Tumgik
#old man fish
bethanythebogwitch · 7 months
Text
I recently found out a show I liked is 10 years old now so to not be the oldest thing on this blog I'm talking coelacanths for Wet Beast Wednesday. Coelacanths are rare fish famed for being living fossils. While that term is highly misleading, it is true that coelacanths are among the only remaining lobe-fined fish and were thought to have gone extinct millions of years ago before being rediscovered in modern times.
Tumblr media
(image id: a wild coelacanth. It is a large, mostly grey fish with splotches of yellowish scales. Its fins are attached to fleshy lobes. It is seen from the side, facing the top right corner of the picture)
Coelacanth fossils had been known since the 1800s and they were believed to have gone extinct in the late Cretaceous period. That was until December 1938, when a museum curator named Marjorie Courtenay-Latimer was informed of an unusual specimen that had been pulled in by local fishermen. After being unable to identify the fish, she contacted a friend, ichthyologist J. L. B. Smith, who told her to preserve the specimen until he could examine it. Upon examining it early next year, he realized it was indeed a coelacanth, confirming that they had survived, undetected, for 66 million years. Note that fishermen living in coelacanth territory were already aware of the fish before they were formally described by science. Coelacanths are among the most famous examples of a lazarus taxon. This term, in the context of ecology and conservation, means a species or population that is believed to have gone extinct but is later discovered to still be alive. While coelacanths are among the oldest living lazarus taxa, they aren't the oldest. They are beaten out by a genus of fly (100 million years old) and a type of mollusk (over 300 million years old).
Tumblr media
(image: a coelacanth fossil. It is a dark brown imprint of a coelacanth on white rock. Its skeleton is visible in the imprint)
Coelacanths are one of only two surviving groups of lobe-finned fish along with the lungfishes. Lobe-finned fish are bony fish notable for their fins being attached to muscular lobes. By contrast, ray-finned fish (AKA pretty much every fish you've ever heard of that isn't a shark) have their fins attached directly to the body. That may not sound like a big difference, but it actually is. The lobes of lobe-finned fish eventually evolved into the first vertebrate limbs. That makes lobe-finned fish the ancestors of all reptiles, amphibians, and mammals, including you. In fact, you are more closely related to a coelacanth than a coelacanth is to a tuna. Coelacanths were thought to be the closest living link to tetrapods, but genetic testing has shown that lungfish are actually closer to the ancestor of tetrapods.
Tumblr media
(image id: a scientific diagram depicting the taxonomic relationships of early lobe-finned fish showing their evolution to proto-tetrapods like Tiktaalik and Ichthyostega, to true tetrapods. Source)
There are two known living coelacanth species: the west Indian ocean coelacanth (Latimeria chalumnae) and the Indonesian coelacanth (L. menadoensis). Both are very large fish, capable of exceeding 2 m (6.6 ft) in length and 90 kg (200 lbs). Their wikipedia page describes them as "plump", which seems a little judgmental to me. Their tails are unique, consisting of two lobes above and below the end of the tail, which has its own fin. Their scales are very hard and thick, acting like armor. The mouth is small, but a hinge in its skull, not found in any other animal, allows the mouth to open extremely wide for its size. In addition, they lack a maxilla (upper jawbone), instead using specialized tissue in its place. They lack backbones, instead having an oil-filled notochord that serve the same function. The presence of a notochord is the key characteristic of being a chordate, but most vertebrates only have one in embryo, after which it is replaced by a backbone. Instead of a swim bladder, coelacanths have a vestigial lung filled with fatty tissue that serves the same purpose. In addition to the lung, another fatty organ also helps control buoyancy. The fatty organ is large enough that it forced the kidneys to move backwards and fuse into one organ. Coelacanths have tiny brains. Only about 15% of the skull cavity is filled by the brain, the rest is filled with fat.
Tumblr media
(image id: a coalacanth. It is similar to the one on the above image, but this one is blue in color and the head is seen more clearly, showing an open mouth and large eye)
One of the reasons it took so long for coelacanths to be rediscovered is their habitat. They prefer to live in deeper waters in the twilight zone, between 150 and 250 meters deep. They are also nocturnal and spend the day either in underwater caves or swimming down into deeper water. They typically stay in deeper water or caves during the day as colder water keeps their metabolism low and conserves energy. While they do not appear to be social animals, coelacanths are tolerant of each other's presence and the caves they stay in may be packed to the brim during the day. Coelacanths are all about conserving energy even when looking for food. They are drift feeders, moving slowly with the currents and eating whatever they come across. Their diet primarily consists of fish and squid. Not much is known about how they catch their prey, but they are capable of rapid bursts of speed that may be used to catch prey and is definitely used to escape predators. They are believed to be capable of electroreception, which is likely used to locate prey and avoid obstacles. Coelacanths swim differently than other fish. They use their lobe fins like limbs to stabilize their movements as they drift. This means that while coelacanths are slow, they are very maneuverable. Some have even been seen swimming upside-down or with their heads pointed down.
Tumblr media
(image: an underwater cave wilt multiple coelacanths residing in it. 5 are clearly visible, with the fins of others showing from offscreen)
Coelacanths are a vary race example of bony fish that give live birth. They are ovoviviparous, meaning the egg is retained and hatches inside the mother. Gestation can take between 2 and 5 years (estimates differ) and multiple offspring are born at a time. It is possible that females may only mate with a single male at a time, though this is not confirmed. Coelacanths can live over 100 years and do not reach full maturity until age 55. This very slow reproduction and maturation rate likely contributes to the rarity of the fish.
Tumblr media
(image: a juvenile coelacanth. Its body shape is the same as those of adults, but with proportionately larger fins. There are green laser beams shining on it. These are used by submersibles to calculate the size of animals and objects)
Coelacanths are often described as living fossils. This term refers to species that are still similar to their ancient ancestors. The term is losing favor amongst biologists due to how misleading it can be. The term os often understood to mean that modern species are exactly the same as ancient ones. This is not the case. Living coelacanth are now known to be different than those who existed during the Cretaceous, let alone the older fossil species. Living fossils often live in very stable environments that result in low selective pressure, but they are still evolving, just slower.
Tumblr media
(image: a coelacanth swimming next to a SCUBA diver)
Because of the rarity of coelacanths, it's hard to figure out what conservation needs they have. The IUCN currently classifies the west Indian ocean coelacanth as critically endangered (with an estimated population of less than 500) and the Indonesian coelacanth as vulnerable. Their main threat is bycatch, when they are caught in nets intended for other species. They aren't fished commercially as their meat is very unappetizing, but getting caught in nets is still very dangerous and their slow reproduction and maturation means that it is long and difficult to replace population losses. There is an international organization, the Coelacanth Conservation Council, dedicated to coelacanth conservation and preservation.
Tumblr media
(image: a coelacanth facing the camera. The shape of its mouth makes it look as though it is smiling)
1K notes · View notes
lazer-meme · 7 months
Text
love love love steddie + supportive wanye
thinking about wayne and eddie going on an annual fishing trip (like thee Munson Men Annual Fishing Trip™️) just like a little weekend away. and the first one is coming up after eddie and steve starts dating. over breakfast eddie jokingly complains about having to go and tries to get out of it. but wayne is used to his dramatics so he just gives hmms when appropriate because eddie’s whole spiel never got him out of it before and he tells eddie that.
steve watches the whole exchange with amusement when wayne asks if he’s looking forward to it. and he’s like ??? because he assumed it was just a wayne and eddie thing. and wayne is like i just told eddie all munsons must go can’t get out of it kid.
steve gets flustered and is internally is like oh??? all munsons,,,
or like after the trip a neighbor asks wayne if they caught anything and he pulls out his wallet to show a picture they took on the trip. wayne passes it with ‘here’s a picture of my boys’ and to steve’s surprise it’s a picture of both him and eddie with their biggest catch.
and just idk wayne casually accepting steve into their family and throwing steve off guard with it.
3K notes · View notes
avephelis · 4 months
Text
top ten riptide bits that make me pause the episode and physically recoil and walk away for a day and resort to homophobia and
778 notes · View notes
gabelew · 6 months
Text
Tumblr media
captain bazz's adventures in demoralizing the youth
featuring teen sidon being just too impressed by his first fancy drink
609 notes · View notes
timtamsart · 9 months
Text
Tumblr media
Your honor, the are in love
831 notes · View notes
unsanctitude · 5 months
Text
Tumblr media Tumblr media
cracks open my coffin lid to show my newest disgusting old person furry
333 notes · View notes
teisubrainrot · 1 month
Text
Tumblr media
old(est so far) man yaoi
Tumblr media
ye
136 notes · View notes
oldschoolfrp · 4 months
Text
Tumblr media
Glitchegumee Swamp is a good place to hide out, except for the bird-sized mosquitoes, and the hungry crocs, and the singing myconids that always scare away the fish. (Terry Dykstra cover art, Dungeon 41, May/June 1993, featuring the AD&D adventure "Old Man Katan and the Incredible, Edible, Dancing Mushroom Band" by Ted James Thomas Zuvich)
211 notes · View notes
spotsupstuff · 1 year
Text
Tumblr media Tumblr media Tumblr media Tumblr media Tumblr media Tumblr media
gettin' back into the swing of makin' ocs this year it seems 🤨
bonus, Seaf and his hooligans:
Tumblr media
783 notes · View notes
gaywarcriminals · 1 month
Text
Once finally left alone, Shen Qingqiu resisted the urge to snoop for all of 20 minutes. Look, if he was going to be stuck living as this man, he was within his rights to go through the original goods stuff! It was research, really— he was just doing his best to obey the systems draconian demands of staying in character! It was a perfectly sound course of action— Shen Qingqiu just wished he hadn’t started with the bedroom. 
There, in the second drawer Shen Qingqiu gleefully yanked open, was a neatly lined up row of items sealing Shen Qingqiu’s death sentence. Shen Qingqiu wanted to cry as he started at the vials of oils and jar of unguent, the coil of bright red ropes, and most damningly of all, a hyperrealistic dildo carved of black jade, big enough to rival the heavenly pillar. Shen Qingqiu knew the original goods was lascivious, but immortal biding cables? What poor shimei was he forcing??? And that thing: surely it couldn’t fit comfortably inside any woman, at least not without the protagonist’s skills to ease the way! Shen Qingqiu picked up the weapon— there was no better name for it— and wondered if destroying it would spare him any torture. Surely at least a fingernail or two!
“Qingqiu, I forgot to ask, did—“
Shen Qingqiu made a very dignified sound of surprise as Yue Qingyuan entered the room behind him. Yue Qingyuan stopped in his tracks, looking between Shen Qingqiu and the jade monstrosity. Shen Qingqiu opened his mouth to make an excuse, but what could he say? This scene was inexcusable. Dying of mortification was certainly one way of avoiding being human sticked! 
“Qingqiu, you’ve barely gotten out of bed, you can’t possibly be ready for dual cultivation yet. Look how red you are, you must still be feverish.” Shen Qingqiu stared agape as Yue Qingyuan moved too close for propriety and pressed his hand to Shen Qingqiu’s forehead. He hummed consideringly. “I’ll go fetch Mu-shidi.”
“No.” Shen Qingqiu squeaked— the last thing he needed was another witness!
Yue Qingyuan sighed indulgently. “Alright, If Qingqiu is truly in need, this Qi-ge will use his mouth.” 
For the second time that day, Shen Qingqiu fainted.
88 notes · View notes
dragonbma · 2 months
Text
Even gods get lonely sometimes.
Tumblr media
77 notes · View notes
lucky-draws · 4 months
Text
Tumblr media
martha jones most beautiful awesome woman on my tv 2006-2007 etc
116 notes · View notes
mossiparks · 2 months
Text
Tumblr media
finally got around to finishing this ⭐️
tank ft the grandbabies
89 notes · View notes
bethanythebogwitch · 11 months
Text
We're going to take it slow this Wet Beast Wednesday and talk about Somniosus microcephalus, the Greenland shark. Its one of the sleeper sharks, a family named for their very slow movement and generally low-activity lifestyles. Greenland sharks follow the rule that slow and steady wins the race. With a top speed of 2.6 km/h (1.6 mph), the Greenland shark has the slowest speed of its size of all fish. They also have a slow metabolism which correlates with a very long lifespan. The lifespan of these sharks isn't known for sure, but given that they grow at a rate of about 1 cm per year and can reach around 6 meters in length, they can live a pretty long time. Normal methods of aging sharks don't work on the GS. Sharks are usually aged by counting growth rings on fin rays or vertebrae, but Greenland sharks don't have fin spines and their vertebrae are too sift to form growth rings. In 2016, a paper titled "Eye Lens Radiocarbon Reveals Centuries of Longevity in the Greenland Shark (Somniosus microcephalus)" by Nielsen et al. was published that described a new aging method in which crystals in the eye lens could be radiocarbon dated to provide and age estimate. The oldest shark they tested was aged at 392 ± 120 years old. If the lifespan falls on the upper end of that range, it could give the GS a maximum age of 500 to 600 years old. The same paper also estimated that they don't reach sexual maturity until around 150 years old. The GS is officially listed as the longest-lived of all vertebrates.
Tumblr media
It looks like somebody tried to draw a shark from memory (image: a Greenland shark swimming under ice)
The extreme age and slow lifestyle of the sharks is linked to their habitat. Despite the name, they are not only found around Greenland. In fact, they live in very cold waters (0.6 - 12 degrees C or 31 - 54 degrees F) in the north Atlantic and Arctic Oceans. They are the only shark species to live in arctic waters all year round. It is likely that they have a much larger habitat range than we know as they spend most of their time in very deep water. One specimen was found as far south as the Caribbean. It's possible that the north Atlantic and Arctic Oceans are the only places in their range that are cold enough for them to tolerate surface conditions and in the rest of their range they stay in deep, cold water. Being an ectothermic (cold-blooded) animal living in very cold conditions requires a very slow metabolism and slow metabolisms are linked to longer lifespans. A slow metabolism also requires less energy, which is very advantageous for seep-sea animals, who may be forced to go for months or longer between meals. The size of the shark may also be linked to its habitat. At up to 7 meters (23 feet) long and 1,400 kg (3090 lbs), the GS is one of the largest fish in the world. This size could be an example of deep-sea gigantism, a phenomenon in which deep-sea animals grow much larger than their shallow-water relatives. There are many proposed explanations for deep sea gigantism, including cold temperatures inducing growth (Bergmann's rule), improved foraging ability, defense against predators, and greater dissolved oxygen availability in colder and deeper waters. Because of their abyssal habitats, Greenland sharks are rarely observed in the wild and we know little about their natural behavior.
Tumblr media
(Image: a scuba diver swimming next to a Greenland shark)
What does a large carnivore living in food-scarce deep water eat? Just about everything. Greenland sharks are generalists who will eat almost any meat. They are both scavengers and active predators, with a diet consisting primarily of squid as juveniles and fish as adults. Most of what we know about their diet comes from the stomach contents of dead specimens as they have very rarely been observed feeding in the wild. Seals also make up a large portion of their diet. As it's very unlikely that such a slow shark could chase down and catch a seal for lunch, the shark likely targets sleeping seals. Greenland sharks are scavengers who likely get a lot of nutrition from carrion. They have very sensitive noses that they use to track down rotting meat. Stomach contents have revealed meat from various animals, including polar bears, moose, and reindeer. They are known to follow fishing boats to snatch up any scraps. Greenland sharks are apex predators who play an important role in the Arctic ecosystem.
Tumblr media
(Image: a Greenland shark captured by a fishing boat)
As mentioned above, Greenland sharks are estimated to reach sexual maturity at around 150 years old. They are ovoviviparous, meaning that the eggs hatch while still in the mother, who then gives live birth. A typical litter has around 10 pups (likely the maximum given the metabolic requirements of reproduction) that are about 38-42 cm (15-16.5 in) long. Due to their lifespan, it is estimated that a single female could produce between 200 and 700 pups during her life. Unconfirmed reports have been made of them hybridizing with other sleeper sharks.
Tumblr media
(Image: a 100-year old juvenile shark that washed up on a beach in England)
Greenland sharks are often found infested by the parasitic copepod Ommatokoita elongata. This parasite attaches itself to the cornea of the eye and infests both the Greenland shark and the Pacific sleeper shark and dangles out of the eye like a thread. The presence of the copepod damages the eye, leaving the shark almost if not entirely blind. This doesn't actually seem to hurt the shark that much as they rely mostly on smell and hearing. One hypothesis stated that the copepod may bioluminesce to attract prey to the shark, but this remains unconfirmed.
Tumblr media
(Image: a close-up of a Greenland shark eye infested with a copepod)
Now to address the elephant seal in the room: Greenland sharks stink. All elasmobranchs have concentrations of the compounds urea and trimethylamine N-oxide (TMAO) in their bodies, but the GS has a higher concentration of these compounds than other species. The compounds are waste products retained by elasmobranchs to aid in buoyancy and the GS has more because they also help resist the pressure of the deep ocean. The concentration of urea is high enough that you can smell it if the shark is near you. Urea is a key component of urine. Greenland sharks smell like piss. The high levels of TMAO makes Greenland shark meat toxic to humans. Despite this, people still eat the meat, but it must be treated first. This can be done by boiling the meat multiple times or by fermenting it. A national dish of Iceland, kæstur hákarl, consists of Greenland shark meat that has been buried underground in gravelly sand and pressed with stones, then left to ferment for 6-12 weeks. It is then dug up and cut into strips, which are hung up and left to dry for several months. Apparently first time eaters are known to gag because of how much ammonia is in the meat. I don't think I'll try any.
Tumblr media
(Image: hákarl hung up to dry)
Because of their deep-sea habitat, Greenland sharks have relatively few interactions with humans. In the past, They were hunted for their liver oil, but in modern days, there is no fishery for them. Greenland sharks are classified as vulnerable by the IUCN. Their primary threat is bycatch and they are likely being affected by ocean warming and loss of sea ice in the Arctic. Because of their slow maturity and low fecundity, Greenland sharks are particularly vulnerable to population loss. There are no recorded attacks on humans. The species features in the legends of the Inuit. The legendary first Greenland shark was named Skalugsuak and one story says it was born after a woman washed her hair with urine (a lice remedy) and dried it with a cloth. The cloth then blew into the ocean and turned into Skalugsuak, who still smells like urine. Another legend says that the shark lives in the urine pot of Sedna, the sea goddess, explaining its smell.
Tumblr media
(image: scientists tagging and releasing a small Greenland shark)
322 notes · View notes
cambriancutie · 4 months
Text
Tumblr media
me if i lived in fish world
55 notes · View notes
cthulhusstepmom · 1 year
Text
Ghost is observant. He's always been, even before it was his job. It kept him safe, safe from his father's worst moods, safe from bullies at school, safe from the inevitable deterioration of all of his relationships.
So when Soap starts acting suspicious he feels his heart start to sink. He's a big enough person to admit that he's been selfish with Soap, allowed himself to indulge in genuine companionship; allowed something dangerous to develop. But what choice does he have? The thought of leaving now and denying himself the simple warmth of John MacTavish is almost a physical pain. So it should be a relief when Johnny starts to pull away, it saves Ghost from being the one to do it. But for once in his long trail of broken hearts and slowly withering relationships, Ghost doesn't want it to end.
So he clings on. He seeks him out more often, snaps and snarls at the thought of Soap going out of his sight. He lays there listening as Soap wakes with a haunted scream, internally wrestling with himself until he gathers the courage to cross the hall and knock, his cheeks heating when Soap answers the door in just his boxers. He kicks himself when Soap redirects and prepares to bow out and take the dismissal respectfully when Johnny offers to come and sit with him and his traitorous heart soars in his chest. Soap is giving him this and he'll take it with gratitude. They sit together in the rec room for hours, watching the fish sleep peacefully until Soap has drifted off and his tea is in danger of spilling in his limp hand. He briefly considers taking Johnny back to his room but he rationalizes that there is a reason the Soap didn't want him in there and it really isn't his business. So he sits there and he observes. Simply watching the slight rise and fall of Johnny's chest as he sleeps on the tattered couch. Indulging in the domesticity of it all.
When a knock jars him awake in the middle of the night he's unsure what he expects but Soap delirious and bleeding was certainly not on the top of that list. A small lick of pride flares inside of him that Soap would come to him before medical, which brings with it quiet concerns and many questions. Still he brings Johnny inside and sits him gently on his bed, stepping into his bathroom to quickly grab his personal first aid kit.
Soap is saying something when he gets back, so deep in his accent that it doesn't even register as words. Kneeling on the floor in front of him, Ghost reverently takes his arm and starts to wipe at it with a damp cloth. Cleaning away the blood with quiet fervor, unsure just what could inflict such a wound on his Sergeant at this hour of the night. When the wound is revealed he flinches back.
Ghost is intimately acquainted with snake bites, has several scars buried deep in his collection that match the marks on Soap's arm, stretched and warped as they are from where he's grown since he got them.
And this is from a big fucking snake.
He looks up to Soap meets his eyes suddenly deathly sober.
"Just how'd you get this Soap?"
257 notes · View notes