#dermal denticles

[dyingstars-if]

i was today years old when i learnt that whale sharks have teeth on their eyeballs.

[neil-gaiman]

Did you know that whale sharks have tiny teeth in their eyes :)

I didn't. I do now. Amazing. Thank you!

[montereybayaquarium]

While shark teeth tend to get a lot of attention, it’s the teeth on their skin that you should brush up on! Shark skin is covered in tiny, flat pointed scales that are called dermal denticles—which literally means skin teeth. If you look at a shark’s skin under a microscope, you’ll see that the scales are a series of overlapping teeth that result in a rough texture.

These pointed scales reduce drag on sharks as they swim, making them stealthy and fast as they cut through the water. This jagged texture also keeps fouling animals (like barnacles) from being able to settle on their bodies and slow them down, which is helpful when you’re a speedy top predator. 

TLDR: sharks are covered in tiny teeth and this makes them better swimmers. How’s that for a tantalizingly toothsome fact?

[fishyfishyfishtimes]

Daily fish fact #592

Bramble shark!

It swims just above the seafloor and vacuums smaller prey into its mouth. It has distinctive thorn-like dermal denticles!

[typhlonectes]

Whale Sharks Have Tiny Teeth on Their Eyeballs

The ‘dermal denticles’ probably help protect the eyes of these gentle giants, scientists say

Whale sharks are known as gentle, bespeckled giants that swim in tropical seas and scoop up plankton with their cavernous mouths. According to new research, they also have a sharp eye—literally: their eyes are covered in tiny teeth. The “dermal denticles” are modified, tiny teeth that cover the whale shark’s eyeballs, according to marine biologists from Japan’s Okinawa Churashima Research Center, who published their discovery in PLOS One Tuesday...

[best-sharks-bracket]

IM SORRY I FAILED HERES THE BETTER POLL

[uncharismatic-fauna]

A Stingray Abroad: The Broad Stingray

Bathytoshia lata is a stingray known by many names: the broad stingray, the brown stingray, and thorn tail stingray; Dasyatis lata, Dasyatis thetidis, and Dasyatis ushii. The species has accumulated all these names-- and quite a few others-- thanks to its broad distribution. It can be found in the Atlantic, Pacific, and Indian Oceans, as well as the Mediterranean sea. Typically the species stays on reefs or in coastal bays with muddy bottoms. Prior to 2012, genetic testing of stingray species revealed them to be populations of B. lata, hence the multitude of latin names.

The broad stingray is one of the largest species of stingrays; the average individual is about 1.5 m (5 ft) across and 56 kg (123 lb), with some populations reaching an excess of 2.6 m (8.5 ft) across and 290 kg (639 lbs). Females also tend to be larger than males. The body is diamond shaped, and the tail is often more than twice its length. B. lata is dark in color, often tan or black, with a white underbelly. Perhaps its most distinctive feature are the 'spines'-- also known as dermal denticles-- that line the tail and rear portion of the body, giving it the name 'thorn tail'.

The brown stingray is fairly docile, and spends most of the day lying inactive on the sea bed. At night they forage for crustaceans, polychaete worms, and small fish. They can use their powerful pectoral fins to burrow through the sand and uncover prey, and like sharks they have special organs called ampullae of Lorenzini that allow them to detect electrical fields emitted by their prey. The primary predator of B. lata is the hammerhead shark, and when threatened individuals will raise the spines along their tail to deliver whip-like blows.

Females become ready to mate in the summer, typically from November to March. Males are attracted to pheromones released by the female, and initiate a dance-like courtship ritual. If the female is receptive, he will bite down on her pectoral fins while grasping her with special claspers located at the base of the tail. Following the mating ritual, the female gestates her young internally for 10-12 months. This species is ovoviviparous, and the pups recieve nutirents from both a yolk and internally secreted milk. Following her pregnancy, the mother gives birth to live young, typically 3-4 in a litter. The pups are completely independent, and receive no parental care after being born. It takes them about 14-16 years to become fully mature, and individuals can live up to 28 years in the wild.

Conservation status: The broad stingray is considered Vulnerable by the IUCN. Its most common threat comes from being caught as by-catch in fishing nets, and intentionally for their meat and skin.

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Photos

Andy Murch

Sarah Speight

Andrew Green

Phillipe Guillaume

[eddieintheocean]

hello! do you have any whale shark/basking shark/megamouth shark facts?

this has been sitting in my inbox for a whole 2 months and i apologise

whale shark:

whale sharks are Fish, the largest fish infact

they have Teeth Eyes (dermal denticles: which are enamel plates that help protect their eyes)

basking shark:

the 2nd largest Fish!

they may display courting rituals! small groups have been seen swimming in circles nose to tail during summer months (these rituals may potentially last for up to 6 hours)

megamouth shark:

it was discovered in 1976, and around 120 specimens have been observed and studied

it was originally assumed that the white band of the megamouth's lip was bioluminescent, however a study in 2020 disproved this, suggesting that it was actually highly reflective due to denticles, and the light was reflected from the planktonic prey

[feelingautistic]

Can you give me a cool shark fact to tell my science teacher?

Whale sharks have a row of 'teeth' (with a similar structure to their dermal denticles) around their eyes often referred to as eye denticles that protect the shark from eye damage due to abrasion. Whale sharks are likely the only shark with this feature.

[sharks-are-friends-not-foes]

🦈 Daily Shark Fact: 🦈

A Knifetooth Dogfish's dermal denticles, which are teethlike structures on the surface of the body, have a stem-like base and broad, flat, leaf-shaped crowns on top with three horizontal cusps coming off their edges. They are found along the eastern Atlantic Ocean coast from Scotland to Spain, Portugal, and Senegal, at or near bottom at depths between 490 feet and 5,250 feet.

[howlingday]

Jaune: (In the shower, Sighs) Nothin' like a hot shower.

Jaune: First the shampoo. (Grabs bottle, Lathers hair)

Jaune: And now the toothpaste. (Grabs tube, Lathers skin)

Fun Fact! Shark skin, also known as "dermal denticles" are made of the same composition as shark teeth. This armor protects their bodies. However, recent studies have shown shark skin breaking down due to ocean acidification, a process similar to soda to teeth.

[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!!

[rinsvg]

જ⁀➴ # first date hc’s of Aran ojiro

જ⁀➴ # warnings; extreme fluff, cheek kisses, aquarium dates, js all around cheesiness .·°՞(≧□≦)՞°·.

First date Aran Ojiro who, with Kita's assistance and Suna and the twins butting in, took three weeks to ask you out and initially didn't fully comprehend why he was so scared. Until he was going to walk up to you when you were talking with your friend and realized you were so beautiful, that’s why he was scared. He ended up power-walking away that day when you turned to look at him, his face warm with blush.

First date Aran Ojiro who eventually worked up the confidence to approach you and ask you out on a date after many tries and failures. When he heard you laugh and nod, swore he could see the sun dancing in your smile and knew right then and there he would ask you out on many more dates if this one went well.

First date Aran Ojiro who took great care to ensure that every last detail of the date was planned. He didn't want to take you to the movies because he wanted you two to spend that time getting to know each other rather than sitting in silence for a few hours, and he didn't want to take you on a hike since he wasn't sure if you had any prior hiking experience. Up until that point, when he recalled that you had previously mentioned how much you adored young seals and manatees, he now had the perfect idea to take you to the aquarium.

First date Aran Ojiro who, when it was time to come and pick you up, brought flowers for you and your mother and who spoke to your mother for at least 15 minutes to reassure her that you would be safe and would return before the streetlights turned on. Who races to open the door for you before you could even reach the front door while your mother laughed at the two of you from the doorway of the kitchen.

First date Aran Ojiro noticed how happy you looked when the two of you arrived at the aquarium and knew this was the perfect decision. who kept staring at you as you told him interesting details about numerous sea species as he paid for your tickets, beaming with excitement.

First date Aran Ojiro who smiled when you asked him and turned to look at you. “Did you know that sharks have microscopic teeth all over their bodies called dermal denticles? Their skin is as rough as sandpaper because of this”. You applied pressure with your palms to the glass enclosures. "No, I didn't, However, could you please elaborate more?”. Aran asked while shifting slightly to you as you begin to explain some more.

First date Aran Ojiro who, after leaving the aquarium, took you to get ice cream, and as the two of you sat on the curb a short distance from the ice cream cart, the two of you began playing 21 questions while laughing at each other's questions and responses. "Okay, what would you name your autobiography if you had one?". Aran asked while wiping his mouth with a napkin. “Um, I’ll name it Love, y/n". You answered while biting into your cone, "Why love, y/n?" Aran asked while raising an eyebrow. "Because it’ll be like a love letter from me to whoever’s watching". You smiled while answering, and Aran laughed while smiling along with you.

First date Aran Ojiro who, with you in tow, arrived at your house five minutes before the streetlights came on. Who walked you to your door and stood with you there for at least 30 seconds trying to see how to ask if you guys can go on a second date while also wondering if this one went okay. Who squeaked slightly in surprise as you lean forward and kiss his cheek while saying "Same time Next Friday, okay". Before walking into your house with a smile on your face while looking back slightly to wave a goodbye at him.

First date Aran Ojiro who, despite likely never admitting it, walked home with a smile on his face and a little hop in his step.

જ⁀➴ # tagging; Here go your daily dose of love @digitalreblogs @punkologist

© rinsvg no plagiarism and modification of any kind or I will send down the Calvary.

[fishyfishyfishtimes]

Daily fish fact #701

Ninja lanternshark!

The ninja lanternshark is most well known for its camouflaging ability, using its black colouration and its tiny glowing photophores on its head to blend in the deep sea. It also has a significant amount of dermal denticles on its face and around its eyes, like armour!

[spontaneousmusicalnumber]

Can I have a weird animal fact plz

Wanna hear about SHARKS and EARLY EMBRYONIC DEVELOPMENT and COMMON CULTURAL MISCONCEPTIONS?

And no, it's not that some species will eat their siblings before birth, though that does happen. If you're not an only child, be glad you're not a sand tiger shark.

Anyway, we're mostly talking about teeth. Now teeth, despite common cultural mindsets, aren't actually bones.

Bone is made of, well, bone: Most of your long bones have a rigid, dense layer outside (Cortical bone) and a spongy, lighter layer inside (cancellous bone), and a space inside for marrow and other tissues. Your bones aren't hollow, why waste that space when you could be making blood cells in there?

Teeth, on the other hand, don't have any actual bone inside. The outer layer, enamel, is the hardest thing in our bodies, which is one reason teeth are so easily fossilized. If our teeth were actually bones, then we'd be gumming our food by the time we're twenty.

I know some of you are asking: But, but, how do we know teeth didn't start out as bones and just got super specialized over time? I'd say, great question! We know they didn't for two main reasons.

Teeth come from a different embryonic layer than bone. Embryogenesis gets pretty complicated, but I'll try to explain it simply.

Back when you (and every animal) is first conceived, you start life as a single cell called a zygote, then that divides into a solid ball of cells. That ball of cells keeps dividing and becomes hollow inside. Then at some point, like sticking your thumb into the clay to make a little bowl in elementary school, a hole forms and the hollow ball of cells folds inside of itself to create some layers. Now look at you! You've got three layers of cells! You've got an outside, or ectoderm. You've got an inside, or endoderm. And you've got the cells between your inside and outside, or mesoderm.

Each layer of cells gives rise to different parts of you. The endoderm mostly makes the inner lining of your digestive tract. The mesoderm makes most of your insides, including your bones. And the ectoderm makes your skin and eyes and outsides, including your teeth.

We also know teeth aren't bones because teeth evolved before true bones. Sharks and their kin have well-developed teeth with enamel, but they don't have any mineralized bones in their bodies. Even their jaws aren't true bone, but an evolutionary precursor. It takes a whole different leap of evolution to add full-body mineralized bone to the vertebrate repertoire!

Now, let's bring some things together. Sharks, though we love to sing their smooth praises, have skin that has been used throughout history as sandpaper or protective coverings. This is due to a layer of dermal denticles covering the skin- note that I didn't say scales! Scales evolved from dermal bone, or thin plates of bone arising from the ectoderm layer. These structures aren't bony at all, they're made of a different material: enamel. Yep, the same stuff in teeth. Yep, arising from the same embryonic layer as teeth.

This entire post has been a very roundabout way of saying that teeth aren't bones, and shark skin is actually covered in teeth.

(While in good fun, this is an educational scientific post. I ask that you do not continue the smooth sharks joke here.)

[druidposting]

Fun irl analog for the Slithers from last night is the skin of sharks. Shark skin is made up of dermal denticles, which are tiny interlocking plates of dentin scales - essentially skin made of tooth material. Given the slithers were already giving shark vibes, Id reckon Matt took this piece of real world biology and expanded it to be even more alien