#Zone Control System | Explore Tumblr posts and blogs

no-passaran · 1 year ago

Text

Genocide experts warn that India is about to genocide the Shompen people

Who are the Shompen?

The Shompen are an indigenous culture that lives in the Great Nicobar Island, which is nowadays owned by India. The Shompen and their ancestors are believed to have been living in this island for around 10,000 years. Like other tribes in the nearby islands, the Shompen are isolated from the rest of the world, as they chose to be left alone, with the exception of a few members who occasionally take part in exchanges with foreigners and go on quarantine before returning to their tribe. There are between 100 and 400 Shompen people, who are hunter-gatherers and nomadic agricultors and rely on their island's rainforest for survival.

Why is there risk of genocide?

India has announced a huge construction mega-project that will completely change the Great Nicobar Island to turn it into "the Hong Kong of India".

Nowadays, the island has 8,500 inhabitants, and over 95% of its surface is made up of national parks, protected forests and tribal reserve areas. Much of the island is covered by the Great Nicobar Biosphere Reserve, described by UNESCO as covering “unique and threatened tropical evergreen forest ecosystems. It is home to very rich ecosystems, including 650 species of angiosperms, ferns, gymnosperms, and bryophytes, among others. In terms of fauna, there are over 1800 species, some of which are endemic to this area. It has one of the best-preserved tropical rain forests in the world.”

The Indian project aims to destroy this natural environment to create an international shipping terminal with the capacity to handle 14.2 million TEUs (unit of cargo capacity), an international airport that will handle a peak hour traffic of 4,000 passengers and that will be used as a joint civilian-military airport under the control of the Indian Navy, a gas and solar power plant, a military base, an industrial park, and townships aimed at bringing in tourism, including commercial, industrial and residential zones as well as other tourism-related activities.

This project means the destruction of the island's pristine rainforests, as it involves cutting down over 852,000 trees and endangers the local fauna such as leatherback turtles, saltwater crocodiles, Nicobar crab-eating macaque and migratory birds. The erosion resulting from deforestation will be huge in this highly-seismic area. Experts also warn about the effects that this project will have on local flora and fauna as a result of pollution from the terminal project, coastal surface runoff, ballasts from ships, physical collisions with ships, coastal construction, oil spills, etc.

The indigenous people are not only affected because their environment and food source will be destroyed. On top of this, the demographic change will be a catastrophe for them. After the creation of this project, the Great Nicobar Island -which now has 8,500 inhabitants- will receive a population of 650,000 settlers. Remember that the Shompen and Nicobarese people who live on this island are isolated, which means they do not have an immune system that can resist outsider illnesses. Academics believe they could die of disease if they come in contact with outsiders (think of the arrival of Europeans to the Americas after Christopher Columbus and the way that common European illnesses were lethal for indigenous Americans with no immunization against them).

And on top of all of this, the project might destroy the environment and the indigenous people just to turn out to be useless and sooner or later be abandoned. The naturalist Uday Mondal explains that “after all the destruction, the financial viability of the project remains questionable as all the construction material will have to be shipped to this remote island and it will have to compete with already well-established ports.” However, this project is important to India because they want to use the island as a military and commercial post to stop China's expansion in the region, since the Nicobar islands are located on one of the world's busiest sea routes.

Last year, 70 former government officials and ambassadors wrote to the Indian president saying the project would “virtually destroy the unique ecology of this island and the habitat of vulnerable tribal groups”. India's response has been to say that the indigenous tribes will be relocated "if needed", but that doesn't solve the problem. As a spokesperson for human rights group Survival International said: “The Shompen are nomadic and have clearly defined territories. Four of their semi-permanent settlements are set to be directly devastated by the project, along with their southern hunting and foraging territories. The Shompen will undoubtedly try to move away from the area destroyed, but there will be little space for them to go. To avoid a genocide, this deadly mega-project must be scrapped.”

On 7 February 2024, 39 scholars from 13 countries published an open letter to the Indian president warning that “If the project goes ahead, even in a limited form, we believe it will be a death sentence for the Shompen, tantamount to the international crime of genocide.”

How to help

The NGO Survival International has launched this campaign:

From this site, you just need to add your name and email and you will send an email to India's Tribal Affairs Minister and to the companies currently vying to build the first stage of the project.

Share it with your friends and acquittances and on social media.

Sources:

India’s plan for untouched Nicobar isles will be ‘death sentence’ for isolated tribe, 7 Feb 2024. The Guardian.

‘It will destroy them’: Indian mega-development could cause ‘genocide’ and ‘ecocide’, says charity, 8 Feb 2024. Geographical.

Genocide experts call on India's government to scrap the Great Nicobar mega-project, Feb 2024. Survival International.

The container terminal that could sink the Great Nicobar Island, 20 July 2022. Mongabay.

[Maps] Environmental path cleared for Great Nicobar mega project, 10 Oct 2022. Mongabay.

#shompen #genocide #stop genocide #india #indigenous #indigenous peoples #indigenous rights #human rights #anthropology #stateless nations #end occupation #andaman and nicobar islands #nicobar islands #great nicobar #💬#asia #geopolitics #ecocide #sustainability

23K notes · View notes

joyandella-123 · 1 year ago

Text

How Automation Affects Your Floor Space

One of the areas often overlooked when planning for automation is the way automation changes the floor space inside a metal fabrication company. It’s not exactly an issue of more space vs. less space, it’s a different way to use the same space. For example, you might have to think in a “cell” fashion rather than in a linear fashion, where next steps succeed each other literally down the line.

Here are some of the areas to consider when planning for automation, and the ways it can potentially change and make use of your space:

Efficient Space Utilization: Automated equipment can have a more compact and efficient design compared to traditional machinery. This can lead to better utilization of space, allowing more operations to be conducted in the same area. For example, automated storage and retrieval systems can utilize vertical space more effectively than manual storage. This three-dimensional thinking is still somewhat new in our business.

Reconfiguration of Layout: Automation may require a reconfiguration of the shop floor layout. Machines might need to be arranged differently to optimize workflow and accommodate automated systems. This might involve centralizing certain operations or creating specific areas for automated processes.

Reduction in Storage Space: Automation can lead to a reduction in the amount of space needed for storage. Automated systems often include just-in-time manufacturing processes, which minimize the need for storing large amounts of inventory on the shop floor.

Increased Safety Zones: Automated machinery might require additional safety measures, such as barriers or designated safety zones, which could take up additional floor space. This is necessary to ensure the safety of workers operating near automated equipment.

Decreased People Zones. Because of the additional cages and safety areas, “people” zones will shrink, and that must be considered when planning traffic through a shop. This is particularly true when considering the lanes for bringing 10 x 5 sheets of steel through the plant.

Room for Expansion: With automation, some processes become more efficient, potentially freeing up space that was previously used for less efficient processes. This space can be repurposed for new machines, expansion of existing operations, or for processes that are still manual.

Integration Space: If automation involves the integration of different machines and systems (such as conveyors linking different production stages), additional space might be needed to accommodate these integrations.

Space for Control and Monitoring: Automated systems often require spaces for control units, computers, and monitoring equipment. This might mean setting aside areas for control rooms or stations.

Potential for Scalability: Automated systems are often more scalable than manual operations. As the business grows, it might be easier to add new automated units or scale existing ones within the same space, rather than having to expand the physical footprint of the shop.

In summary, automation in metal fabricating can lead to more efficient use of space, require reconfiguration of the shop floor, increase safety zones, and potentially change storage and control needs. The overall impact on floor space can vary depending on the specific type of automation implemented and the existing layout and processes of the shop.

0 notes

gallusrostromegalus · 1 year ago

Text

The Van Has Officially Declared It Spooky Season

---

I've got my parent's van for the week and it seems determined to establish my status as The Local Cryptid by terrorizing an innocent 7-11 clerk.

...I might need to back up a bit.

My mother is an eminently sensible woman who knows herself well, and when The Plauge hit, she knew she'd need some sort of mentally and physically engaging craft project to keep herself from going insane and massacring the local zoning and water management boards (even if they have it coming). So she and Dad acquired a utility van and converted it into a camper van because while they love camping, they're past the age where their joints and immune systems will tolerate sleeping on the cold ground in a nylon tent.

They did a terrific job of it and my mom taught herself woodworking and carpentry and now the van has it's own cabinets, fold-away dining table, and removable queen-sized bed with memory foam mattress. My Dad was already a computer engineer, but he learned the dark magics of automotive software and electronics to install after-market backup cameras, a media player that would take a terabyte hard drive and a solar-powered battery and outlet so they could wake up and just turn on the kettle and griddle for breakfast without having to exit the van into a cold morning on an empty stomach.

Truly, the height of Camping Luxury.

My parents are both in their mid-seventies and my primary life goal is to be at least half as cool and hale as they are when I get old.

Anyway, they take it out at least a dozen times a year and it works fabulously, but, being as I am on good terms with my parents and also finishing the process of moving house, I've been borrowing it to move large and cumbersome objects that will not fit in the back of my equally lovely but minuscule Honda hatchback.

It's a Great Van. Very easy and comfortable to drive. Stunningly good MPG for it's size. The best cruise control I've ever had in a car.

It's just also. Quirky. Mischievous, even.

---

If this van has a fault its that it bears the unfortunate affliction that all lightly used white utility vans have in that the combination of an utter lack of branding features and the large dent/scrape I accidentally put on it while trying to escape a Denny's last Thanksgiving means that this vehicle is one addition of a Badly Spray-Painted "FREE CANDY" on the side away from being the sort of vehicle you see in an edgy horror movie.

It's got the same issue that Doberman Dogs have where they look like the sort of creature that likes to snack on toddler's faces whilst actually having personalities made of marshmallow fluff. This vehicle is unnecessarily menacing and I think nothing short of an airbrushed Epic Van Wizard will correct this. People see this van pull up and lean over and squint suspiciously at me when the driver's side door opens, and then look moderately confused when, instead of Charles Manson, a small, potato-shaped creature with neon purple hair and a statistically unlikely assortment of dogs emerges.

My own two dogs, Herschel the Hanukkah Goblin/Corgi and Charleston Chew The Taco Dumpster Dog, Do Not Like The Van. Even with the bed in it, they have a tendency to slide and roll around in the back, and both WILL chew through dog saftey belts or other attempts to secure them in there.

On the other hand, my house mate's dog, an exceptionally tall standard poodle whom we lovingly call "The Creature", loves the Van because SHE wears her doggy seat-belt with only mild complaining and gets to sit up in the passenger seat like A People.

Also like A People, The Creature likes to stand and walk around on her hind legs. It doesn't hurt her and it's entirely voluntary, but every so often I will feel a hand on my arm and instead of my husband or friend, it's a canine that's taller than I am on her hind legs who wants to stare at my face with soulful, concerned eyes. The Creature's favorite thing is that she is exactly the right height for me to hold her arm in Genteel Fashion and walk around the pet food or hardware store with her like I'm a count escorting a debutante around a royal ball.

---

As it stands, I am set to inherit this vehicle whenever my Honda gives up the ghost, and I fully intend to paint an Epic Van Wizard on it when that time comes.

The other peculiarity of The Van is that while Dad did manage to successfully install all his after-market electronics, not all the electronics get along. Sometimes, they fight for Dominance. The Terabyte Music Player and the Backup Camera have a particularly contentious relationship, and turning on the music has about a 25% chance of turning on the backup camera as well, and turning on the Backup Camera is equally likely to turn on the music.

Firthermore, The Van has a favorite song.

I am not kidding that Dad filled an entire terabyte hard drive with music and the software to sort it via the radio controls, but of all the Early Boomer Dad Rock (Kingston Trio over The Eagles) and Irish Folk and Symphonies and the entire discography of Weird Al Yankovic, The Van's favorite song- The one it picks to play as victory music every time it beats the Backup Camera at their weird electronic game of rock-paper-scissors -is The Liberty Bell March by John Phillip Sousa.

You all know this song already.

...but in case you've forgotten the tune:

youtube

Yeah.

The Van's favorite song is the goddamn Monty Python's Flying Circus Theme Music.

It does not play this song at a normal volume.

Every time I turn on the Backup Camera and it manages to turn the music player on as well, The Van insists on absolutely blasting this nonsense on at the maximum volume it's physically capable of producing, which I know is loud enough to be heard from the Denver International Airport's Pickup zone when they Van decided to start playing it from the economy lot about half a mile away.

Perhaps it's The Van's way of honoring the aesthetic sensibilities and sonic enthusiasm of Mr. Sousa.

...I can't help but wonder if the purpose of an Epic Van Wizard is to control this sort of faerie-like malarkey, and channel these chaotic energies into things like Spell of Don't Break Down In Nevada or Enchantment Of Always Have Good Parking.

---

So last Friday the 13th, I get a call from my friend and housemate, at said airport.

It's roughly 11PM at night, and I have already retired for the evening. I am in the exact minimum of clothing required to be a decent housemate and not scandalize the neighbors should I happen to walk by a window. My feet are up. There is a cat in my lap and fictional British people murdering each other in highly inventive fashion on the tv. -But my friend has returned from her friend's wedding,and either American or United Airlines has managed to lose her luggage, including, among other valuable possessions, the keys to her car. ...So she cannot just drive home as originally planned.

There are, as luck would have it, her spare set of keys not eight feet from me.

Being a good and decent person, I agree to bring the spare keys to her so she may get home before daybreak and not spend a semester's worth of tuition on an uber across the greater Denver traffic jam.

Being also that she Loves Activities, and it's her mom we're going to pick up, I elect to take along The Creature.

I am primarily focused on remembering how to get to the airport and not leaving my friend's spare keys on the counter, so I throw on a pair of flip-flops, step outside, remember that it's AUTUMN and my minimal evening attire is not sufficient thermal protection, step back in, grab the first coat in the closet I lay hands on, pull it on, check that I have her keys again and leave.

The trip to the airport is largely unremarkable, save that it becomes necessary for me to put on sunglasses to drive, despite it being nearly the witching hour and almost entirely darker than the inside of a cow.

It's necessary because this blissful darkness of night is violently punctured by a startling number of cars that seem to have installed miniaturized but no less powerful lighthouse bulbs in where their headlights ought to go so the oncoming traffic and sports cars that insist on tailgating me in the slow lane alike illuminate the road and my mirrors with the kind of radiance I'd normally associate with the arrival of a Seraphim.

I arrive at the distant highly discounted airport car lot where my housemate is waiting, deeply apologetic. It's nothing. I say. Once I see that your car starts up, I'm gonna go to that 7-11 across the way that I parked in front of, get a slurpee or something and I'll see you at home.

While she is retrieving her vehicle (an equally eccentric but much more stately Subaru that is old enough to be elected to congress) I rifle through the loose change in the glove box and discover that I have exactly $6.66 in small bills and coins. The Subaru, continuing it's long voyage into vehicular immortality, immediately starts up.

Upon her return, we all remember that my friend had all her camping gear in the backseat of the car and there is no room for The Creature to ride home with her parent, so I again assure her it's nothing, and will just take The Creature into the 7-11 with me. She is trained as a service animal and needs the practice after the plague.

I wave my friend off and turn to enter the 7-11.

I promptly trip over the jutting back bumper of The Van and fall, cartoonishly, face-first onto the sidewalk.

Fortunately, I have a lot of practice falling on my face, and have learned not to throw my hands out but instead cover my face, so my unexpected self-inflicted attempted curb-stomping lightly scrapes my hairline and nothing else -my sunglasses even stay in place- and I get up and resume my quest for a slurpee.

It's well known that the airport is a lawless place, and the 7-11 across from the discounted airport parking at the stroke of midnight is no exception.

I know it's the stroke of Midnight because there's one of those Audubon society bird-call clocks that makes bird noises, and my arrival is heralded by the twittering call of a Summer Tanager. I am almost charmed enough by the unusual choice of chronological device to excuse the exorbitant Airport-adjacent mark-up of Slurpee prices. I stand at the machine for some time, trying to decide on a size for the price and guess what the fuck "Blue Lighting Blast" is supposed to taste like.

The Creature is being Very Polite but is somewhat agitated, I assume because she *just* saw her mother for the first time in three days and then she LEFT with no explanation, so The Creature is on her hind legs, staring woefully into my eyes, asking to be escorted around the 7-11. Even though that's not what she's not supposed to be doing, there's nobody else in here, so I let her hang off my arm and discuss various Slurpee Flavor options with her.

We eventually decide on an experiment in which I try a Small Blue Lightning Blast, and discover it tastes a bit like licking a nintendo cartridge but in a pleasantly satisfying way.

I go up to pay and realize something is amiss.

The Cashier is a young man staring at me with wide eyes, one had over the register and the other wrapped up in his rosary.

I look down at myself.

In my haste to reunite my friend with her spare keys and service animal, I had left the house in the following accoutrements:

Flip Flops. Not matching. It's below freezing outside. That last part is not particularly odd footwear for the weather in for Colorado, but it's an important detail for the rest of the ensemble.

Assorted scrapes, bruises, cuts and welts on my arms and legs that come with doing outdoor work and living in a house with three dogs and a fully-clawed cat that all want to be in my lap all the time. It's cold out, so vasoconstriction has pulled the blood away from my skin, a trait that served my ancestors well during the last Ice Age, but leaves me with pale skin to contrast the various wounds and I look like a corpse that fell out of the back of a pickup truck.

The black Bootyshorts with "CRYPTID" painted in bright red gothic font across my ass, that @theshitpostcalligrapher gave me for my wedding present.

A peculiar but extremely comfortable garment that straddles the line between "Lacy Camisole" and "Industrial-Strength Sports Bra" like the Ever Given straddling the Suez Canal. It is also Bright Red. with black accents.

The Jacket I had grabbed out of the closet, which is in fact, a black Velour Dinner Jacket.

The Tokyo-Ghoul inspired reusable anti-covid mask a friend made me with the set of Coyote Teeth.

My sunglasses, which are shaped like a Halloween Bat. The lenses are the wings and the body is the nose bridge. It is ALSO bright red.

A Very Large and remarkably Humanoid Poodle that I have been audibly affectionately calling "Dear Creature" who is hanging off my arm like she's my Prom Date.

The Very Large and remarkably Humanoid Poodle is ALSO dressed up in a black Dog Sweater that has white bones printed on it to look like its an X-ray jacket showing off her skeleton.

I look like I am taking my Very Fancy Werewolf Girlfriend to a particularly casual Dinner Party for Vampires, but the thing that's really selling it and probably alarming the kid the most is the fun accessory I acquired in the parking lot not five minutes earlier:

The "Small Scrape At my Hairline" is actually a painless but PROFUSELY bleeding head wound that I had somehow entirely failed to notice covering my face, neck, decolletage and magnificent cleavage with blood like a Tarantino Film Extra.

This does explain why The Creature has been delicately trying to use her bodyweight to push me down onto the floor for the last ten minutes. So I don't injure myself while we wait for the paramedics she hoped this kid called to arrive, you see.

The Creature has such a High and Naive Opinion of humanity.

I decide this social situation is already fucked, and the only way out is through, and with haste, before I start dripping on the floor.

"Hi there!" I say cheerfully, to indicate this is a visually alarming but not terribly serious situation. "Just a Small Slurpee!"

The Cashier has entered the relevant code into the register before I finish the sentence. His gaze flicks off me just long enough to look at the total, and he grips his Rosary harder.

$6.66

"Oh cool! I have exact change!" I say, taking the money out of my as-yet-unsanguined pocket without looking and slap it down on the counter. "You have a good night and be safe out there!" I wave, leaving.

I get in The Van, mortified, buckle The Creature up, and as I make to leave, I have to put it in reverse, which automatically turns on the backup Camera.

It also turns on the music player.

I make eye contact with the cashier as the dulcet tones of John Phillip Sousa boom from the van hard enough to make the windshield and the windows of the 7-11 rattle for the nine-and-a-half seconds I have to wait to be able to turn the volume back down. Not knowing what else to to, I give him a thumbs up, and leave.

Anyway, now I know what my Future Van Wizard has got to be dressed like, and what their familiar is.

---

If you enjoyed this story, please consider donating to my Ko-Fi or Pre-ordering my Family Lore Funny Stories book on Patreon

#Family Lore #Dogs #It's Halloween babey #friday the 13th #blood mention #I hope that kid had a good night and at least one of his friends believed him #Long post #Video

16K notes · View notes

futureelctronic1180 · 1 year ago

Text

youtube

Signify MasterConnect LED lamps

https://www.futureelectronics.com/m/signify-north-america . Signify MasterConnect LED lamps offer high-quality retrofit LED solutions with a built-in wireless connectivity that are simple and easy to install. MasterConnect LED lamps maximize energy savings, while providing wireless and automated light for your comfort and convenience. With MasterConnect LEDlamps, your system is fully scalable and upgradable. https://youtu.be/o7XYHvGCT3k

#Signify #MasterConnect #LED lamps #retrofit LED #wireless connectivity #wireless #connected #automated #Interact #Philips #app #lighting system #programmed #automated occupancy #daylight detection #zone control #dimming #Youtube

1 note · View note

futureelectronic1527 · 1 year ago

Text

youtube

Signify MasterConnect LED lamps

0 notes

vmantras · 4 months ago

Text

Audi e-tron 55: The Future of Luxury Electric SUVs

₹1.25 Cr The Audi e-tron 55 Technology is a prime example of Audi’s vision for the future of luxury electric mobility. Offering a blend of premium design, state-of-the-art technology, and robust performance, this SUV caters to those seeking a sustainable yet luxurious lifestyle. Below, we provide a deeper analysis of its key aspects: Performance and Drive Electric Motor and Battery Motor…

0 notes

bethanythebogwitch · 4 days ago

Text

Wet Beast Wednesday: sea urchins

As I continue the slow grind of covering every living group of echinoderms for this series, it was inevitable that I would eventually encounter the only echinoderm I've actually studied. Sea urchins are among the most iconic of marine invertebrates, but many people just think of them as part of the scenery. I'm here to show you that there's more to these creatures than just being spiny lumps on a rock.

(Image: a purple sea urchin (Strongylocentrotus purpuratus) being held in someone's hand. It is a round, globular animal with a dark purple color. Light purple spines emerge from it all over its body, with the longest being around the middle. End ID)

(image: a long-spined sea urchin (Diadema savignyi). It is a black sea urchin with spines longer than its diameter. End ID)

Urchin is an old-fashioned word for hedgehog, and sea hedgehog is a fitting name for these round, spiny animals. Sea urchins tend to be fairly small, with a diameter of 3 - 10 cm (1 - 4 in), though some species have very long spines that make them seem larger. The main body of an urchin is round and enclosed in a (usually) hard shell called a test made of calcium carbonate. The test is covered with a slayer of skin and muscle that controls the spines and small, pincer-like structures called pedicellaria. Within the test are the internal organs. As with other echinoderms, sea urchins are radially symmetrical as adults, with five segments arranged around the center like pizza slices. The two main body holes are found on the top and bottom of the animals where the segments converge. At the bottom is the mouth and at the top is the anus. Each segment also has a hole near the anus used to release gametes and one will have a larger pore called the madreporite, which is used to control the amount of water within the urchin's body. The mouth is a unique structure known as Aristotle's lantern, consisting of five tooth-like structures (one for each body segment) that interlock together and sharpen themselves. Behind the teeth is a rasping tongue.

(image: a close-up of an urchin's mouth, showing the Aristotle's lantern. It is a hole surrounded by a fleshy lip. Five spade-shaped teeth are emerging from the edge of the hole. End ID)

Internally, most of the body is taken up by the digestive tract and water vascular system. The digestive system lacks a stomach, with the esophagus attaching directly to the small intestine. The digestive tract forms a loop as it passes through the body. The water vascular system uses seawater to form hydrostatic pressure that moves the tube feet. All starfish, urchins, and sea cucumbers have tube feet, small, transparent, tentacle-like structures they use for movement. Tube feet are hollow and retracted into pores on the skin normally. To be used, they have to be inflated with water, which makes them stick out of the body, where they can be controlled with muscles. Tube feet end in suction cups that can be used to grab into structures around them. Seawater drawn in through the madreporite serves as the source of pressure needed for the tube feet to function. In urchins, tube feet cover the body and are used for locomotion, moving food to the mouth, and moving objects on or off the body. The main body cavity is filled with circulatory fluid that uses special cells to move oxygen and nutrients around the body. The nervous system is simple, consisting of a central nerve ring around the esophagus that branches into nerves that connect to the rest of the body. Urchins have no eyes (except for the family Diadematidae, which have eyespots), but are sensitive to light. The gonads are usually small, but during mating season they can swell to fill much of the body cavity.

(Image: a drawn diagram showing a cross-section of a sea urchin, with the different organs and body parts labeled. End ID. Source)

Sea urchins are found in oceans worldwide, from intertidal zones to the deep sea and the tropics to the poles. They are bottom-dwellers who feed primarily on algae, which they scrape up with their teeth. However, they will also take a variety of food, including carrion, aquatic plants, and other slow-moving or sessile animals like sponges, polyps, bivalves, worms, and sea cucumbers. Urchins can play a key role in regulating algae populations through their ecosystems, but they also rely on predators to keep from overeating necessary algae. Famously, California's kelp forests were almost destroyed by urchins eating the kelp after their primary predator, sea otters, were driven to near extinction. Urchin's primary defense against predators is their hard tests and spines. As most of the edible portion of the urchin is within the test, predators have to get through both layers of defense first. The spines are hollow and each can be moved independently of each other, allowing them to be positioned toward a threat. Many species contain venom within their spines as an added layer of defense. This venom is rarely dangerous to humans, but can cause swelling and painful reactions. Another layer of defense is the pedicellaria, which are good at removing small animals and parasites from the skin. The flower urchin, Toxopneustes pileolus, has modified its pedicellaria into flower-like structures that extend beyond the spines and can deliver a sting that can be fatal to humans.

(Image: a flower urchin. It is a pinkish urchin covered with flower-like structures that extend to the length of the spines. It has placed some bits of shells on top of it. End ID)

Sea urchins possess distinct males and females, though the differences are internal, making it impossible to tell which is which based on visual examination. During mating seasons, the gonads swell as they generate gametes. Urchins tend to reproduce in groups at synchronized times (possibly correlated with the phases of the moon in shallow-water species) to maximize the possibility of fertilization. When ready to mate, the gametes are squeezed to empty their contents through the genital pores and into the water column. Sperm must find egg in the water to fertilize it. Most sea urchins provide no parental care, but in some species, the female will retain the eggs in her spines to protect them. The eggs hatch into bilaterally symmetrical larvae called plutei that drift with the plankton. As they develop, a section of the larvae will develop into a radially symmetrical adult rudiment. This piece will eventually break off and become the juvenile urchin while the rest of the larva dies. Because echinoderms start out as bilaterally symmetrical larvae, we can infer that they developed from bilaterally symmetrical ancestors and the radial symmetry of adults is a more recent development.

(image: a series of photos showing the embryological development of a sea urchin from a single cell to a cluster of cells, to a bell-like structure, to growing several arms, to the eventual adult developing and breaking off. End ID. Source)

Fossils show that the oldest sea urchins had large, club-like spines that they walked on, with the modern spines being a later development. Most of those urchins died out with the dinosaurs, leaving the pencil urchins of order Cicaroida as the only living members. All other living urchins are Part of the clade Euechinoidea. Amongst them, there are still some oddballs, known as the irregular urchins of clade Irregularia. These urchins have moved away from radial symmetry, with less symmetrical segments and the anus and mouth moving from being on the top and bottom to being on the sides in the heart urchins. Heart urchins have gone from bilateral symmetry to radial symmetry and are now going back to bilateral symmetry. Heart urchin mouths don't have an Aristotle's lantern. Instead, they use strands of mucus to capture food and cilia to pull the strands back inside. Sand dollars, also known as sea cookies or sea biscuits, are also in this clade. These are flattened urchins with short and very fin spines that resemble velvet. They are burrowers who spend much of their time buried under sand and as such are rarely seen alive. The name sand dollar comes from their tests, which are similar to old dollar coins and can often be found washed up on beaches. While still radially symmetrical, sand dollars also have a secondary form of bilateral symmetry, with a distinct front and back end that often look different. Irregular sea urchins also tend to have fewer gonads and associated pores than regular sea urchins.

(image: a red pencil urchin (Heterocentrotus mamillatus) nestled among coral. Instead of spines, it has a series of long, thick, red clubs. End ID)

(image: a purple heart urchin (Spatangus purpureus). It is an urchin elongated on one direction and with a few rows of long spines amongst short ones. On the surface facing the camera is a large hole that could be the mouth or the anus. End ID)

(image: a group of irregular sand dollars (Dendraster excentricus) partially buried in the sand. They are round, flat animals with a velvety covering of tiny spines. The are sticking out of the sand. End ID)

Sea urchins have been known to humans for as long as people have lived near the ocean. Stings can occur when people step on them and can cause pain and irritation, but are rarely medically significant. That being said, some people can have allergies to the venom, which could be a big problem. Spines left in the wound should be removed, as they can continue injecting venom. Urchins are a food source for people around the world, specifically the gonads, which are the only meaty part of the animal. The gonads are often marketed as roe or corals and can be eaten raw or cooked. Urchins are also used as a model organism in embryology due to the interesting and well-studied nature of their larval development. Urchins are vulnerable to pollution, habitat loss, and over-predation. Ocean acidification due to climate change poses a major threat to them, as it reduces the quality of their tests.

(image: tow sea urchins served as food. They are upside-down with the bottoms removed. The gonads are visible within as five orange, spongy structures that take up most of the body cavity. End ID)

#wet beast wednesday #sea urchin #urchin #sea urchins #echinoderms #invertebrates #invertiblr #sand dollar #heart urchin #pencil urchin #marine biology #marine life #biology #zoology #ecology #animal facts #informative #educational #image described

700 notes · View notes