#phylliroe

[spuddragon]

Phylliroe sea slug dragon!

[arsenic-green]

 Phylliroe bucephalum, a species of parasitic nudibranch

[eddie-roo]

I love Carinaria and Pterotrachea snails. These little planktonic pelagic carnivorous sea snails are just so silly. Little bumbling crystalline shelled worms with a floppy fin and a trunk, they're so special to me.

I found out about their existence when looking into swimming gastropods for a spec bio project. Phylliroe was the gateway slug to a world of wonderfully whimsical swimming little fellas, like Aplysia sea hares and the closely related royal flush slugs.

I've made a little playlist full of these silly little guys and some others.

https://youtube.com/playlist?list=PLTkLI31yRn9OcbRvuSXPhZ5x7d0rokFj8&si=aLHyYDu00HvWc_Qg

[seaslugger]

2023 seaslugs. Year of the seabunny.

A quick New Years 🎊 pic with some chibi nudibranch merfolk.

A seabunny (jorunna) brings in the new year, flanked by Phyll and Glaucer. Not great but at least I posted something quick to kick this year off.

Year of the (sea)rabbit. May the improvement commence.

Have a great new year! 🎉

[otherworldy-insect]

OKAY SO RAHHH I WANTED TO MAKE AN OC FOR @werewolfsister’s DIPLOMAT THING BECAUSE I DONT HAVE ENOUGH ZORA OCS…. (been thinking abt aus too much) BUT UHH HERES MY OC!!!

orre is based on a nudibranch!!! not a specific one but they are VAGUELY inspired by a phylliroe bucephala sea slug and other things (mainly the fishlike appearance)

[quark-nova]

Didn't keep some from trying

Joke fringe theory: birds are polyphyletic

I have absolutely no idea what this word means and the only thing I can think is "birds are... prophylactic?"

Please define this term so I can stop thinking about bird-condoms 😭

SO

Monophyletic: A group of organisms that includes an ancestor and all of that ancestor's descendants. This is also known as a "clade". Basically, a single evolutionary unit. This is the only one of these three words that is "real" in the sense of anything being real.

Paraphyletic: A group of organisms that includes an ancestor and some, but not all of that ancestor's descendants. "Nonavian Dinosaurs", or "Non-Tetrapod Fish" are both paraphyletic groups. This is also known as a "grade". It is a partial evolutionary unit, but not a whole one.

Polyphyletic: A group of organisms that are not closely related to each other, ie, they do not share a recent common ancestor. This would be like trees - trees just keep evolving over and over again, rather than just the once. It is not an evolutionary unit in the slightest.

Visualizations:

[marinebiology1]

sea slug

genus Phylliroe

[archipithecus]

Fish Taxonomy

The term fish is commonly used to refer to members of Actinopterygii (ray-finned fish, mostly what people think of when they imagine fish)and Chondrichthyes (cartilaginous fish, the sharks, rays, etc, and chimeras). It is also used for Sarcopterygii (lobe-finned fish, the coelacanths and lungfish) and Agnatha (jawless fish, the hagfish and lampreys), although people don’t talk about lobe-finned and jawless fish as much as they do ray-finned fish and sharks. Tetrapoda (four-limbed vertebrates) is nested within Sarcopterygii, and mostly contains animals which traditionally have not been considered fish (you, me, your cat, the chicken eating your popcorn, the frog hopping away from the chicken). In modern cladistics, this is a little bit of an issue, because the common use of fish as described above is paraphyletic, i.e. it does not include all of the descendants of the group’s last common ancestor. Here are some different ways this issue can be resolved. 

Option 1: Fish is not a cladistic term, and therefore we don’t need to worry about whether it’s a good and well formed clade. Reasonable and understandable, we have loads of scientific terms to unambiguously talk about groups of animals, but also boring. Play with me in this space!

Option 2: Fish includes Osteichthyes (Actinopterygii plus Sarcopterygii), Chondrichthyes, and Agnatha, therefore it is essentially synonymous with Vertebrata. You, me, and Moby Dick are all joyfully fish (Melville was right!) (and also a fish). Is this really helpful? Maybe not, but it’s fun. 

Option 3: Fish is not a cladistic term, it’s a non-scientific term used to refer to any animal that lives in the water. Jellyfish are fish, starfish are fish, dolphins are fish, humans are not fish, why would you ever suggest such a silly thing?

Option 4: Fish is essentially synonymous with Vertebrata, so why not expand that to all of Chordata? Tunicata and Cephalochordata are welcomed into the Fish Club. 

Option 5: Fish is a lifestyle. In the same way that a tree is any plant that gets tall and kinda woody, a fish is an obligate aquatic animal that actively swims. Salmon are fish, tadpoles are fish, frogs are not fish, sea stars are not fish, porpoises are fish, octopuses (-pi, -podes) are fish, most gastropods are not fish, but Phylliroe is absolutely a fish. 

Option 6: Fish comes from the Proto-Indo-European root *peysḱ-  (“fish”), which is probably derived from *peyt- (“to feed, to guard, to nourish”), and is cognate to lots of words having to do with food (Sanskrit पितु (pitu, “food”), Lithuanian piẽtūs (“lunch”), etc), so if someone asks you “is this a fish?” you must slap it on the grill, maybe squeeze some lemon on it, and find out for yourself. 

[spearxwind]

I saw a video of a Phylliroe swimming in its fancy little way on twitter and it made me think of you ⋆｡° ✩彡

Oh WOW!!!! What a spectacular creature!!!! That is genuinely so cool thank you for showing. And ty for the link to the source as well, thats stunning, im gonna be thinking about these for a while, convergent evolution is so cool

[cosmicplanarian]

100 Days of Sea Creatures Day 17 - Phylliroe

These pelagic sea slugs have convergently evolved the classic fish shape in order to swim effectively through their open-ocean habitat

[craftingcreatures]

Pelagic Nemerteans with convergently fishlike body shapes?! This is like Phylliroe sea slugs all over again

While looking for more info on this guy I also found Nectonemertes, which even has a swimmy little tail! (B and C in the figure below)

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).

[gacorley]

can you elaborate on that sea slug?

Say hello to Phylliroe

Image source.

It's a genus of sea slugs that has adopted a similar outer body plan to a fish as it evolved to hunt in the open sea.

Look at that! It looks like a transparent fish, but it's a sea slug!

(I believe I learned about this either through Tumblr or through Biblaridion's Alien Biospheres series.)

[vintagewildlife]

Phylliroe nudibranch By: Peter M. David From: Deep Oceans 1971

[mercurialbadger]

Phylliroe bucephalum are a majestic sea slug that use their fins to swim like any fish

457 METERS DEEP

Fuck that thing Iguess

[anudibranchaday]

Phylliroe is a genus of nudibranch that actually swims to catch its prey: jellyfish-like hydromedusae. It grows 5cm long, and different species are found in the tropical Atlantic and Pacific oceans, and the Mediterranean sea. If you think it looks like a fish, you're not alone; this nudibranch is considered an example of convergent evolution, evolving similar swimming mechanisms to fish - which you can watch in this video. One more quirk of this genus: it glows (bioluminesces)!

Photo source

[just9art]

something I felt like making