#placoid

[protectoursharks]

There are four types of fish scales!

Cycloid scales are thin, overlap, and flexible. They're found on primitive teleosts (like minnows and carp).

Ctenoid scales have small, backwards pointed scales (known as cterns) make the fish more hydrodynamic and faster. They're found on Advanced Ctenoids (like perch and sunfish).

Ganoid scales are thick, diamond-shaped, and mostly non-overlapping. They're found on Chondrostei (like sturgeons and paddlefish).

Placoid scales are spikey and tooth-like with nerves. These are found on Chondrichthyes (like sharks and rays).

Ichthyology Notes 3/?

[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.

[t00thpasteface]

I Have Seen Your Tags on the supershark/"shark kent" post and i agree (1) "smooth sharking" is absolutely a thing people do about superman once word gets out about his (too-fine-to-be-immediately-visible) placoid scale situation, and (2) other people in bruce wayne's life absolutely troll him with it and he takes the bait every time because he HAS to correct people. he refuses to just roll over and say Yeah He's Smooth Actually. he'll just grapple-gun out of the room if you try to bring it up after a certain point

[i-should-have-studied]

Mod 2 General Topics

Types of Fins

Fins are thin, broad folds of integument internally supported by fin rays, they aid in locomotion in various ways depending on the type of fins.

There are 2 kinds of adult fish fins: unpaired median and paired lateral.

Unpaired median fins include 1-2 dorsal fins along the mid-dorsal line, a ventral anal fin behind the anus/cloaca and a caudal fin around the tip of the tail.

Paired lateral fins include pectoral fins anteriorly and pelvic fins posteriorly. Pelvic fins are called thoracic when located below the pectoral fins and abdominal when located just above the anus. Absent in some.

Under unpaired fins there are many types of caudal fins. Caudal fins are well developed in most fish because of its important contribution to forward propulsion during swimming. The 3 main types are: diphycercal, heterocercal, and homocercal.

Diphycercal Fins:

The most primitive, not exhibited by many living fish.

Vertebral column extends straight back to the tip of the tail, dividing the fin symmetrically and equally into the dorsal and ventral lobes.

Occurs in cyclostomes, primitive sharks, and lungfish.

Presence of diphycercal tail in developed fish is due to secondary modifications.

Heterocercal Fins:

Intermediate type.

The caudal fin is strongly asymmetrical.

Vertebral column bends upwards and reaches up to the tip of the more prominent dorsal lobe.

Characteristic in bottom feeders with a ventral mouth, the stroked of the large dorsal lobe directs the fish downwards.

Occurs in modern sharks.

The opposite, a large ventral lobe, is found in flying fish to propel them upwards. This type of fin is called hypocercal.

Homocercal Fins:

The most advanced type and the most common.

Characteristic of most higher bony fishes.

Externally symmetrical but internally asymmetrical.

The original dorsal lobe or epichordal is suppressed, the original ventral love is developed into a single or 2 symmetrical lobes.

Characteristic of fishes with a terminal mouth, its strokes force the fish straight forward.

Types of Scales

There are 5 types of dermal scales: Cosmoid, Placoid, Ganoid, Cycloid, and Ctenoid.

1. Cosmoid Scales:

Does not occur in living fish, only fossilized fishes.

2. Placoid Scales:

Characteristic of sharks.

Each scale has a backwardly directed spine arising from a round or rhomboidal basal plate embedded in dermis.

Spine is enamel-like and basal plate is of dentine-like bony material.

A pulp cavity inside the spine opens through basal plate.

Placoid scales are closely set together in skin; giving a sandpaper like texture.

3. Ganoid Scales:

Thick, rhomboidal, or diamond shaped plates closely fitted side by side. Tile like, provide a bony armor to the fish, might overlap in some.

Characteristic of holosteans.

4. Cycloid Scales:

Thin, flexible. translucent plates. Circular in outline and thicker in the center.

Marked with several concentric lines of growth which can be used to determine age.

They overlap each other, each scale is embedded in a small pocket of dermis.

Found in lung fishes, carp, cod, etc.

5. Ctenoid Scales:

Similar to cycloid scales in form, structure, and arrangement.

But is more firmly attached, their free hind parts with are not overlapped, bear numerous small comb-like teeth or spines.

Characteristic of modern higher teleosteans like perch and sunfish.

There are some intermediate types of scales found in between cycloid and ctenoid, and some fish like flounder have both.

Neoteny and Paedogenesis

Neoteny refers to the retention of a larval or embryonic trait in the adult body. For example the retention of larval gills in adult salamanders.

Paedogenesis refers to the development of gonads and or production of young by an immature larval animal. Examples are scattered in several groups or animals such as gall fly, liver fluke, and salamanders.

Neoteny emphasizes the retention of larval traits in the adult body while paedogenesis stresses the development of adult like gonads in the larval body.

The best example of neoteny and paedogenesis is ambystomata. Normally they live through an aquatic larval stage and transform into an air-breathing terrestrial adult. However, under certain circumstances, the larvae does not undergo metamorphosis, retains it's gills and aquatic nature, but becomes sexually mature. This sexually mature larval stage with external gills is called an axolotl.

For a while axolotls were thought to be an entirely separate genus, Siredon.

Environmental factors affect metamorphosis in many ways. Abundance of food, cold temp., and insufficient iodine may cause failure of metamorphosis and paedogenesis. This is known because drying of swamps, lack of food, and rise in temp induce axolotls to metamorphose. When treated with thyroxine or TSH, they lose their gills and become adults.

There are 3 types of neoteny, partial, intermediate and total.

Partial neoteny is then metamorphosis is delayed due to temporary ecological or physiological changes, seen in tadpoles over winter.

Intermediate neoteny is when the organism is sexually reproductive and can undergo metamorphosis under the correct conditions, seen in axolotl.

Total neoteny is when they remain larval throughout. Even after treatment of thyroxine, they fail to metamorphose. Seen in Siren.

Parental Care in Amphibians

Parental care is the act of looking after the eggs or young until they are independent enough to defend from predators.

Amphibians exhibit various types of parental care in two broad groups: Protection by nests, nurseries, or shelters and direct caring by parents.

Protection by nests, nurseries, or shelters:

1. Selection of site: Many amphibians lay their eggs in protected moist microhabitats. Some frogs and toads lay eggs on land near water. Many tree frogs lay their eggs on leave and branched overhanding water by gluing their eggs, they fall into water free of predators when hatched. Some tree frogs deposit eggs in water that accumulates in epiphytic tropical plants, free from aquatic predators.

2. Defending eggs or territories: Male green Rana frogs maintain territories and attack small intruders to protect the eggs. Both male and female Mantophryne frogs guard the eggs. The male actually sits over and holds the gelatinous envelope containing 17 eggs.

3. Direct Development: In some frogs such as Hyla, the eggs hatch directly into little frogs, thus avoiding the chance of larval mortality. In the red backed salamander, the hatchlings are miniature adults.

4. Foam Nests: Many amphibians convert copious mucous secretion into nests for young. Japanese tree frogs dig a hole or tunnel into which eggs are left in a frothy mass to avoid desiccation. During rain, the hatching tadpoles are washed down the slopping tunnel into pond or river water for further development. Some frogs lay eggs in nests of foam floating on water. The female emits a huge amount of mucus that she can beats into foam with her hindlegs to lay eggs in. When tadpoles hatch they drop from foam into water.

5. Mud nests: Brazilian tree frog, Hyla, the male frog digs little holes in the mud of shallow water for the female frog to lay eggs in. The nest is 30cm in diameter and 5-8cm deep. Tadpoles hatch within this safe place and develop until they are large enough to defend themselves.

6. Tree nests: The South American Tree frog, Phyllomedusa, lays eggs in a folded leaf nest with margins glued together with cloacal secretions. The tadpoles when formed fall straight into water below.

7. Gelatinous bags: Salamandrella, a small aquatic salamander, deposits 50-60 small eggs in a gelatinous bag which is fastened to aquatic plants.

Direct Carrying By Parent

1. Coiling around eggs: In certain caecilians like Ichthyophis, the female lays large eggs in burrows in damp soil and carefully guards them by coiling her body around them until they hatch.

2. Transferring tadpoles to water: Some species of small frogs in tropical Africa and South America deposit their eggs on ground. Once the tadpoles hatch, they fasten themselves to the back of one of the parents with their sucker like mouth so they can be transported to water.

3. Eggs glued to body: Many amphibians carry the eggs glued to their body. In the Sri Lankan tree frog, the eggs are glued to the belly of the female. In the European midwife toad, Alytes, the mall entangles the eggs around his hindlegs so he can carry them with him until they are ready to hatch. When the time comes they release the tadpoles into the nearest water body.

4. Eggs in back pouches: In a group of tree frogs called marsupial frogs, the female carries the eggs on her back. Either in an open oval depression, a closed pouch, or individual pockets. The eggs develop into miniature frogs before leaving their mother's back.

5. Organs as brooding pouches: Males of the terrestrial South American Darwin's frog, Rhinoderma, pushes at least 2 fertilized eggs into his large vocal sacs. There they undergo complete development to emerge out as fully formed froglets.

6. Viviparity: Some anurans are ovoviviparous. They reatain eggs in the oviducts and the female gives birth to living young. For example African toads give birth to little frogs.

[gamerwoman3d]

I didn't respond directly but someone was irked that Wolverine's teeth were white when the rest of his skeleton is laced with adamantium. It made no scientific sense to them.

Anyway teeth are just an evolution of a placoid scale and scales grow back if you break 'em. Humans get two sets of teeth before we naturally inhibit their regrowth, but theoretically we can turn off the inhibitor and just grow a 3rd, 4th, 5th set of teeth in our lifetimes. So his teeth probably have regeneration/healing factor just like the rest of him.

If Stryker HAD laced them with adamantium, knowing the teeth aren't a permanent part of his physiology, it's likely that someone, Logan included, could have just broken them out and used them as tiny little adamantium tools of some sort.

While Logan with an adamantium grill might look cool, it's more realistic for his teeth to look... brand new. Like uncannily, eerily brand new.

[diving-likea-snailfish]

Transdermaldenticle / Transplacoidscaled

A transbody / transid in which one believes they should have Dermal Denticles / Placoid Scales

[amethystpearl222]

scalecare routine when?? 👀👀👀

depends on ur scale type!!!! and im not a pro but my tail is pretty shiny despite all the swimming i put it thru lol

here is my full mermaid tail/scalecare routine (siren friendly!)

for placoid scales, daily rinse: use a gentle sea cleanser. weekly buff: Pearl or seashell scrub for a smooth touch. monthly mask: Kelp mask for deep hydration!!!!

for cosmoid scales, daily wash: go for a pH-balanced cleanser. gentle and easy. weekly tone: seaweed toner to balance things out. keeps your scales happy and fresh! & u can also occasionally do a marine collagen mask!!

for ganoid scales, to daily clean: use a mild cleansing gel. feels as fresh as your morning ocean swim! weekly polish: sea minerals scrub to keep things smooth. monthly boost: marine protein treatment. strengthens your scales!!!!!

for both cycloid & ctenoid scales, daily wash: mild cleanser follow w/ daily hydration: light seaweed moisturizer. keeps your scales flexible and glowing. weekly exfoliate: enzymatic scrub for smoothness. Monthly Refresh: Marine botanical mask.

[sharks-sharks-sharks]

Sharks are like so cool, did you know that sharks' skin is made up of dermal denticles, these are miniscule placoid scales that are similar to teeth, these dermal denticles are even covered in enamel, called vitro-dentine, and they also include dentine and a pulp cavity, which again makes them very comparable to teeth! Sharks are just silly little guys hehehshe!!

[ntls-24722]

THE 5 IMMOBILE SUBSPECIES!!!!

87 million years is a long time, and while their planet is smaller after the extinction event, the low gravity leads to some CRAZY topology and land barriers and they have evolved into a bunch of seperate subspecies.

The main Sexy Accent colors are yellow-orange-red but the arid subspecies actually uses their blue blood, close to the surface of their outer sheen to create those markings, not just to be ~hot~ but also to cool themselves down. Their dewlaps have similar blue streaks when the skin is thinner for the exact same reason

The polar and aquatic immobiles have those spiky scales for their necks because they're meant to reduce drag in the water much like sharks' placoid scales. The polar ones are also semi-aquatic and are terrifying because they're evolved to eat their equivalent of whales which are fuckin water kaijus

[hazbinsponsoredbyvee]

Huh, didn't know sharks didn't have bones-- Did ya know sharks skin also feels similar to sandpaper? Just found that out and thought it was fun :D

:] anon

"Yep, their skeletons are purely comprised of cartilaginous tissue. And yeah, the reason for the sandpaper feel is because their skin is made up of placoid scales that help to reduce friction from the water."

[v4ll3y]

Day 1: Elasmobranchology

Elasmobranchology is the study of modern sharks, sawfish, skates, and rays, also known as the subclass Elasmobranchii and class Chondrichthyes.

These cartilaginous fish are characterized by having five to seven pairs of gill clefts opening individually to the exterior, rigid dorsal fins and small placoid scales on the skin. The teeth should be layered and their jaw is never fused with their cranium, though the difference between jaw anatomy vary between species. Elasmobranchs do not have swim bladders and instead rely on large livers rich in oil to maintain buoyancy. Some deep sea sharks are targeted for this liver oil, including the school, gulper and basking sharks. All three have been assessed and are now confirmed to be threatened with extinction due to overfishing.

Let me know if you have a specific class/subclass you'd like me to do next :)

[professor-dr-kujo]

Daily Ocean Fact #19:

A shark's skin feels like sandpaper due to the fact that it's made up of tiny-like structures called placoid scales. They are also known as dermal denticles.

[bestanimal]

Round 1 - Phylum Chordata

(Sources - 1, 2, 3, 4)

Chordata is a phylum consisting of bilaterial animals that have, at at least some point in their development, a notochord and a dorsal nerve chord. It consists of the Cephalochordates (lancelets), Tunicates (sea squirts, salps, and larvaceans), and Vertebrates.

Vertebrates replace their notochord with a spine in early development, while tunicates only retain their notochord and dorsal nerve chord during their larval stage. Vertebrates and tunicates are more closely related to each other than they are to lancelets (first image), which are fish-shaped filter-feeders. They typically inhabit the sea floor, burrowing the bottom halves of their bodies into soft substrate. They have gill slits, but these are used for feeding on plankton rather than respiration. They have light-sensing organs, and one frontal eye. They do not have hearts or brains. They have two sexes, though hermaphroditism has been observed, as well as at least one instance of a lab-raised female transforming into a male. They breed by releasing eggs and sperm into the water synchronously. Larvae are asymmetrical, with the mouth and anus on the left side, and the gill slits on the right side.

Most tunicates are also filter-feeders, ranging from the sessile, sponge-like sea quirts (second image) to the planktonic salps. All tunicates start life as free-swimming, tadpole-like larvae with rudimentary brains and light sensors, before they metamorphize into their adult forms. Meanwhile, the larvaceans retain tadpole-like shapes and active swimming all their lives. Salps move by contracting, similarly to jellyfish, straining phytoplankton from the water. They have a complex life cycle, in which one generation of solitary individuals reproduces asexually by producing a chain of tens to hundreds of individuals, which are released from the parent at a small size. The next generation consists of a colony of salps (called blastozooids) remaining attached together while swimming, feeding, and growing. This generation reproduces sexually, first maturing as females and later transforming into males. Older chains of male blastozooids will fertilize the eggs of younger female chains. Growing embryos are called oozooids, and eventually detach from their parent blastozoids, to feed and grow as the next solitary, asexual generation. Meanwhile, some species of sea squirt live as solitary individuals, while others replicate by budding and become colonies of zooids. They are filter feeders with two tubular openings, called siphons, through which they draw in and expel water.

The most simple vertebrates are hagfish, which have a skull but no vertebral column. They are marine predators and scavengers who can defend themselves against larger predators by releasing copious amounts of slime from mucous glands in their skin.

Lampreys have an ambiguous position in the vertebrate tree of life, bearing a complete braincase and rudimentary vertebrae. They spend the majority of their life as filter-feeders. A small handful of species are known to be carnivorous as adults, boring into other fish to consume flesh and/or blood.

Chondrichthyes (“cartilaginous fish”) have skeletons composed mainly of cartilage. They breath through gills but lack opercula (gill coverings). They have internal fertilization and some species lay eggs while others give live birth. Chondrichthyans have tooth-like scales called dermal denticles or placoid scales. These usually provide protection, and in most cases, streamlining. Today, chondrichthyans are represented by sharks, rays, skates, sawfish, and chimaeras. All species are carnivores, though at least one species is omnivorous.

The majority of chordate species are Actinopterygians (“Ray-finned Fishes”). They are so called because of their lightly built fins made of skin webbings supported by thin bony spines. They are the most abundant free-swimming aquatic animals and can be found almost anywhere there is water. They come in a vast majority of sizes, shapes, colors, and behaviors, from the 8 mm (0.3 in) long Paedocypris to the 11 m (36 ft) long Giant Oarfish (Regalecus glesne). In most actinopterygians, males and females exist and reproduce through external fertilization. However, some species utilize sequential hermaphroditism, in which they start life as females and convert to males at some point. In a few species, they start life as males and convert to females. Some species give live birth, and some species self-fertilise. Actinopterygians have feeding strategies ranging from predatory to grazing to filter-feeding.

And lastly, the Sarcopterygians (“Lobe-finned Fishes”), named for the prominent muscular limb buds (lobes) within their fins. They are represented by the coelacanths, lungfish, and tetrapods. The vast majority of the rest of chordate species are tetrapods, a terrestrial clade of sarcopterygians who evolved air-breathing using lungs. They are highly diverse, with a large variety of forms, biological strategies, and ecological roles. Along with arthropods, they are the only other group of animals to have adapted to life in dry environments, and the majority of them live on land.

Chordata is one of the largest phyla of animals when it comes to species and is also one of the oldest phyla, known from as early as the Cambrian explosion.

Propaganda under the cut:

Lancelets naturally express green fluorescent proteins. They may use this green fluorescence to attract plankton towards their mouths.

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.

The Mangrove Rivulus (Kryptolebias marmoratus), a species of killifish, mostly breeds by self-fertilization and can survive for about two months on land. Males are rare, and can only hatch from eggs kept below 19 °C (66 °F).

The largest chordate is the Blue Whale (Balaenoptera musculus), which can reach a maximum confirmed length of 29.9 m (98 ft) and weigh up to 196 long tons; 219 short tons). While it’s not the longest, it is the largest animal known to have ever existed.

At least one of your favorite animals is probably in this phylum. Most of the animals people keep as pets are in this phylum. We are in this phylum.

I am tired, and there is no way I can write enough propaganda for this poll, so I trust you can supply your own.

[bethanythebogwitch]

Welcome back to the series where I talk about evey fish pokemon’s origins and their real-life inspirations, this time covering gens III and IV.  See here for gens I and II.

Staring off with Carvanha and Sharpedo. Carvanha is based on a piranha, specifically a red-bellied piranha.

"I'm mot really that scary" (image: a piranha)

When I say “based off of” I mean that in a pretty loose way. It really looks nothing like a piranha and more like an artistic depiction of a generic “scary fish”. Let’s talk about piranha because they are probably the world’s most slandered fish. Piranha are not the hyper-vicious super-predators that roam the Amazon devouring everything in their path that media depicts them as. They’re actually omnivores rather than obligate carnivores and mostly scavenge the dead. The stories of them attacking and skeletonizing large animals in minutes come from times when European explorers would be shown displays where schools of piranha would be trapped and starved for a long time to get them to act like that. Attacks on humans are rare and usually happen when the human gets too close to a piranha’s eggs, prompting a warning bite. If you still aren’t convinced that they aren’t fishy murder machines, check this video of River Monsters’ Jeremy Wade getting into a pool of hungry piranha and not getting bit at all

(this is not me telling you to go swim with piranha. Always be cautious when around wild animals)

Like piranha, Carvanha is much more dangerous in groups. Real piranha only school part of the year while Carvanha do it permanently. Carvanha is a river fish like piranha, but it also has a lot of shark features that fit its evolution. It can smell blood from far away (a feature of both piranha and sharks) and has the famous placoid scales or denticles of sharks. Evolving Carvanha causes it to go from bony fish to cartilaginous fish in the form of the franchise’s first shark. Sharpedo seems to be a generic shark similar to a great white (it even has countershading) but missing its back half. This is similar to the ocean sunfishes of family Molidae, most famously the Mola mola itself.

(image: scuba divers swimming alongside a mola)

This is funny because sharpedo, an active and very fast ambush hunter, could hardly have a more different lifestyle than the Molas, who are slow and mostly eat jellyfish. Sharpedo is also based on a torpedo, and in later games where it’s ridable it seems to function like a jet ski. Like sharks, Sharpedo has placoid scales that are exaggerated in its mega evolution and faces overfishing from people using its dorsal fin in food. Mega Sharpedo having denticles on the sides of its snout point to inspiration from the sawfish, a shark relative.

Easily one of the fakest-looking real fish (image: a sawfish)

Barboach is a loach while Whiscash is a catfish. Barboach seems to specifically be a pond loach, which buries itself in sediment to avoid danger (hence the ground typing), can sense changes in weather (a big deal in this gen), and are common food fish and aquarium pets. Loaches are long and skinny and have barbels like Barboach.

(image: a loach)

Barboach may also draw from the loach catfish, which is a catfish that looks like a loach, tying into its evolution. Wishcash may also be based on the loach catfish, but it look much more like a conventional catfish. Whishcash’s connection to earthquakes (both causing and sensing them) is inspired by a creature from Japanese legend. Namazu is a gigantic catfish living under the islands and guarded by a god who restrains it with a rock. When the god’s guard slips, Namazu thrashes about and causes earthquakes.

(image: a depicition of Namazu)

Both loaches and catfish have barbels that are used for sensing. These barbels help both groups of fish live in very murky water by making them less reliant on sight. Because of this, loaches and catfish can live in water with very poor visibility and lots of sediment in the water column. Barboach and Wishcash can likewise be found in very muddy water and other places of poor visibility, like caves. Them being found in caves in some regions may also reference blind, cave-dwelling catfish.

Feebas is a bass, though it’s more based on the story of the ugly duckling. Just like in the story, you start out with a ugly little creature and turn it into something beautiful. I’m going to be perfectly honest, I don’t really see much bass in Feebas, I think it’s based much more on Magikarp than a bass, who are often pretty powerful predators, something Feebas isn’t. like with Mgikarp, I won’t be discussing Milotic in this as I think it’s a sea serpent rather than a fish.

Ok so there is a good explanation for why a fish evolves into an octopus. I hoped I could find a good explanation for why a clam evolves into eels, but I simply have no explanation for the Clamperl line. Huntail and Gorebyss really have no connection to their pre-evo. I won’t talk about Clamperl since (and this is some high-level biology so I hope you can follow me) clams aren’t fish. Both final form are based on deep-sea eels and eel-like fish. Huntail seems to have some basis with the gulper eel as both are sit-and-wait predators with very large mouths, though Huntail is a more active predator as it does have some powerful teeth.

Turns out gulper eels are a lot goofier than you'd think (image: a gulper eel with its mouth inflated)

These teeth may draw influence from other deep-sea predators with massive chompers, like viperfish or the fangtooth. Its use of its tail as a lure is a reference to the various deep-sea fish that use bioluminescent lures to attract prey. This is an example of caudal mimicry, where an animal’s tail mimics something else to lure in prey. A cool example of this is the spider-tailed horned viper, which you should look up if you don’t like bugs, I promise it’s definitely not really creepy. Finally, Huntail’s general longness, color pattern, and crest are references to the oarfish, one of my favorites. This deep-sea longboi is a rare sight at the surface but is believed to be responsible for stories of sea serpents because of how huge they can get.

Long, long man! (image: an oarfish)

Gorebyss similarly has a complex origin for a very forgettable Pokémon. It seems to primarily be based on snipe eels, which are deep-sea eels with long, slender jaws.

(image: a snipe eel)

Gorebyss’s jaws are fused into a needle, which is similar to pipefish, a relative of seahorses with a very similar fused snout. Some inspiration could also come from the deep sea-dwelling long-nosed chimeras, some species of which have a long, conical snout very reminiscent of gorebyss’s head shape.

(image: a long-nosed chimera)

Unlike most of its influences, Gorebyss is an active predator and its habit of stabbing its prey with its snout and injecting digestive juices to slurp its prey dry seems to be in reference to spiders and mosquitos.

Hot damn, Hoenn has a lot of fish. The next up is Relicanth, which is a pretty straight-forward reference to the coelacanth.

(image: a rare picture of a wild coelacanth)

Both are very ancient fish thought to have gone extinct until they were rediscovered in modern times. This makes them examples of what scientists call a Lazarus taxon. Ceolacanths are pretty cool fish. Along with lungfish, they are the only surviving lobe-fined fish. These fish were separated from the more common ray-finned fish by having their fins seated on fleshy lobes extending from the body, usually with bones in them (lungfish have lost the bones). Also when I say that coelacanths and lungfish are the only surviving lobe-finned fish, that’s not exactly true. It’s a principle in taxonomy (the study of how groups of life are related) that you can’t evolve out of your ancestry. You belong to every group your ancestors belonged to, even if you started a new group they aren’t part of. Tetrapoda is the clade of four-legged vertebrates skeletally adapted for life on land and they evolved from lobe-finned fish. That means every mammal, reptile, amphibian, bird, and so on, including yourself, is a lobe-finned fish. Coelacanths are most famous for being rediscovered alive and seemingly unchanged when they were thought to have gone extinct millions of years ago. They are often called living fossils for how little they appear to have changed. This term is pretty misleading and many biologists don’t like using it. In fact the coelacanths of today are different than those that swam with plesiosaurs, pretty radically in some cases. Coelacanths are often used in arguments by cryptozoology enthusiasts for why their favorite  dinosaur/plesiosaur/megalodon/whatever could still be alive and unchanged today despite leaving no fossil record. However a fish remaining relatively similar to its ancestors due to living in a very stable environment that doesn’t have the selective pressures encouraging radical change is very different than an apex predator or massive reptile doing so in an environment that has undergone massive changes and multiple major extinctions. I’ll link a video for more on why the coelacanth is a red herring in these kinds of arguments.

Finally finishing out Hoenn we have Luvdisc, possibly the most unnecessary Pokémon ever. Someone please give this poor fish an evolution so it can finally have a purpose. Paldea gave us updates to Delibird and Dunsparce so it’s definitely possible for Luvdisc to get some love. Anyway, it’s a discus fish. These are thin-bodies cichlids whose dorsal and anal fins make them kind of look like hearts, though Luvdisc is missing the tail fin.

(image: a discus fish)

Like the discus fish, Luvdisc is a social species. Luvdisc's kissing behavior draws primarily from the kissing gourami. These fish engage in behavior where they press their mouths against each other. Scientists believe that this is a form of ritualized aggression, but people think it looks like they’re kissing so these fights have become a symbol of romance.

(image: two gouramis "kissing")

They aren’t the only fish that mouth fight. Another species that does this is the sarcastic fringehead, who looks considerably less romantic.

(image: two male sarcastic fringeheads fighting)

After the piscine flood in Hoenn, Sinnoh comes along and introduces a grant total of one fish line, though I will give an honorable mention to the Gible line for being shark plane dragons. Finneon and Lumineon are based on a variety of pretty fish often seen in aquariums, though their fish resemblance to butterflies indicates they are based on the butterflyfish. They have a much closer appearance to the freshwater butterflyfish than the more popular and unrelated saltwater butterflyfish. Both the freshwater butterflyfish and the Finneon line can glide above the water if they build up enough speed. The line’s bright colors may be a reference to brightly-colored tropical fish or aquarium fish like neon tetras. Lumineon actually bioluminesces to attract prey, but risks attracting predators at the same time, a behavior seen in many deep sea fish. it is said to dwell on the sea floor and walk on what I assume are its pelvic fins, which may be a reference to the deep-sea tripod fish.

That's it fro generations III and IV. Next time I'll cover generations V and VI. Hopefully it won't take me nearly as long to get that up.

[akorean]

I come to you with the shark facts I was too busy to give you all of!

Sharks have Placoid scales (scales that face one way meaning you can pet them one way but not the other) to reduce drag

Some sharks have only ram ventilation which is like breathing oxygen rich water through swimming into it instead of pulling it into their mouth. This means those sharks need to move to breathe

To help their Buoyancy and make it easier to not sink (they still sink if not moving tho) sharks have cartilage bones (less dense than regular bones), a big liver and a heterocercal tail- a tail with a bigger top fin than lower- which creates lift

They have Constantly Replacing teeth!

Theyre fusiform which is like the least drag making shape

Countershading which is different colors on the top half and bottom half letting them blend in both above them and below them

They also have good senses like smell! And more senses, they have sensors for vibrations and electroreception

:0 the shark facts!

Very interesting, thank you

Oh, can I also ask some stuff?

1. How do the sharks that have ram ventilation sleep? Is it like a dolphin situation?

2. Are the new teeth already in the gums like what we have , but times... a lot, or do they grow them when the old teeth fall out?

3. The scales are facing... the back of the shark, right? So you should pet the shark starting from the nose?

[saltysciencesixer]

Hiya! I have a fun science fact for you! Sharks are smooth. I hope you like my science fact!

"That is WRONG! How dare you smear science with your bullshit facts! Shark skin is rough, not smooth! The reason is because sharks are covered in tiny, teeth-like scales called dermal denticles or sometimes placoid scales! This has been known for YEARS! You're a complete disgrace!"