linruuu

Latest Posts by linruuu

spiny lobster conga line😎

this is the saddest fucking thing. wheres that post about when you cant even write a poem about it because its just there already

Genus Brachycybe

A true friend is seen in times of need...

👀

Parasitic crustaceans are wild.

[cw: photos of parasites inside host bodies]

Here is Linguatula serrata, which lives inside the nose of dogs and other Carnivorans. It belongs to group Pentastomida, which has so shed its arthropod appendages that it was long classified as its own independent phylum (attested in fossils all the way from the Cambrian Explosion!), until molecular analyses showed they were in fact strange crustaceans – closest relatives of the relatively normal-looking fish lice (Branchiura).

And then there’s Pennellidae…

Do those horn-things look like crustaceans to you? And yet the family Pennellidae is fully part of Copepoda, the chief component of crustacean plankton. Its body is simply one elongated trunk and a tiny head biting onto the fish, with two long egg cords trailing behind.

Look at the cod worm (Lernaeocera branchialis), another Pennellidae, hanging from the gills of a fish:

It’s those two red things that look like slugs wearing a wig made of soy noodles. Here’s what it looks like on its own, extracted and preserved:

(source) The coiled strings are egg masses. The slug-like part is the copepod’s trunk. The thin branching thing at the bottom is its head, converted into a sort of root system that no longer does head-like things, but rather burrows into the fish host’s blood vessels to feed its eggs. Incidentally, this is just the female; the male still looks like a regular planktonic crustacean.

Now, regular barnacles (Cirripedia) are strange enough…

(source; picture them as shrimps lying on their back, with a digestive system that fell out of the body wall but is still contained by the outer shell, and feathery legs poking out to filter water)

… but parasitic barnacles of clade Rhizocephala go much further:

Here, on the left, is Sacculina carcini. No, not the crab; the yellow sac poking out of the crab’s belly. On the right, its relative Clistosaccus paguri shows what it might look like once extracted.

Sacculina carcini is fun. A larva looks much like any other crustacean planktonic larva, until it finds a suitable host. It stings the unfortunate crab in a vulnerable spot between armor plates, and effectively injects itself into the host, leaving its own shell outside, and transferring only soft tissues.

Once inside, it grows more like a fungus than an animal, turning into a root-like web that infests the crab’s entire body, down to its leg tips. Then it takes over not only the crab’s digestive system, leeching nutrients for its own eggs, but also its nervous system, effectively controlling it like a puppet.

When the parasite is mature, its egg sac starts bulging out of the crab’s body: that’s the yellow part you see in the photo. Male Sacculina stay larvae their whole life: they just mate with the female’s egg sac and then die. The parasite makes the crab take care of itself as if it was the crab’s own eggs. There’s no competition, since the host is sterilized; to leave more food for the parasite, it also stops molting and regenerating lost limbs. If the host is male, and therefore poorly suited to carrying egg sacs under its tail, Sacculina messes with its hormones and effectively turns it female.

Finally the eggs are released and the whole cycle starts again, with the only purpose of making more eggs whose purpose is making more eggs.

(all pictures from Wikipedia unless specified otherwise)

A sturgeon is a fat little man that i care for dearly and also the most beautiful woman in the world

i am afraid of what tiktok is doing to people's view of sharks.

i love sharks. i am obsessed with sharks.

and i'm glad that the "jaws" view of sharks is fading. but it worries me that people are saying things like "sharks are literally just ocean puppies". no, they're not as dangerous as a lot of people think, but they're still wild animals. do not treat a shark like a puppy. i've seen videos of people getting themselves bitten by nurse sharks. if you know anything about nurse sharks, then you know that these people were really harassing them. they're not monsters, but they're not your friends either. they're animals who will lash out if they're antagonized or crowded.

anyway sharks are still adorable and i love them very much

I know there's a niche in ecology for organisms that climb on other organisms and eat their parasites. Are there any examples in nature of creatures mimicking other more beneficial organisms?

There's probably more examples than we know of but oddly the only one I've ever heard of are the false cleaner wrasses! Real cleaner wrasses perform a "dance" that "advertises" to fish of countless other species that they'll eat their parasites, so other fish will respond to the dance by hovering in place and spreading their fins to be cleaned up.

The false cleaner wrasse mimics the coloration, shape, and dance of the real thing but then eats chunks of actual fin. It also has a silly face that opens up into demon fangs:

smilin about it!! thinks its funny!!!!

photos from: 1, 2, 3

every moment of every day i am thinking about this tiktok

tried to google search for that post that's like.. something about squids and it goes "the squirterrrrrrrrr" and believe it or not that did not show me the thing i was looking for

one of the best academic paper titles

Algal pun valentines part 2. Enjoy!

One of my favorite things about biology is that there are so many diagrams like this that look like shitposts if you remove any and all context from them

There were a lot of freshwater mussels on the 2021 US extinction list. They didn’t leave us with haunting recordings of them calling out for a mate they’d never meet, there were no drawings in vivid color. They were extremely important nevertheless and their loss is frustrating too. That’s why stream ecology and mollusks have always fascinated me. They were silent, stalwart little heroes and entire species were lost to pollution.

Today we learned that conches, the sea-dwelling mollusks who live inside those big, beautiful conch seashells in warm tropical waters, peer out at the world with cartoonish eyes on tiny eyestalks. They see you. They see everything. And what’s more, they can regenerate their peepers should they happen to lose one or both of them.

“One 1976 paper dug into the specific behind these animals’ alien eyestalks. Sitting at the tips of long stalks, they contain retinas with both sensory cells and colored pigment cells. But the story gets weirder because obviously, it gets weirder. After amputating the conchs’ eyes, a fully-formed replacement took its place 14 days later. Humans, we really are losing this evolutionary game.”

But wait, that’s hardly the only surprising set of eyes under the sea. Scallops have eyes too, LOTS of them:

Conch photos by Redditor buterbetterbater and via @shingworks.

[via /r/pics and Gizmodo]

The Sea Angel (Gymnosomata) Is a group of sea slug that grow no larger than 5cm. These obscure little creatures are found in a wide range of habitats from polar to tropical regions of the sea. 

i exist, i exist, i exist

kačka chmelíková // holly warburton // ? // image from pinterest // letters to a young poet by rainer maria rilke

Real Isopod Facts

please watch this i love him

Ok so, here’s a funky fact: in the early evolution of fish, the claspers (reproductive organs still present in modern sharks) actually began as a genuine third pair of limbs. Sooo what if instead of becoming purely reproductive, the claspers instead developed into full on legs.

Basically what I’m saying here is six-finned fish -> hexapedal early tetrapods -> hexapedal temnospondyls -> hexapodal tiny weirdo arboreal dendrerpetids that develop membranes to glide -> amphibian dragons

they have little grabby hands and spurt venom out of their mouths and they are my precious new babies

Baby armadillo plays with his toy

This Trilobite walked 6 inches 600 million years ago to send us all a dick pic

“Meet the Shame-faced Crab”

Thank you, I will!

hey bunjy, would you happen to have any cursed (or blessed) facts about hummingbirds? saw one in my garden yesterday and they've been on my mind

contrary to popular belief, hummingbirds can open their beak all the way just like other birds can!

it's...

hm.

I don't wike it :(

Cat dimension