#Pumping water over gills!!!!!!!

[pep-the-artemis]

shout out to disabilities which only exist in fantasy.

Robots who carry around heavy battery packs because there inbuilt ones can no longer hold enough charge.

Shark girls who have pumps over one of there gills because they can't continuously swim fast enough to receive enough water through there gills.

bird girls with prosthetic wings.

creature wearing climbing gear because they were born without the ability to telepathically fly around.

Peridot

non-telepaths (in a world of only telepaths) constantly having to explain to angry people berating them because they assumed that the person is a telepath.

They both add a depth of realism to a universe and another perspective for abled bodied audiences to understand what its like to be disabled and are also fun.

[bestanimal]

Round 2 - Chordata - Chondrichthyes

(Sources - 1, 2, 3, 4)

Chondrichthyes is a class of jawed fish, commonly called “cartilaginous fish” due to their skeletons composed mainly of cartilage, making them distinct from all other vertebrates. They are comprised of the superorders Selachimorpha (“Sharks”), Batoidea (“Rays”), and Holocephalimorpha (“Chimaeras”).

Chondrichthyans breath through gills but lack opercula (gill coverings) and swim bladders. They have paired fins, paired nares (nostrils), and placoid (tooth-shaped) scales (except for electric rays, which have loose, soft skin). These placoid scales, also called dermal denticles, provide protection and streamlining, giving the animal’s skin a sandpaper-y feel. All chondrichthyans breathe through five to seven pairs of gills, depending on the species. As a general rule, pelagic species usually must keep swimming to keep oxygenated water moving through their gills, while demersal species can actively pump water in through their spiracles (a small hole or slit behind each eye) and out through their gills. Most larger, pelagic species no longer have spiracles. Chondrichthyans have many sensory organs to perceive the world around them. Their nostrils are attached to powerful olfactory organs. Around their face are a network of electroreceptors called Ampullae of Lorenzini, which allow them to sense electrical fields. Their lateral line has modified epithelial cells which sense motion, vibration, and pressure in the water around them. However, their sound-detecting apparatus has limited range and is typically more powerful at lower frequencies. Some species have electricity-producing organs which can be used for defense and predation. Chondrichthyans have a diverse array of shapes and sizes, ranging from the 10 cm (3.9 in) long, electric Finless Sleeper Ray (Temera hardwickii) to the over 10 m (33 ft) long Whale Shark (Rhincodon typus). All species are carnivores: some predatory, some ambush-hunters, and some filter-feeders. At least one species is omnivorous. Chondrichthyans have internal fertilization and most species give live birth, while some lay eggs. There is no parental care after birth, though some chondrichthyans do guard their eggs.

Chondrichthyans are considered to have evolved from Acanthodians, which appear from the Early Silurian. The first sharks began to evolve in the Devonian Period, though, while often claimed to be relatively unchanged, modern forms did not start appearing until the Early Jurassic.

Propaganda under the cut:

Mentioned briefly above, the Bonnethead Shark (Sphyrna tiburo), a small species of hammerhead, is the only shark known to be omnivorous. While it feeds on crustaceans, molluscs, and small fish, it also ingests large amounts of seagrass, which has been found to make up around 62% of gut content mass.

Also mentioned briefly above, Electric Rays (order Torpediniformes) are known for being capable of producing an electric discharge, ranging from 8 to 220 volts, depending on species, used to stun prey and for defense.

There are over 500 different species of sharks, and only a dozen could be considered dangerous to humans. That being said, of those 12, most do not seem to like the taste of human flesh, and bites are usually accidental or exploratory.

Many pelagic chondrichthyans occasionally breach, leaping out of the water. This can be done for hunting purposes, as a mating ritual, to shake off parasites, or even just for fun!

Today, all species of Sawfish (family Pristidae) are critically endangered. However, they were relatively common in the Cretaceous, where they were likely a common food source for Spinosaurus.

(Confusingly, Sawfish are a type of ray while Sawsharks (order Pristiophoriformes) are a type of shark. Sawsharks live in the deep sea and are rarely seen, while sawfish live in coastal and brackish waters.)

Kitefin Sharks (family Dalatiidae) have bioluminescent organs which glow blue in the dark

Chimaeras have a strange pair of teeth in their lower jaw which look like rodent incisors, giving them the common names “ratfish” or “rabbitfish.”

Great White Sharks (Carcharodon carcharias) are regularly hunted by orcas, and when one is confronted by an orca it will generally flee and not return to that area for up to a year.

Manta Rays (genus Mobula) are incredibly smart. They were the first “fish” in the world to pass the “mirror test” (ie show self-awareness by recognizing themselves in a mirror rather than seeing the reflected image as another manta ray). They also have highly-developed long-term memory, form friendships, and play with each other by blowing bubbles and breaching out of the water.

[bethanythebogwitch]

Wet Beast Wednesday: hagfish

After taking last week off for mental exhaustion I have returned! And what better way to mark my return than with a shitload (or perhaps a highway load) of slime? Today I'm returning to the agnathan trenches to dredge up one of two living groups of jawless fish. I covered lampreys before, so now it's hagfish time. These ooey gooey critters are both fascinating and kinda gross. Now get ready, because it's time for slime.

(Image: a hagfish in profile. It is a long, brown, eel-like animal with a fin encircling the tail and a small head with no visible eyes or mouth. End ID)

Hagfish, also known as slime eels, are approximately 76 members of the class Myxini. In addition to the living species, hagfish have been preserved in the fossil record, letting us track their evolution through history. Hagfish are one of two living groups of agnathans, commonly known as jawless fish, with the other being the lampreys. As the name suggests, jawless fish are vertebrates without hinged jaws. Way back when bones were the cool new thing in town, agnathans represented the entirety of the vertebrates and were extremely diverse, but the evolution of jawed fish resulted in them getting largely outcompeted, leading to all lineages but the hagfish and lampreys going extinct. Genetic studies indicate that hagfish and lampreys are more closely related to each other than either group is to any other vertebrate. Because they are the only jawless fish left, hagfish and lampreys are of interest to scientists studying the evolution of vertebrates.

(Image: a hagfish coiled up, under orange light. The head is visible, featuring small sensory barbels and a large hole that resembles a mouth but is actually the nostril. End ID)

Hagfish are eel-shaped animals that range in length from a few centimeters to over a meter in the largest species, Eptatretus goliath. They have no scales, flattened tails that bear the only fin, and simple, eyeless heads. The heads bear sensory barbels, a single nostril, and the mouth. The mouth has two pairs of rasping plates that normally sit within the mouth, but can be everted to face outwards. The plates can grab food and pull it into the mouth to be swallowed. Hagfish do not have true eyes, but they do have eyespots that can sense light and dark. Interestingly, their fossil ancestors did appear to have fully-developed eyes that reduced in complexity until the present state. Likewise, ancestral hagfish had a true vertebral column made of cartilage, but modern hagfish only have remnants of their ancestor's vertebrae. Hagfish skin is very loosely connected to the internal body, only attached along the spine and slime glands. This makes the skin very flexible and harder for predators to grab. A third of the blood is contained between the skin and body and is pumped around with the heart as well as a few additional pumps that act as auxiliary hearts. Hagfish have some of the lowest blood pressure of any vertebrate and the highest blood volume to body mass ration of any chordate. Hagfish are also the only vertebrates that do not osmoregulate, meaning they cannot regulate the amount of salt in their bodies. Changes in salinity, especially moving to a lower salinity environment, are very dangerous to hagfish. Hagfish skeletons barely qualify, consisting of only a skull, notochord, and fin rays, all made of cartilage. The gills are internal. Water enters through the mouth and is forced over 5-16 internal gill pouches, then ejected through pores in the side of the body.

(Image: a closeup of a hagfish head with the rasping plates everted. The plates are mounted on pink tissue around the pharynx. there are two plates on either side of the pharyx which look like rows of small, sharp teeth. End ID)

That's all well and good, but you're here because of the slime. The hagfish's main defense is to create lots and lots of slippery slime. The slime helps them slip away from predators. If a fish tries to eat a hagfish, the slime can clog up its gills, forcing the fish to either release the hagfish or suffocate. A common factoid is that a single hagfish can turn a 5-gallon bucket of water into slime in seconds. To produce the slime, the hagfish releases threads made of special proteins into the water from glands on its skin. These proteins react with seawater to create a matrix of trapped water held together by filaments similar to keratin. The slime matrix can expand 10,000 times its original size in 0.4 seconds of exposure to seawater. The slime is quite durable and resistant to breaking and dissolving in water. After sliming, hagfish have been seen wrapping their bodies into an overhand knot and running themselves through the loop to scrape the slime off of themselves. Its possible that the slime also impairs the hagfish's ability to use it's gills and it needs to do the know to get the slime off and breathe again.

(Image: a person reaching into a holding tank full of hagfish and pulling out an armload of thick, viscous, white slime. End ID)

(Video: a hagfish in the wild demonstrating its knotting behavior. This one is going in the opposite direction usually seen: tail-to-head instead of head-to-tail. End ID)

Hagfish are found in most of the oceans, with range varying based on species. They are benthic animals that rarely swim far above the seafloor. Some species dig burrows to shelter in while others will shelter under rocks and other structures to avoid predators. While lying on the sediment, some hagfish species will coil up while others will lie straight. Hagfish are carnivorous and feed with a combination of hunting and scavenging. A large portion of the hagfish diet consists of polychaete worms and other known prey species include small crustaceans and echinoderms. Some species have been known to hunt burrowing fish, possibly by clogging up the burrows with slime to suffocate the prey. If you've seen a documentary about deep-sea fish you probably know about hagfish scavenging. Using their large nostril and sensitive sense of smell, hagfish can sense carcasses from long distances and are often some of the first scavengers to arrive at a new body. They use their rasping plates to pull bits of meat off of the carcass. A similar behavior to the slime-cleaning knots is seen when scavenging, but in reverse, going from tail to head instead of the other way around. This grants the hagfish additional mechanical advantage, allowing it to rip off larger chunks of food. Hagfish will burrow into larger corpses, possibly to get access to a food source with less competition than the outside of the body. Hagfish act as part of the deep ocean's cleaning crew, consuming corpses before they can decay and release potentially harmful chemicals into the water or act as sources of disease. Unlike any other living chordate, the food a hagfish swallows is encased in a permeable membrane during digestion. Hagfish can also absorbed dissolved nutrients through their skin. Hagfish have a very slow metabolism and ones in captivity have been observed going for up to 7 months between meals.

(Image: several hagfish feeing on the body of a fish. The hagfish have their heads on the fish's body and one hagfish is entering the fish's mouth. End ID)

Hagfish reproduction is still something of an enigma as so many of them live in the deep sea, making it difficult to observe them reproducing. It has been observed that females seem to outnumber males, with the exact ration varying depending on species. In some species, the sex ratio is almost even, while in others, there are 7 females to each male. however, it should be noted that females mature sexually faster than males and it has been suggested that this is responsible for the apparent skewed ratio. Hagfish eggs have tufts at the end that cause them to get stuck to each other like velcro. It has been suggested that eggs are laid in clusters possibly in burrows, beneath rocks, or protected with slime. Some species seem to have a mating season and seasonally migrate. Hagfish have only a single ovary or testicle (the latter of which has been described as unusually small by scientists and bullies in the deep-sea locker room) and they have no specialized reproductive tract. Instead, gametes are released into the main body cavity and must find their way to the anus to leave the body. Hagfish embryology is poorly understood, though it has been reported from studies of Eptatretus stoutii (Pacific hagfish) that the eggs can take up to 11 months to hatch. Hagfish have no larval stage, unlike lampreys and bony fish.

(Image: a group of 9 hagfish eggs in a plastic tub. The eggs are ovoid and dark yellow, with tufts of fibers at each end. End ID)

The conservation status and needs of most hagfish species is hard to discern because of the depths they inhabit. Threats to them include bycatch, as hagfish are often caught during deep-sea dredges. It is alos possible the chemical pollutants may be passed to hagfish through scavenging. There is a commercial fishery for hagfish, which is largest off of the west coast of the Americas. Hagfish are eaten as a delicacy in Korea and less commonly eaten in Japan. Most of the hagfish fishery goes to Korean food markets. Hagfish skin is also values as a durable leather and often marketed as "eel leather" or "yuppie skin". Study of the slime and the highly durable threads that produce it indicates they could be used to create very strong materials, similarly to spider silk. Research is currently being undertaken to find uses for hagfish slime and threads.

Once again, these cards show up in my posts (Image the Weird n' Wild Creatures card for hagfish, featuring an exaggerated drawing on a hagfish. End ID)

[antediluvianechoes]

Fish, Konstantin Korobov

Dunkleosteus hunted in the shallows. There were fewer places for its prey to hide there. It was attentive to the tides, careful to avoid the rocks and swam only over the sands.

Snap!

Good-bye, Orodus.

Crunch!

Down goes an ammonite.

But, one morning, a tiny grey shark would not be caught. It dodged every lunge like a breeze does fingers. (Dunkleosteus did not know what a breeze was, but it would learn.)

Dunkleosteus grew as determined as a placoderm could, and—as much as a fish can decide anything—decided to catch this slippery prey above all costs. They chased through the shallows, charging and evading, reaching and retreating.

The tide began to go out. The shark winnowed over the rocks, its dorsal fin cutting the surface. Dunkleosteus surged at the shark, its back breaking the surface of the sea, its belly dragging over the stones. It nearly gutted itself on their sharp edges. The shark wormed away, but Dunkleosteus was stuck. The waters sloshed about its body. It struggled, heaved, wrenched its bulk against gravity and stone, but in vain.

The sea dragged the waters away, abandoning Dunkleosteus on the stones. Its gills pumped against the air; its eyes clouded in the wind; its fins curled over the corals. Then it was still, a victim of Devonian hubris.

[iguanodont]

Revisiting my designs for the “fish” of birgworld

Most notable change is moving their “gills” to the tail, where they are completely covered by skin/exoskeleton in derived species, and water is pumped over them either by motion of the tail or with a siphon on the belly. The siphon also aids in expelling mucous and waste material as a defensive measure. They propel themselves in an up and down motion inherited from the paddles of the ancestral form (top drawing), most of which have been modified into internal gills in modern species.

Also worth noting; the mouthparts are shown at least partially extended in all these sketches, but they would normally be folded flat against the head or tucked into the mouth when not in use.

[fishyfishyfishtimes]

Daily fish fact #737

Whitetip reef shark!

Unlike other requiem sharks, this species can pump water over its gills without needing to ram ventilate, which means it can stop moving and have a rest! These sharks are very slender and hunt at night by squeezing themselves into tight caves in their coral reef habitat.

[oc-ask-bloges]

I had.

Thoughts.

Pressure infection au. But it’s gas based.

I’m thinking something like the sirens from mlp (don’t ask why) not like something that affects you physically beyond like… eye color or smth.

More mental. Making who ever breathes it uncontrollably aggressive.

RAMBLE ALERT RAMBLE ALERT!‼️‼️‼️

So unless you had a gas mask on before the outbreak (for whatever reason, maybe like Allo from @creator-of-creativious) or use some type of filtered breathing like gills (external or filter gills like an Axolotl.) you would be effected.

Sebastian would be basically a “big bad” with his size and power. And the fact he has GUNS.

So saying that:

The ocs that would be aggressive:

Jixy (hiding away in some back room, probably heavily injured.)

Dani (small n feisty, more prone to bloodlust as well.)

Elena (justice god. Aka “oh no.”)

Lori (she has no lungs, is not effected, but it more aggressive for sake of survival.)

Ocs who are not aggressive:

Rose (@drowning-thistle. Has lungs, but the vines in her lungs pump a constant flow of fresh oxygen. Her head would be a big foggy though, causing some of her actions to be a bit brash. (Still a sweet heart, but still dangerous considering the VINES are effected. Her infection is sped up.).)

Navi (poor thing is completely harmless and helpless wether effected or not! She’s sticking to Rose’s side for the most part.)

Nebulon (no lungs. They’ve slinked back into the void mass controlled hallways. Doors have been blocked off.)

The Non Accountables.

Jix (hasn’t come up from the bottom of the ocean.)

Rain (trying their best to find an escape route from the outside. Horribly worried for Sebastian. (Gay.))

Safe houses.

Any space that’s blocked by water on all sides is safe. But the water isn’t. The gas can’t travel through the water, but it can get into it.

Most of Rose’s cafés. The over concentration of oxygen doesn’t allow for the gas to get in. It’s still dangerous to stay for a long period of time for normal breathers.

( @trepans-apprentice @faefrosting @birbisanon @corb1n +anyone you’d think would like this stupid idea.)

[tagzpite]

Obsessed with your fishsseus au, he's so hfsdufheuwhfuewhfw

I love him, I'll try to draw him at some point

Got any lore, fun facts or anything to tell us about the au?

I can sum up a few! One of Ody’s eyes is actually still able to see light and shadow, hence why I draw his left eye with a light pupil rather than full white like the other one.

Slight body horror warnings on some of these.

He has shark teeth.

He crunches of bones and clams to annoy Poseidon whenever he’s on his routine check up to torment.

The gills on his sides, under his arms over his ribs, are three on each because they are slashed in by Poseidon’s trident.

His tail has a colour shifting effect! Depending on how the light hits it that’s what colour you’ll see. I made attempts to make that obvious in my art.

His spines are venomous!

He sheds like a snake, which is great on his tail but on his human parts where scales are in patches and thin layers, it can be a pain.

Poseidon turned his shed into jewellery, since it’s a mix of fish and snake scale, it’s actually colourful.

He’s basically immortal in the terms of a life span.

His jaw can unhinge slightly wider than a normal human jaw.

Most of his innards are actually in his tail now, his chest is all lungs. Plus he’s got a second “back up heart” in his tail to help pump blood.

He has a third eyelid that prevents water from damaging his already sensitive eyes.

Since his eyes were pretty much destroyed, he can’t cry.

[maskedcop10]

AI created by dronifier-b45

NIck had been assigned as one of the new creations as an amphibian man for the Navy. He had been a diver in the Navy for some time and now, in a long process, he was transformed into an amphibian. He would spend the rest of his life underwater and when he had to come ashore, he had to wear special equipment and breathing systems. Nick was now equipped with gills and a special rubber body. The final stand was a final check in an airtight chamber. Nick stood in the center of the chamber, fully equipped with his heavy protective gear and special breathing systems. His special mask was attached to his suit and filled with a special gas, and the breathing tanks on his back were filled with a special liquid so he could breath. Underwater, he could remove the breathing systems and helmet and could breathe quietly, just like the other amphibious men made by the Navy. The sound of his heavy breathing filled the airtight space. Nick stood in the middle, with his muscular legs apart. The technician walked into the special room and checked the air and fluid supplies and connections. The tanks were completely filled until Nick could see fixed for a while. The technician's rubber glove moved over Nick's smooth body. He checked the special sheath the suite had. He felt at the sheath and with some effort the sheath came loose from the suit. Nick was fully aroused and pumped his cock. The sheath was very large and Nick had no trouble filling the sheath with his own monstrous meat. The technician could barely get his hand around it and Nick's breathing was now heavy as he fully erected himself. The technician checked the sheath for small leaks. At the technician's command, Nick let out a large amount of fluid from his monstrous cock, but it was all absorbed by the sheath and fed back into his life system. The technician turned around Nick and checked his ass. There was also an anal tube in his suit. He slowly moved two fingers into the anal tube. The tube was made of very heavy and thick rubber, for the rough and hard rearing these amphibian men do underwater. Nick was still rock hard and ready for the underwater action he was made for. The technician gave the final approval and left the airtight chamber. The heavy steel door was closed and water was slowly pumped into the chamber. Nick felt the water rush in. Soon he would remove the breathing systems and join his other amphibian friends deep underwater.

[beatinginavoid]

From the Deep

Every part of this room was custom built for one purpose. It was a purpose that many had believed would go unfulfilled. Yet here and now, the room was in use. The lights were dim, and reflected lights danced over the ceiling and some of the walls in mesmerising patterns, dancing and flickering endlessly.

The alluring light dance came from the ripples of the water that filled a massive tank. It took up the full length of one wall, a good thirty feet minimum. It was not quite fifteen feet tall, and contained no foliage or ornamentation, empty but for the water and one other thing.

A figure glided through the water. Sleek and swift, every motion it made caused more ripples on the surface.

The upper half of the figure resembled a young male human, while the lower half was that of a scaly tail with fins. A merman. A legend proven real.

He was a sight to behold.

He had been caught on the edges of the deep sea and seemed to live there. His body certainly suited that mostly unexplored area of the ocean, and what an intriguing body it was.

The merman’s entire body, from his short, wispy hair, to the very tips of his tail fin, was completely transparent. No muscles were visible, nor was there much of a skeletal figure to be seen beyond sharp teeth and a spine. Interestingly enough, no blood vessels could be seen, but every single internal organ, including the muscle that served as the heart, was completely on display.

Multiple cameras were focused on the tank, recording every movement, internal and external. This was groundbreaking new territory, history being made, and no one wanted to mess it up or miss a thing.

They only had one merman so they had to be incredibly careful.

There were thin, barely visible lines following the curves of what you assume are the ribs. The gills? The lungs resembled biology closer to a stingray or a shark, leaving more immediate space around the heart unlike a human, whose left lung hugged the muscle and partially hid it from sight. This was incredibly helpful for an unobstructed view of the epicentre of the cardiovascular system, especially for the excited medical staff that had access to this magnificent specimen.

Standing in front of the tank, the merman’s interest is caught right away and he lunges toward you. He smacks heavily into the glass, his shiny black eyes observing you unblinkingly, his head tilted in confusion as his hands lay flat against the tank wall. He floats to a stop upright, mimicking your posture.

The atria squeeze and his heart swells minutely before the ventricles twist a little and contract. The process repeats again and again, the pumping action fast and relentless. Throbthrobthrobthrobthrob. It’s so hard to look elsewhere because the motion is so hypnotic.

His heart appears to resemble a human’s so much, you can’t help but wonder if it sounds similar as well. A stethoscope was not an option, but there had to be a way.

Time slips by and you notice the rapid pace of his heart has slowed down significantly. Throb…throb…throb…throb…throb. You feel as if your own heart is trying to match it. Does his pulsing organ feel stronger than your own nestled in your chest?

Throb…throb…throb…throb-ob…throb…throb…

Was that a skip? Fascinating to witness!

Was it normal? Harmless? Indicative of a problem?

You scurry off to find help with your stethoscope problem, returning an hour later with a special microphone designed for underwater use. Such devices are used to record the sounds of dolphins and whales, and you hope it will be enough to pick up the merman’s heartbeat, especially if it ends up against his chest.

There’s a metal staircase at the far end of the tank and you ascend it. Leaning over and holding the microphone, the cord wrapped around a pole, above the water carefully, you lower it bit by bit. The microphone is attached to a box with a waveform metre and a speaker. It crackles and gurgles in a muted manner while it moves, the sound loudly reverberating around the mostly empty room.

You wedge the pole into place and resume your former spot before the tank. The microphone dangles in the water just above your eye line and your gaze quickly hones back in on the merman’s chest. The organic pump was still dutifully performing its sacred role, filling with blood and ejecting it to circulate around the rest of his body.

The mer himself gives you a cursory glance before hesitantly reaching out to the invader in his space. Fingers tipped with claws poke at it. Thuds ring out from the speaker and you smile.

He drifts closer to it, his face getting quite close. Fangs flash and the microphone screeches and groans as it is bitten. The mer lets it go quickly, jaw working open and closed a few times. It seems the taste, and maybe the texture, is not to his liking. A see-through hand grasps the microphone with surprising gentleness, creating a ruckus of awful, distorted noise.

Dexterous looking fingers inch their way up the microphone. A slender wrist follows, then a forearm and elbow. He continues to cautiously follow the cord higher and higher, and you bounce on your heels in eager anticipation as his chest finally draws level with the microphone.

Ba-thump…ba-thump…ba-thump…ba-thump…ba-thump…

There it is. What you’ve been waiting for.

The rhythm, the rate, the snap of valves, the distinct S1 and S2 sounds that make up the oh so familiar lub-dub. There is no way you would ever be able to distinguish this from a human’s regular heart sounds. This could be a major evolutionary find!

The merman freezes in place, his head tilting around. There were no visible ears but he was clearly listening to something. Could he hear the speaker projecting his sounds of life? After a few seconds he sucks in a sharp breath, holds it for a moment, and lets it out.

Ba-thump…ba-thump…ba-thump..ba-thump..ba-thumpba-thumpba-thumpbathumpbathumpbathumpbathumpbathumpba-thumpba-thumpba-thump..ba-thump..ba-thump..ba-thump…ba-thump…ba-thump…ba-thump…ba-thumpathump…ba-thumpathump…ba-thumpathump…ba-thump…ba-thump…ba-thumpathump…ba-thump…ba-thump…

His eyes are wide and he seemed as enthralled by the sound as you are. Several beats had visibly and audibly skipped and it had been an amazingly delightful experience for you. The acceleration and deceleration of that pulsing muscle was something that could keep your attention for hours.

Or until the call of nature became too much to ignore.

Your hand presses against your chest, your own heart meeting it with faint pushes as if determined to be a part of things.

Throbthrobthrobthrobthrobthrobthrob-

Ba-thump…ba-thump…ba-thump…ba-thump…ba-thump…

The fast pace of your heart feels weird as the merman’s restful beats fill the room. The two disparate rhythms seem to work together against all odds.

Human and mer stay in place, living in the moment.

-----

My first proper post on here and my first ever piece of cardiophile writing! 🫀🫀🫀 I hope you like it! I may make this mer an OC and play with him more...

pssst: will trade writing for art/anims

[meowmeowmeowmeow4x]

Dark Blue Moon and the Suffering Sun Chapter 16

MASTAPOST

tell me what u like about the chapter :D guess where the story's going, anything! gimme fuel qwq

Damian lay on his belly on Phantom’s chest as the boy floated just underneath the surface. It was night time, and the Atlantean town they’d sacked was far behind them now. Here they only had the stars to accompany them, wobbling and swaying over the distortion of the water.

They were so close… Damian pushed himself up with his arms. His head breached the surface, water washing over his face like a veil. His eyes widened as he took in the beauty of the night sky, much more comfortable without the blinding sunlight when he’d first tried this.

There was something comforting about the stars, something beautiful outside this world that would be there no matter what, even in his most miserable nights with the League. It was something he missed when he moved the Manor underneath Gotham’s smog-filled skies.

Damian pushed himself further, balancing himself on his tail and hip fins instead of his arms. The gentle sea breeze prickled at his wet scales, causing him to shiver. It brushed against his ear fins and gave a sense of immeasurable calm. Just him, Danny, the stars and the whistle in the wind.

And a feeling of suffocation.

Damian’s lungs demanded air. Or was it water? He inhaled deeply, taking in the smell of the sea from above it rather than underneath, but it didn’t help. He inhaled again, but the pressure remained.

What- What was this madness?! Sirens could breathe over water. This was indisputable. Danny had been able to breathe and talk over water the night Damian was transformed. Damian was able to breathe air and talk then. Damian sucked in more and more air, desperately trying to sate the need for oxygen. Why couldn’t he breathe?!

 Damian’s vision twisted. His head spun. His chest felt like knives being stabbed into it.

Hands grabbed him. Danny pulled him back under, where the water provided sweet relief. Damian clutched his chest, as if any moment now he would drown again.

“Are you ok Damian?” Danny’s hands hovered over him, like he was fragile china. Damian scowled.

“Why couldn’t I breathe? What has happened to me?” Damian asked, demanded, heavy with accusation.

“Dude, your lungs are water balloons right now. You gotta empty ‘em out before you can breathe air.” Danny said, like it was the most obvious thing in the world. Damian’s cheeks burned. He turned his back on Danny and crossed his arms.

“I was aware. I was merely testing you.”

Danny poked him in the sail, the sensitive touch causing Damian to hiss instinctively. “I mean if you’re the siren expert, then by all means!”

Damian did not dignify him with a response. Instead, he surfaced again, determined. Instead of inhaling in panic, trying to pump air into lungs at full capacity, Damian focused on exhaling, on pushing the water out.

His throat cramped with pain. The young siren gargled and gasped. His throat clamped and throbbed, like he was pushing a jagged boulder up. He barely managed to spit out a meagre drop of water before Danny dragged him under again.

The older boy pulled him to his chest, stroking his back as Damian coughed and hacked.

“Ok that was my bad, are you ok?” Danny said, ear fins drooping. Damian wheezed, his eyes closing as the pain abated.

“Do you go through this every time you surface?” Damian shuddered. What would happen to him once he got home? He wouldn’t be able to walk, and now couldn’t even breathe without immense pain.

“Hehe, no.” Danny deadpanned. “You’re supposed to use your gills.”

Danny tapped on his own gills. Instinctively, Damian moved his elbows to cover his. Lately he had been keeping sane by not thinking too much about the creepy feeling of having water flow through the slits in his chest, how exposed and vulnerable it made him feel. How it gave him a glaring weakness that could be easily exploited.

“Just open up your gills, and let the water drain out. It’s that simple.”

Damian sputtered. “What did you say?”

Danny shrugged, like he was explaining grade school mathematics to a two-year-old. “Like this.”

Danny’s gills flapped open. It was only from years of stoic training that Damian did not gag at the sight of Danny’s pale flesh revealed underneath his aquatic breathing apparatus. His eyes trailed to his own set of gills.

“Is there another way?” Damian was not avoiding this issue, nor was he ‘procrastinating’ as Richard would insipidly suggest. He was merely searching for a more optimal alternative.

“We’re sea creatures, Damian. I consider myself lucky for being able to not drown in air at all.”

Damian swallowed the lump in his throat. He was the son of Batman and Talia Al Ghul. He could face this. Being unable to breathe above water would make him a liability on this journey. He had to push through.

Damian prepared to resurface, gathering his nerves.

“Just relax. You can do it, Damian. It’ll be as easy as breathing.”

Encouraged by the prospect of not hearing any more puns, Damian pushed his upper half over the surface. Accordingly, Danny also pushed closer. This high over the water, Damian wobbled as his body adjusted to his weight in the air.

The pressure started to mount on his chest. Damian focused on the slits between his ribs, on the alien feeling of wind blowing into them and hitting exposed flesh. He squinted his eyes and tried to push the water out through his gills. He flexed and contracted his arms and stomach, searching for the unconscious switch in his brain that could activate the write muscles.

It was too much. He went under again.

“This is proving more difficult than I had anticipated.” Damian huffed, chest heaving from strain.

“I can tell.” At Damian’s glare, the older boy raised his hands in defense. “Hey, you looked legit constipated up there. I was starting to worry you’d actually make a mess of yourself. Now, like I said, all you need to do is-”

Damian hissed at the older boy’s mockery. “I can take care of myself. I need no advice to do something as simple as breathing. Thank you.”

Damian glared at the surface, the invisible barrier between this world and the old one, and redoubled his efforts. The pressure came back. Damian twisted his body and nerves, but he couldn’t get a single gasp of air in. He sank. He re-emerged, he suffocated again. Each time Damian pushed himself further, only to be met with the same difficulty. Each time left him sorer, more cramped.

Until after many an attempt, Damian slumped against Danny’s chest, scaled skin warm despite the cold, deep-sea looking appearance. His muscles turned to jelly, even as he feebly pushed against the older boy’s scales for another attempt.

The young siren felt soft hands wrap around his waist. Damian tried to push away, to wiggle out. Danny’s chest vibrated with a low him, and it was like his strings were cut, and Damian’s resistance ceased. All he could do was mutter weakly.

“What are you doing?”

Danny surfaced, arms keeping Damian under, until they began to pull him up too. Damian’s heart accelerated. He could not stop the frightened chitters forcing their way out. His fins went rigid. Was this it? Did Phantom finally lose his patience, and decide Damian was no longer worth the effort? This was bad. He needed to escape and he needed to escape yesterday.

But as Damian began to struggle, the rumbling vibrations from the elder’s chest intensified, and the small boy went limp again. His muscles, sore from exertion and rendered even weaker by the strange biological signal, refused to move. All he could do was tilt his head away, trying to delay the inevitable. Helplessly, he watched the surface creep closer and closer, until he went over.

Damian waited for his death. In his prayers, he apologised to Father, to Richard, even to Drake, for everything. In this moment, as tears pricked his eyes as he was helpless but to drown in fresh, oxygen-rich air, Damian resigned himself.

The pressure did not come.

His chest tingled. Pinpricks poked the skin and outer scales, and along the lining of his gills. Water ran down his chest and over his abdomen. Damian blinked, and looked down.

His gills were open, fully open, gaping wide and exposing his insides for the world to see, but they were open. And water flowed out of them, emptying his lungs. Damian gasped, and felt sweet relief as cold, burning, fresh air finally filtered into his body. His body wracked from the sweet release, chest struggling to accommodate the big greedy gulps he took.

“And now you shut them, keep the air going out the other way.”

Damian nodded glumly. That he could manage. A swift motion, and the flaps of scales and skin shut tightly, leaving only thin lines on his body to suggest that he ever had gills in the first place.

For a moment, he felt human. Even as he actively commanded his breaths, he felt more like a normal human again than he had in the last 48 hours.

“T-thank you.” Damian said, cursing the weakness in his voice. Not to mention how it sounded completely different now, travelling through water instead of air. It was unnerving, but he couldn’t place why. He felt too tired for more riddles about his body. “You have saved me a great inconvenience.”

Danny quietly chuckled. “It was literally what I told you. You need to loosen your muscles to get the water out. This whole time you’ve been all tight and wound up like a spring lock. Dude I think you even sleep all locked up too. That can’t be healthy.”

Sleep was when you were at your most vulnerable. Any threat could walk by and do with you whatever they pleased. In his life, there would be danger at every turn. It was a sentiment he’d expressed to the others in his family when they too voiced the same concerns.

He would never be safe in this life.

A finger poked his cheek. Damian snapped his teeth at the infantilizing gesture, only for it to retreat back just as quickly. He turned around and looked up, muscles no longer rendered limp by the subjugating vibrations.

Danny pointed to the sky, a soft smile on his face.

“It’s a good night to stargaze, isn’t it?” A comet whizzed by in the night, a streak of white trailing behind it, like an artist’s brush across a canvas. Now that he could breathe again, Damian felt an overwhelming sense of calm again, treading water and watching the stars shine.

[amiactuallydoingthisblog]

It’s a week before the finale and so I’m figuring out how the fish aquatic mammals (see my Telchin evolution post for details) can breathe air, freshwater, saltwater, and live on both land and the bottom of the ocean, which are questions I’ve had since we’ve met Ulysses. This post is going to be a bit more biological process/science communication heavy, but I’ve linked my sources where applicable.

First, lets talk about the gills. Gills are tissues that are filled with thin blood vessels called capillaries. As water is passed over the gills, oxygen diffuses from the oxygen-rich water into the oxygen-deficient blood. This works because particles/gasses/etc like to move down their concentration gradient, from areas of high concentration to areas of low concentration.

To have a consistent supply of oxygen, water needs to be constantly flowing over the gills. This is easy to do while the Telchin are swimming, but when they’re not, my thought is that the ear fins flap to push water down past the gills.

In order to live on the bottom of the ocean, Telchin would have to deal with the pressure difference. Marine mammals in real life can dive down to 2,000 feet, and they are able to mitigate the change in pressure using a number of adaptations. The main one which I think the Telchins use is the collapsing/contracting of the lungs and other airways to prevent them from imploding under the pressure. They also would have thicker/more insulated skin to help with the cold that comes with the deep ocean.

The salinity (amount of salt) of the environment is important to any organism, but especially to aquatic animals. Salmon and American eels, however, are two species that travel from saltwater to freshwater over the course of their life cycles. Salmon (and by extension, the Telchin) can do this because of a number of adaptations, most importantly a molecular pump in the cell walls of the gills that pump salt out of the blood when they’re in saltwater and into the blood when they’re in freshwater.

As far as I know, only lungfish breath both air and water. They are almost the reverse of Telchin, having started out with gills and then evolving a primitive sort of lung. Telchin have both lungs and gills, so they can mechanically breath both air and water, but my question is how they change from breathing water to breathing air. My hypothesis is that when the O2 levels in their blood are too low, they switch methods of breathing.

Your body already senses the amount of oxygen (I tried to find a suitable popular source for this and failed, so this is a scholarly article, just so y’all know) in the blood, and responds when O2 levels are low. When a Telchins oxygen levels are low, their body will either lessen the blood flow to the gills and open up the lungs (using the same system that prevents the lungs from being crushed by the pressure) or vice versa, increasing blood flow to the gills and closing the lungs.

In summary: fish can do cool things, and therefore so can the Telchin.

[shark-a-day]

Todays shark is...

A Nurse Shark!

Fun fact! Unlike most other species of sharks, Nurse sharks dont need to keep moving to move water over their gills! They pump water over their gills by continuously opening and closing their mouth!

[olivyh]

Hihi!! I absolutely love your writing :DD

Can I request an Azul x Gn!Reader in which the Reader asks Azul a bunch of ocean questions and Azul answers them in excruciating detail? Fluff please!! The questions are completely up to you :D

Please take as much time as you need on this!! Make sure to take breaks and drink water :))

Hi!! Thank you so so much <<333 sorry for the delayed response, but this was so much fun to write! I'm not the best at ocean facts, so I hope this will suffice!!! I also hoped going to more lore-based questions was alright with you!

"So... how exactly do you breathe underwater?" Azul paused and looked up from his paperwork, unable to stifle the smile that slowly crept onto his previously pursed lips. It was a quiet day in the Mostro Lounge- Floyd was actually working for once, and there weren't any rowdy customers. He'd only gotten two contract deals, much to his dismay, but he was glad that he had more free time to spend with his lover. The prefect sits in one of the wooden chairs pulled up to his desk, a plate of shrimp chips and seaweed wafers between them and munches happily, their crunching breaking the silence that was otherwise occupied by the scratching of his pen.

Lately, the two had not had much time to spend together- what with their constant running around (Azul swore that he was going to pluck all the feathers from that crow if he overwhelmed them one more time) and his busy schedule. He felt a stab of regret after watching them fall asleep in his office one night, waiting for him to finish his endless mountains of work simply so they could have dinner together. Azul had never felt his heart constrict so painfully that it brought tears to his eyes when he saw that they made him dinner in a small box, the food having gone cold hours prior. He'd sat beside them on the firm leather couch then, slowly tracing over their features with his ungloved hand and biting back the tears that broke free from his sky-blue eyes and fell freely onto the back of his other hand, clenched painfully in his lap.

"We have gills, naturally," He pauses and lifts a finger, dragging it along the large marks that lined the sides of his neck- now made visible from his unbuttoned collar. "They never fully went away in our human forms. As you know we have gills on our ribs as well. We actually have to breathe through our mouths, which then moves through our bodies and into the gill's capillaries-" He pauses, looking over to meet the prefect's eyes. He flushes a bit under their unwavering attention, but he clears his throat and continues despite the pounding in his chest. "From there, the water runs over the gills and the oxygen is picked up by these blood vessels before being expelled from the gills."

"So the water goes out and not in?"

"Correct," He smiles, raising his hand and wiping away some crumbs that made their way onto their cheek. Azul huffs playfully, chuckling under his breath. "Really, such a messy eater~". The prefect sticks out their tongue playfully before moving onto another chip, popping it into their mouth and chewing carefully while staring at the ceiling, seemingly deep in thought.

"What if you accidentally breathe something in? Can you choke?"

Azul sighs and sits back in his chair, placing his pen down and crossing his arms. He doesn't miss how they seem to grin at him and his now relaxed posture- meaning that they would be talking like this uninterrupted for a good amount of time.

"We can't choke, my Dear," He takes a breath before pointing to the marks on his neck once more. "The oxygen goes in here and then is pumped into our lungs- unlike humans, our lungs aren't connected to any sort of windpipe and is instead filtered through our blood vessels-" He moves his hand down to his ribs, drawing invisible lines along the sides. "And food can't necessarily get stuck in here either. There are no direct passageways- they're simply slits in our skin to allow for breathing."

"So," They eat another chip, offering him another one. He gladly accepts it, leaning over and allowing them to feed it to him before leaning back in his chair. "Your lungs are free floating?"

"Not exactly. It's more like... there's nothing connecting them to our throats, if that makes sense." They hum in understanding, standing quickly. The mer jumps in his seat from the sudden action, feeling his face flush when they decide to abandon their seat and replace it with his lap.

Azul swears that he saw the heavens themselves beckoning for him when he feels their fingers lightly trace over the lines on the sides of his neck before trailing down to his ribs.

"So here... and here..."

Azul, struggling to catch his breath, nods. They had been dating for quite some time, and he should very well be used to their antics by now, but he could never get over the sudden spurts of physical affection they'd give him. The small and intimate gestures made his heart race and his head spin as he could swear that his legs were turning back into tentacles as the floor seemed to warp beneath his leather shoes. Their hand slowly traces back up to his neck, giving the marks one more affectionate rub before cupping his cheek. Their soft thumb rubs the skin just below his glasses, their nail clicking against the glass for a moment as he sighs happily and leans into their touch, allowing his own hand to run gently up their forearm. He relishes in the way their hand trembles for a moment and the goosebumps that begin to litter the exposed skin of their arm, glad to know that they weren't the only one to have this effect on him.

He cups their hand in his own, pressing his cheek deeper into their warm palm as he slips his eyes closed and sighs happily, turning his head ever so slightly to press a small kiss on the underside of their wrist, allowing his lips to linger there for a moment until he could hear the way their breath hitched and their thumb's movement on his cheek stuttered.

Azul opens his eyes in time to notice their face approaching his, and he beams at the giddiness and excitement that bubbles in his chest as they pepper his face in kisses playfully, spending more time to give extra love to the mole that sat below his lip. He chuckles and does the same to their face, using his free arm to hold them close to his chest as they squirm and giggle at his actions.

The mer parts for a moment, smiling softly as his eyes trace over their flushed face, still painted with a warm smile as their eyes crinkle from the effort, turning them into the most gorgeous half-crescent shapes he swore he'd ever seen. He looked over each and every one of their features, trying in vain to immortalize this moment and live in it forever; to take hold of this comfort and adoration that consumed his spacious office and put it in a bottle for his eyes alone.

"Any other questions for me, my Dear?" They shift in his lap, now fully facing him and resting their head against his shoulder, yawning. "I'm all yours."

"I know you are," He chuckles at their response and presses a kiss to their forehead, running his hand along their hairline until he notices that their shoulders begin to rise and fall evenly as their soft snores fill his ears. Slowly, he releases their waist and reaches behind him to pull his jacket off the back of his chair. With a little difficulty, he manages to wrap it around his still-sleeping lover as he relaxes beneath them. He sighs and takes his glasses off, tossing them haphazardly onto the hardwood of his desk, and rests his head against his lover's own, deciding that he was due for an afternoon nap as well.

[greengold-c]

Merfolk Tavern Seating

“Can you stop swimming in circles around me? Makes me feel like prey.”

“The circling? And not the spear?” Semeru smirked, flicking his wrist to make his spear spin. “I know you won't hurt me, the circling...I dunno. Feels intimidating in a primal way.”

“I can't stop. Drawback of being a Great White, I'll suffocate if I stop moving.”

“Really? But I've seen you sit at the tavern.”

“There are pipes installed in seaweed beds and near pretty much any public seating that pump oxygenated water. That way Merfolk who can't use buccal pumping can rest without dying. None of that here though,” he said, motioning at the open ocean around them.

🦈 Shark fact: Fish breathe via buccal pumping and/or ram ventilation. In buccal pumping, the fish uses its buccal muscles to pump water into its mouth and over its gills. In ram ventilation, the fish swims forward in order to pass oxygenated water over its gills. Some sharks, including great whites, are obligate ram ventilators. These fish are unable to use buccal pumping and must continuously swim to pass water over their gills. They would die if they stopped moving. How do we reconcile the existence of obligate ram ventilators like Semeru with furniture that requires one be stationary for use, like seaweed beds and tavern seating? Nature has the answer! Sharks known to be obligate ram ventilators are found alive and motionless in Cave of the Sleeping Sharks. There is an underground (freshwater) spring that feeds into the cave, creating a current of oxygenated water that allows them to breathe without moving. So- seaweed beds and tavern seats? They're outfitted with pumps, so all can relax for a while. I think this aspect of great white anatomy has decent potential for content. Sleeping for the first time as an adult on land? Terrifying. Telling an obligate ram ventilator Merfolk to stop swimming? Highly offensive.

[fishenjoyer1]

Fish of the Day

Today's fish of the day is the shovelnose guitarfish!

The shovelnose guitarfish, scientific name Pseudobatos productus, is a common ray. Named for the guitar-like shape of their body and the particularly pointed nose, this fish can be found along the Pacific coast. From San Francisco, to the gulf of California, and possibly as low as Mazatlan, Mexico. These fish live in subtropical-temperate regions spending their time along the sea bed and away from large animals. TFound around rocky reefs and soft or sandy bottomed areas, the depth range is anywhere from 1-91 meters, but they prefer to live 1-13meters.

The diet of the shovelnose guitarfish is dependent on their benthic lifestyle, as animals living exclusively on the seabed. They prey on crabs, worms, clams, and small fishes also living along the seafloor. During the day this fish lies in wait until prey comes close enough to it, at which point it will lunge out swallowing prey whole. But, during the night the shovelnose guitarfish actively hunts the sea floor, looking for unsuspecting animals. They tend to hide during the day as they are regularly predated on by seals, sharks, whales and large fish.

Some of the more interesting biological realities of the shovelnose guitarfish is in the gills and eyes. The gills are particularly delicate, and as such this guitarfish pumps water in through spiracle holes on the top of the head, running water over the gills. Filtering through the openings and out. This allows them easy breathing despite their stationary ways hiding on the sand. On the other hand, the eyes of the shovelnose are more extensive than most other cartilaginous fishes, as they have many larger than average projections connected into the brain. This gives them a better ability to see than most rays and sharks.

Shovelnose guitarfish give birth to live young, as embryos will feed on the yolk of the egg within the womb. Breeding takes place in shallow bays and estuaries, and after this gestation will take anywhere between 10-12 months. Then, they'll give birth to anywhere between 6-28 pups, and are born during the pupping season of June-October, in the same shallow water breeding takes place in. At their full adult size, they'll get as large as 1.7meters in length, just around the time they reach sexual maturity. These fish will sexually mature by 7-8 years old, and only live around 11-16 years, living through anywhere from 3-9 breeding seasons.

That is the shovelnose guitarfish, have a wonderful day!