancelets can be found all over the world, living in temperate to tropical shallow seas. The only known exception is Asymmetron inferum, which has been found around whale falls at 225 m (738 ft) deep. They are small animals, reaching around 8 cm at their largest. An amphioxus looks pretty worm-like, with a simple mouth at one end and a pointed tail at the other. The name amphioxus means "both (ends) pointed" which is a pretty appropriate description. The mouth is lined with tentacle-like threads called oral cilli, which are used for feeding. Lancelets are filter-feeders that use the cirri to filter plankton, microbes, and organic detritus. Water and food pass into the pharynx (back of the mouth), which is line with gill slits. This is where it gets weird. The gill slits aren't used for respiration, but for feeding. Mucus gets pushed through the gill slits by cilia, trapping the food and moving it deeper into the digestive tract. Not only to lancelets not use their gill slits to respirate, they actually don't have a respiratory system at all. Instead, they just absorb dissolved oxygen through their thin and simple layer of skin. Their circulatory system doesn't move oxygen around either as there is no heart or hemoglobin present. For what it's worth, they don't have a proper live either. When you look at a lancelet's anatomy, you can see similarities to fish anatomy, just much more primitive and with some parts missing.

(image: the head of a lancelet, with mouth and cilli visible)

Lancelets have 4 different systems used for vision. Two, the Joseph cells and Hesse organs, are simple photoreceptors that are on the notochord and detect light along the back of the animal. Imagine having a bunch of very simple yes on your spinal cord that can see through your skin. There is also a simple photoreceptor called the lamellar body (which confusingly is also the name of a type of lipid) and a single simple eye on the head. Speaking of light, lancelets are florescent, producing green light when exposed to blue to ultraviolet light. In all species, the proteins responsible for this are found around the cilii and eye, but some species also have them in the gonads and tail. The purpose for this florescence isn't exactly known, but a common hypothesis is that it helps attract plankton toward their mouths.

(image: an extreme close-up of a lancelet's cilli fluorescing)

Lancelets have seasonal reproduction cycles that occur in summer. Females release their eggs first, followed my males releasing sperm to fertilize them. Depending on species, spawning can either occur at specific times, or gradually throughout breeding season. Development occurs in several stages. In the frist stage, they live in the substrate, but they will quickly move into the water column to become swimmers. These swimming larvae practice diel vertical migration, traveling to the surface at night and returning to the seafloor in the day. While larvae can swim, they are still subject to the current and can be carried long distances. Adults retain their ability to swim, which is done by wriggling like an eel and in some cases, spinning around in a spiral fashion while moving forward. Unlike the larvae, adults spend most of their time buried in the substrate with only their heads exposed. They typically only emerge when mating or if disturbed.

(image: a diagram of the lancelet life cycle. source)

Because of their use as model organisms, humans have developed methods to keep and breed lancelets in captivity. The majority of research has been done on Branchiostoma lanceolatum, but several other species have been studied. Multiple species are endangered due to pollution and global warming. Several species are edible and can either be eaten whole or used as a food additive. In spring, when their gonads begin to develop for breeding season, they develop a bad flavor.

Mom: "we have garden eels at home". Garden eels at home:

(image: three lancelets sticking their heads out of the sediment)

#wet beast wednesday #weird-ass tube beast #lancelet #amphioxus #chordate #chordata #marine biology #biology #ecology #zoology #animal facts #evolutionary biology

[forms-and-phyla]

Phylum #8: Chordata!

A notochord under a hollow nerve cord, pharyngeal slits and a post-anal tail. United by a simple but elegant body plan, chordates nonetheless became one of the most diverse phyla in the animal kindom. While the small filter-feeding lancelets closely preserved the original chordate body plan, tunicates and vertebrates would reshape it in unexpected ways, with new materials gained through evolution.

Tunicates achieved the unique ability among animals to synthesize cellulose. Tadpole-like larvaceans build submarine-like "houses" with complex sets of filters to collect food particles. Other tunicates, after a drastic metamorphosis, abandon the notochord and fully integrate cellulose tunics as their body walls, often merging them together in massive colonies.

Meanwhile, vertebrates built upon the original notochord, housing it in a solid skeleton of cartilage or bone. With this, vertebrates could not only reach land, but even conquer the skies, with three out of the four flying clades in animal history being vertebrates (birds, bats and pterosaurs).

Their internal skeleton providing both support and flexibility, vertebrates have dominated megafauna for more than 300 million years. Especially on land, they brought animal life to scales previously unheard of: at 70 tons, Argentinosaurus weighed 200 times as much as the largest invertebrate to ever walk land, Hibbertopterus.

#forms and phyla #chordata #vertebrate #tunicate #lancelet #marine biology #fishblr #paleoblr #ellie

[vintagewildlife]

Lancelets (Branchiostoma sp.) By: Heather Angel From: The Complete Encyclopedia of the Animal World 1980

#lancelet #1980 #1980s #Heather Angel #The Complete Encyclopedia of the Animal World (1980)

[sillyghostsstuff]

Lancelets diversity.

1. Shrimp analog. Fastening with its jawlegs to the sea bottom, it scrapes algae (and only to) with its tonguelegs.

2. Salmon-like lancelet. Like a shark, it patrols the bottom of river and lakes in search of food. It can both filter water and catch bottom animals.

3. Long carnivore lancelet, who lives in sand.

4. Filter feeding lancelet.

#art #inkart #sketch #speculative biology #inkdrawing #speculative zoology #biology #speculative #evolution #lancelet #creature

[macattackz]

LANCELOT THE SILLIEST KNIGHT AROUND

ALSO THE ONE THAT REALLY LIKES GUINEVERE LIKE-

this post is deticated to @reallancelotfan01 😎

#arthur king of cyberlot #arthurian legend #knight #knights #art #myart #ref #character design #cyber knights #arthur #king arthur #lancelot #lancelet #sir lancelot #sir lancelet #lancelot du lac #sir lancelot du lac

[vickysaurus]

The strange creatures in these jars are relatives of ours! They're chordates, which means they share our basic body plan with a spinal chord running the length of the body. Unlike us, fish, reptiles, and all other vertebrates, however, they don't have any bones. The ones in the bottom picture are lancelets, and they look exactly how you'd expect from that description: little featureless fish/tadpole creatures. The tunicates in the top picture, however, took a very different path than the rest of us chordates: the adults are sessile filter-feeding bags. Their larvae, however, swim around and look a lot like the lancelets before they find a good spot to anchor themselves and change into their adult form.

#tunicate #lancelet #chordate #cw: animal death

[who-is-kim]

hello tumblr can you show me the funny posts

#thank you #fluttershy #lancelet #pinkerton #the ingot i ate it

[switch]

i don’t know how to ask this in a way that doesn’t make me sound like a tool so i’m just gonna ask:

why is oberon’s ascension unlock fight considered so difficult? nothing raised big red flags when i was reading about it, and i 3 turned it in one attempt with my moriarty which made me disappointed with how easy it felt so i never uploaded it. i don’t not believe you all i just feel like i’m missing something.

#switch speaks #there have been a handful of ‘felt too easy’ esports casualties for me the past year #barg and lancelet were others #fate//

[tale-of-two-new-kings]

"The tale of two new kings" - [Intro. post⚔️🛡️]

[All OOC (out of character) posts and tags will be made in brackets like this one. All basic DNI rules. Anons allowed; if your rude or spam you will be blocked]

[Hello! My name is Deerly and my main blog is @deerdeardarling where I mainly post about my Pokemon Chosen AU, which this blog is apart of! As well as all of my other hcs & aus. This blog is specifically around my version of The First Two Galarian Kings! who were only crowned a year ago.]

[These two are Tarax (right) and Lancelet (left)! They are the original Chosens of Zacian and Zamazenta and are around 16 years old. Tarax is very spry and tries to be uplifting and positive even in times of uncertainty; while Lancelet (or just Lance) is more reserved and quick witted (this. will very likely not show well in my writing. cause i am not smart lmao)] [Note: I'm gonna try to use like. ye olde speak but really no guarantees. Really this is all just for fun and so I can share my ideas. Also blog lore will be in another post after this one initial one]

#pokemon rp #pokemon irl #[i guess?] #pokeblogging #pokemon sword and shield #pkmn swsh #[what else do i tag this???] #King Tarax #King Lancelet

[mhaccunoval]

i wish we had more chordates that retained chordate synapomorphies into adulthood :(

#pant rambles #i think it's awesome that lancelets do #but i need More creechur (<- wants to Make creechur) #edit: okay lampreys retain them too but STILL. i want limbed creechur...

[deerdeardarling]

Battle teams and leasure teams for Tarax & Lancelet!

Socialite vs Bookworm lol

#pokemon sword and shield #pokemon oc #oc: tarax #oc: lancelet #first galar kings

[vintagewildlife]

Immature lancelet By: Unknown photographer From: Natural History of Marine Animals 1949

#lancelet #1949 #1940s #Natural History of Marine Animals

[inkyami]

Illustration for the new edition of "The Mists of Avalon"

Nimue Lancelet Morgaine & Mordred

Twitter | VK | INPRNT | Leave a tip

#artists on tumblr #medieval #arthuriana #celtic #the mists of avalon #mixed media

[sporesgalaxy]

hey check this shit out

the lancelet ☝️

#adddna #biology

[fishyfishyfishtimes]

What Is and Isn't a Fish: a List

A list of the animals I discussed in my fish essay, but for those who don't want to scroll through paragraphs of text to find out if an animal is or isn't a fish. Just CTRL+F your way through here!

I'll add onto here more animals whenever I get asked about them being fish. See my fish essay here!

Some notes before you proceed:

Yes, all tetrapods are fish! We are phylogenetically fish, as we are and our ancestors were lobe-finned fish! "Fish" in the phylogenetic sense is a paraphyletic group if you try to exclude tetrapods, so it is frankly impossible.

How come tetrapods aren't listed as fish then? Long answer, read my essay. Short answer, me and other fish accounts tend to operate on the morphological definition of fish, so does most of the world. Here I use the morphological definition of "fish".

Fish:

Jawless fish

Hagfish

Lamprey

Cartilaginous fish

Sharks

Dogfish

Whale shark

Chimaeras/Chimeras/Ghost sharks

Ratfish

Ray

Stingray

Skate

Ray-finned fish

Teleosts

Catfish

Eels

Moray eel

Seahorse

Sea dragon

Lobe-finned fish

Coelacanth

Lungfish

Not Fish:

Crustaceans

Krill

Shrimp

Crab

Crayfish/Crawfish/Crawdad

Lobster

Spiny lobster

Triops

Mantis shrimp

Barnacle

Isopod

Copepod

Shellfish

Mollusks/Molluscs

Gastropods

Sea snail

Sea slug

Snails and slugs in general

Sea angel

Sea hare

Sea bunny

Cephalopods

Octopus

Squid

Cuttlefish

Nautilus

Inkfish

Bivalves

Clam

Mussel

Scallop

Oyster

Chiton

Chelicerates

Horseshoe crab

Sea spider

Water mite

Diving bell spider

Cnidarians

Jellyfish/Sea jelly/Jelly

Coral

Sea anemone/Anemone

Siphonophores

Portugese man o' war

Echinoderms

Sea cucumber

Sea pig

Feather star

Sand dollar

Sea biscuit

Sea cookie

Brittle star/Serpent star

Sea urchin

Starfish/Sea star

Comb jelly

Lancelet

Tunicates

Sea squirt

Salp

Annelids

Bristle worm

Bobbit worm

Spoon worm

Giant tube worm

Bone-eating worm

Sea mouse/Sea mice

Feather duster worm

Christmas tree worm

Leech

Flatworm

Amphibians

Salamander

Amphiuma

Mudpuppy/Mud puppy

Waterdog

Olm

Axolotl

Siren

Frog

Toad

Tadpole

Caecilian

Reptiles

Sea snake

Water snake

Snakes in general

Sea krait

Turtle

Snapping turtle

Softshell turtle

Sea turtle

Terrapin

Marine iguana

Crocodilian

Crocodile

Alligator

Caiman

Gharial

Bird

Penguin

Seagull

Loon

Swan

Mammals

Whale

Orca

Baleen whale

Toothed whale

Dolphin

River dolphin

Porpoise

Narwhal

Beluga whale

Sperm whale

Pinniped

Seal

Sea lion

Leopard seal

Elephant seal

Walrus

Sirenian

Manatee

Sea cow

Dugong

Otter

Sea otter

Beaver

Hippo

Platypus

Muskrat

Water shrew

#fish guide #fish essay #marine biology #fish #fishfact #fish facts #biology #zoology #long post