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Snake Fangs and Venom

July 21, 2023 by Clara

There are so many snake species in the world today. Surprisingly few are harmfully venomous (you can learn more about that here).

Venom is really toxic saliva mainly made up of proteins and enzymes. Different species of snake will have venom specialized for their preferred prey. That venom can be categorized into four types: Proteolytic (breaks down the area surrounding the bite), Hemotoxic (affects the cardiovascular system), Neurotoxic (affects the nervous system and brain), and Cytotoxic (affects cells near the bite).

Venomous snakes produce venom in their venom glands behind the eyes on either side. Specialized muscles surround the glands so the snake can push the venom down into the fangs and inject it into its prey.

There are four groups of snake teeth: Solenoglyphous, Proteroglyphous, Opisthoglyphous, and Aglyphous.

Aglyphous teeth are the usual non-fang teeth found in both venomous and non-venomous species.

Solenoglyphous fangs can be found in the viper family (viperdae) and are some of the most advanced fangs of any venomous snake. Solenoglyphous fangs are partially hollow so the venom can go down through the tooth and be injected into the prey.

Snake skulls are very unique; they are made up of many different bones only loosely connected, rather than how a human skull is fixed together. This allows snakes to move and stretch their mouths and allow for feeding on large prey. The viper’s fangs are connected to the maxilla which is hinged, allowing the snake to extend its fangs further than it could if they were fixed.

Proteroglyphous fangs are found in the Elapid family, like Solenoglyphous fangs, Proteroglyohous fangs are also attached to the maxilla but are fixed rather than hinged. The fang (or sometimes fangs) is much smaller than the vipers. So a snake with Proteroglyphous fangs will usually bite and hold on or chew to get the venom in. They have a smaller hole for the venom to travel through but often carry highly toxic venom, some of the most potent in the world.

Spitting Cobras in the genus Naja and Hemachatus are Elapid snakes with fixed Proteroglyphous fangs. They are able to eject their venom at a distance of four to eight feet because the hollow part of their fang angles to the front rather than straight down. So the venom comes out of the front of the fangs, where the snake directs it often toward the eyes of a potential predator. This is a defense mechanism rather than for use in capturing prey.

Here are replica skulls of a snake with Solenoglyphous fangs (to the left) and one with Proteroglyphous (to the right).

Opisthoglyphous fangs are also known as rear fangs. They have a small grove, with less potent venom, and can be found in Colubrid snakes. They are located behind the regular Aglyphous teeth, and the snakes have to chew on their prey in order to inject any venom. Snakes with these fangs are not of any danger to humans and are often classified as non-venomous, with the exception of the Boomslang (Genus Dispholidus). Colubrid snakes with these fangs do not have true venom glands, instead, they have Duvernoy’s glands, that produce some mild venom and lack the same musculature as true venom glands.

Curious how to tell if a snake is venomous or not? You can read more about that here, and take a quiz to see how well you can tell the difference.

Sources: LifeisShortbutSnakesareLong, ReptileKnowledge, Wikipedia, NationalLibraryorMedicine,

Filed Under: anatomy, Biology, Learning, Snakes, Uncategorized

Balancing Your Impact

July 15, 2023 by Clara

You may have heard people say that climate change isn’t that big of a deal; in fact, the climate is constantly changing. The last part of this is true. Over many millions of years, the climate does change, sometimes drastically. There are a few differences, though, between today’s change and the ones billions of years old.

One is that, before, with thriving ecosystems, there was lots of biodiversity, so there were more opportunities for life to evolve and continue. Two is the rate of change. Today the rate of change in our climate is ten times that than in previous events! You can see a graph of this on NASA here.

So what is causing this? There are so many things that come into play. It is good to know that the Earth is incredibly connected. It is sometimes even viewed as a living thing. So many different things come into play for its health.

Generating electricity may be the most widely used resource contributing to climate change. That, as well as transportation, has a major impact. The United States is one of the largest consumers of products that have a negative impact and has placed itself as one of the largest contributors to the warming climate and pollution. I would recommend you explore the graphs on this website. You can choose to view the graph as a chart, map, or table, and search by each country specifically if you’d like.

The meat and dairy industry is also a large contributor with a range of impacts. Pastures for these animals are one of the largest contributors to deforestation. The forests are not only homes to so much biodiversity, but they absorb carbon and are key to balancing our impact.

Naturally, animals produce carbon as we breathe. The earth is designed to sustain the amount of carbon that we produce as biological organisms. With all of the other sources we have created, however, it can’t keep up with the number of humans and the animals we have domesticated as food. These animals also consume a large amount of water and plant food.

Only 55% of the food grown in North America goes to people. The rest is fed to the animals we then eat. There are 9 billion people that need to eat every day. And we have about enough farmland to feed them. But 45% goes to the animals that provide far fewer nutrients for us. I’d recommend reading this interactive article by National Geographic about how to feed 9 billion people.

Humans are naturally omnivorous and eat a variety of foods including meat and a large amount of plant proteins. But if you think of true carnivorous animals like tigers, they only eat once every few days or even weeks. Foxes may eat meat daily, but they eat small rodents, and there are far fewer of them. No animal drinks the milk of another, especially a grown one. So it is so strange that now so many people rely on meat and dairy for food.

Meat and dairy is not a healthy option for everyday consumption anyway. It has been linked to a variety of diseases including cardiovascular disease and even cancer.

Often the animals are inappropriately housed and injected with a variety of chemicals to compensate. All of that gets into the parts of the animal you eat.

One of the best things you can do for your health and the health of the planet is just to reduce your meat and dairy intake to a few times a week or less. Eliminating meat and dairy from your diet doesn’t always mean healthy. That’s why “plant-based” is a better option. That means whole fresh veggies, fruits, grains, and legumes make up the majority of your diet. Processed foods are never healthy even if they are vegan.

Plastic is used in so many ways. And people use it so much. Fifty billion (yes with a b) plastic bottles are bought just in the United States. So much of the plastic we throw away ends up in the ocean, which is an important part of the planet for so many reasons, including the carbon absorbed by the phytoplankton.

Even if you do recycle, plastic can only be recycled so many times. And it doesn’t decompose. Most plastics break down into microplastics that often end up being consumed by animals, including us.

Unfortunately, this isn’t just stuff I’ve read online. I’ve been able to travel the United States since 2016, and have seen the meat and dairy farms, picked up trash on the beach, watched the slow disappearance of Lake Mead and Powell, and felt the heat rise just a bit every year.

The good news is that it’s not too late to balance our impact and live on a healthy planet. And you really can make an impact! Check out these stories, updated every month.

It doesn’t mean you have to go entirely vegan, plastic-free, and walk everywhere you go, either. The idea of “your carbon footprint” was pushed by the BP oil company to take the blame off of their impact.

Though there certainly is truth in being aware of your impact, there is only so much you can do when so many resources are based on something with a negative impact. Your political vote and where you invest your money can make a big impact on the future. Big companies often have the biggest impact, so you can consider your money as a vote and investment for the world you want to live in.

It’s not that difficult to reduce your impact, either. Here are some great resources that may open you up to a more sustainable world.

  • Using reusable bags and water bottles are a super easy way to save a lot of plastic from landfills.
  • When you use search platforms like Ecosia instead of Google, you can help plant trees with every search.
  • EarthHero is like an Earth-healthy Amazon store, where you can track the overall impact of the product throughout its lifetime, all the way to where it decomposes.
  • Using laundry detergent sheets is not only plastic-free, but so much easier to use, and takes up far less space than plastic bottles.
  • It’s easy to use a lot of plastic dog bags – here is a compostable version (don’t be confused with the EarthRated bags, they are not actually compostable)
  • Explore the Carbon Almanac and get emails from The Daily Difference to learn new ways to help.
  • Log onto the EarthHero app (different from the website listed before) to track your impacts and find new ways to make a difference.

Just educating yourself and being aware of your impact is so important. And sharing what you’ve learned and acted on with others is a really great way to start.

The biggest way to make a difference is with collaboration. Share what you’ve learned and how you are supporting sustainability in the comments!

Sources: OurWorldInData, NASA, UnitedNations, NationalGeographic, NationalLibraryofMedicine, IAEA, Britannica

Filed Under: Biology, Learning, Uncategorized

How to tell if a snake is venomous

July 10, 2023 by Clara

Out of 3,971 snake species in the world today, only 600 are venomous. To make this number even smaller, only 200 species around the world are considered potentially dangerous to humans and most of our animals companions.

Example of a species from the family Typhlopidae in the infraorder Scolecophidia. This is also known as a Blind Snake.

The suborder Serpentes is divided into two infraorders, the smaller group, Scolecophidia, describes 5 families of snakes, with species such as blind snakes. Many are fossorial (live underground) and therefore aren’t often seen. The other group, Alethinophidia, is the larger infraorder, with 25 families.

There are five families in the infraorder Alethinophidia that you should know:

  1. Elapidae: These are some of the most venomous snakes, like Cobras (Naja), Mambas (Dendroaspis), and the Inland Taipan (Oxyuranus microlepidotus), considered the most venomous snake in the world. Elapids closely resemble the colubrid family.
  2. Colubridae: These snakes are generally non-venomous or mildly venomous, and are the most common around the world. A few common species within the family are Rat Snakes (Pantherophis), Water Snakes (Nerodia), Racers (Coluber), and Garter Snakes (Thamnophis).
  3. Viperdae: A grouping of snakes that are usually shorter and wider with long venomous fangs. These include Rattlesnakes (Crotalus), Bush Vipers (Atheris) and Copperheads (Agkistrodon) to name a few.
  4. Boidae: Often smaller than their similar family Pythonidae, with the exception of the Green Anaconda (Eunectes murinus), which is considered the largest and certainly heaviest extant snake in the world. The biggest difference between boas and pythons is their way of reproduction. I will be doing a post about this soon.
  5. Pythonidae: A group of often large constrictor snakes such as the Burmese Python (Python bivittatus), Reticulated Python (Malayopython reticulatus), and Ball Python (Python regius).
Eastern Green Mamba (Dendroaspis angusticeps)
Black Racer (Coluber constrictor)
Eyelash Viper (Bothriechis schlegelii)
Green Anaconda (Eunectes murinus)
Burmese Python (Python bivittatus)

Snake venom is modified saliva, and the toxicity falls into more of a range than a strict formula. Similar to bee stings, the reaction can vary from person to person. With snake species in the Elapid and Viper family, the reaction to venom is almost always severe and should be medically treated.

However, some colubrid snakes, like hognose snakes and even tiny ringneck snakes, are also considered venomous. Their venom is mild enough that it is not harmful to humans, and they have small Opisthoglyphous fangs in the rear of their mouths versus the front, meaning an actual envenomation is unlikely. I have actually experienced an envenomation from my Western Hognose Snake (Heterodon nasicus), and can say that the venom is very mild. To read more about the interesting behaviors of genus Heterodon (hognose snakes), you can click here.

Remember if a snake is hiding, it will not emerge from its hiding place to bite a passing human that would put the snake in unnecessary harm. The only time a snake will attempt to harm a human is if it feels there is no other option, so as long as you do not step on or grab a snake, you (and the snake) will be safe.

Northern Cottonmouth (Agkistrodon piscivorus)

Snakes are an important part of the ecosystem; they are both predator to mostly rodents and amphibians, and prey to large birds and sometimes other snakes. And still, some people aren’t as excited to have snakes in their yard.

If you have a venomous snake in your yard, that means you are living on land that is suitable for snakes (hooray!), which means snakes will go and live there.

By killing or attempting to kill a venomous snake in your yard, you are putting yourself in unnecessary harm given that so many snake bites come when trying to kill a snake (obviously, the snake is desperately trying to save its life)!

If your yard is a good place for snakes, more will likely show up anyway. This is not to say that you should just stay safe inside, but rather be aware that there are always going to be other creatures all around you, and the best thing you can do to keep your yard free from snakes is to make sure there aren’t many places for them to hide. Things such as fallen limbs, tires, metal roofing, and hoses are all prime areas for a snake to be found. There are also lots of people around the world excited to help relocate snakes and share their passion (including me).

Eastern Coralsnake (Micrurus fulvius)
Loreal pit highlighted in Crotalus species. This is a Western Diamondback rattlesnake (Crotalus atrox)

It is impossible to identify all venomous snakes based on the same visual cues. Instead, you can learn to identify the different families of snakes and know which families are venomous. In North America this can be pretty easy; with the exception of copperhead and water moccasin species (both from the genus Agkistrodon), just about every viper species here has a rattle. They also have loreal or heat sensing pits between their eyes and nostrils. They also have a bulky body and large head. The only Elapid snakes in North America are the coral snakes. They have stripes and the yellow and red bands are touching.

A non-venomous Eastern Hognose Snake (Heterodon platirhinos) in a defensive posture.

But the colubrids (mild or non-venomous) are good actors and may mimic the colors and shapes of venomous snakes. For example, many colubrid snakes will spread out their flexible jaws to look like a venomous viper snake. And just about any snake you’ll come across will rattle its tail. Only rattlesnakes have true rattles, but all snakes may shake their tails when they feel threatened. This is not actually to mimic the venomous rattlesnakes, but it may have evolved simultaneously and even prier to the rattle snakes adaptation, you can learn more about snake rattles here.

There are rule breakers for every trick you may have heard, so the best way I have found is to pay attention to the whole animal rather than focusing on specific parts (like looking for the loreal pit in a rattlesnake or the bands in a coral snake). More often I’m paying attention to the head and body shape, as well as the body language and way of movement, because the pattern and color often varies between individuals within a species.

So here is a quiz that you can retake as much as you want that can help you become familiar with some of the common species you may see around North America. Go through it slowly and really pay attention to the images so that you can get to know the snake species. You can take it as many times as you want, and when you get the right answer I share where I found the snake as well.

Snakes are fascinating creatures, and, just like dogs, it’s important to respect their strength and their space, and pay attention to the body language. The more you know, the less there is to be fearful about.

Sources: NationalGeographic, Wikipedia, personal experience

Filed Under: Biology, Learning, Snakes

When Snakes Rattle

July 9, 2023 by Clara

There are two genera of pit vipers (Crotalinae) with rattles – genus Crotalus, with 51 species, and Sistrurus, with only three species. And they can all be found in the New World (North and South America).

Most of the Rattlesnakes that you’d think of come from the genus Crotalus. It includes Western and Eastern Diamond-Backs (Crotalus atrox & adamanteus), Mojave Rattlesnakes (Crotalus scutulatus), Sidewinders (Crotalus cerastes), and Timber Rattlesnakes (Crotalus horridus). While the smaller Pigmy (Sistrurus miliarius) and Massasauga Rattlesnakes (Sistrurus catenatus (Eastern) & targeminus (Western)), belong to the genus Sistrurus.

Eastern Massasauga (Sistrurus catenatus)
Mojave Rattlesnake (Crotalus scutulatus)
Timber Rattlesnake (Crotalus horridus)

Western Diamond-back Rattlesnake (Crotalus atrox)

There are a lot of misconceptions about Rattlesnakes. One being that you can tell the snake’s age by how many rattle segments they have.

Actually, Rattlesnakes are born with a first rattle segment, called a button (as seen in the image to the right). At first the button cannot make any sound and some biologists think it may be used as a lure.

Every time the snake sheds it gains another segment. It may take multiple sheds to get a fully developed segment, though. Snakes shed more often when they are young and slowly decrease the frequency of shedding as they age. Also, as the snake moves around, older parts of the rattle will likely fall off. In my illustration you can see how the segments interlock loosely enough to make noise.

Rattlesnakes aren’t the only snakes that rattle, though. Just about any kind of snake you’d encounter will shake its tail when it’s nervous. It is likely that the evolution of tail shaking may have effected many species of snakes around the same time, and was only specialized in rattlesnakes. In other words, when a non-venomous or venomous snake without a rattle shakes its tail, it is not trying to imitate a rattlesnake, because that habit evolved before the rattle did.

This beautiful Mojave Rattlesnake (Crotalus scutulatus) I found in Inyokern California. It is doing a great job of demonstrating a defensive posture and rattle.

I hope this helps you appreciate these fascinating animals. If you’d like to learn more about some strange defense strategies in snakes, you can read about the genus Heterodon here.

Sources: ResearchGate, Wikipedia, Britannica

Filed Under: Biology, Learning, Snakes

Genus Heterodon

July 9, 2023 by Clara

Hognose snakes are endemic to North America and can be easily identified by their turned up rostral scale. The rostral scale is the scale right on the tip maxilla (upper jaw). in Hognose snakes people often call it their nose, though their nostrils are actually a bit behind the rostral scale.

These snakes are terrestrial and use that shovel-like nose to burrow. There are four species of Heterodon, or hognose snake, Eastern Hognose (Heterodon platirhinos), Southern Hognose (Heterodon simus) Western Hognose (Heterodon nasicus), and Mexican Hognose (Heterodon kennerlyi)

Hognose snakes can be intimidating in the wild. When they feel threatened, they may puff up and hiss, flatten their necks like a cobra, and open their wide mouths. If you look closely you may even see their fangs.

If you approach any closer, they may rise partially above the ground and strike at you with a hiss. But the strangest thing of all is what happens next.

If you were to get any closer, the snake would release a musk, and roll over, playing dead.

You may be surprised to learn that snakes in the genus Heterodon are completely harmless to humans.

Even when they strike it is a bluff, where they actually have their mouths closed and just bump you with their rostral scale. It’s pretty funny to be head-butted by a hognose snake!

Hognose snakes are rear fanged venomous. They don’t quite have true venom glands with the muscles to push venom, nor hollow teeth to inject it into their prey. But they do have small opisthoglyphous fangs with a grove channel in the rear of their maxilla and, a Duvernoy’s gland that holds some semi-toxic saliva.

In the wild they prey on amphibians, so their mild venom delivered through the small Opysthoglyphous fangs in the rear of their mouths assist in feeding. They tend to have a special preference from toads and are immune to the toxins they secrete.

I have been bitten by my own Western Hognose Snake, Otis Mojave. It was not a defensive bite; he was just really hungry and my hand happened to be close by. It took a while for him to let go so I was envenomated, and only felt some mild itching and soreness.

The Western Hognose is a common species kept as pets. I care for two, Otis Mojave (right) and Ophelia Fawn (left). It’s so interesting to watch them and compare their morphology with my other snakes of different species.

Sources: Snakesarelong, Britannica, ScienceDirect

Filed Under: Biology, Learning, Snakes

Are your opinions of snakes really yours?

June 30, 2022 by Clara

Many people have a fear or disgust of snakes, but why? 

It’s scary not knowing where a potentially dangerous animal might be hiding.

All of a sudden you hear a rattling tail, or something slithers away faster than you can think!

Great Basin Gopher Snake (Pituophis catenifer deserticola)

When I bring up the idea of snakes in a conversation, the quick response is often negative. My Mom used to think the same way until she decided to let go of her fears. So many people seem to have this common fear, yet only 2% to 3% actually have a true phobia, known as ophidiophobia (according to the National Library of Medicine). 

Studies have shown that babies and young children have a stronger reaction and awareness to snakes (when compared to animals like caterpillars and frogs), but do not show any signs of fear around them. 

So it may be true that humans have developed awareness of certain animals during their evolution, but the only true fears that humans are born with is a fear of falling and a fear of loud noises. Any other fears are influenced by life experience, and, more often, the influence of others.

Most people don’t intentionally teach others to fear or hate snakes, but children pay attention to the actions and comments of others and often carry that with them throughout life.

Coachwhip (Masticophis flagellum)

In my experience, most people don’t have any real reason to hate snakes. Most often those people have rarely encountered or had any experience with them. And it makes sense – why would someone be curious if they’ve already been told all they think they need to know? If history has already placed them as “monsters”, that’s enough to keep many away. 

In the 13th century, when humans were beginning to classify animals, the study of herpetology (the study or reptiles and amphibians) was coming together, Vincent of Beauvais lumped reptiles, amphibians, and worms together, describing them as “monsters”. This idea of reptiles and amphibians as monsters continued for centuries. It was only in the 19th century that Latreille named the group of limbed amphibians batrachia, which separated reptiles and amphibians. This was the first step in caring about reptiles and amphibians separately, and for some disconnecting them from their title as monsters.

It can be hard to reason with people that have no reason for their beliefs, other than to ask that they approach the world with a more open mind. It doesn’t mean you have to like snakes or any other animal. But before you use that fear as an excuse, a reason to harm or harass an animal, or even as a connecting point with others, simply be curious. Try to find the root cause of your fear (if any) and research the science behind it. You’ll often find it to be less scary than it seems.

Southwestern Speckled Rattlesnake (Crotalus pyrrhus)

If the fear is that the snake might bite, you, you can easily learn that snakes will avoid biting as much as possible, often putting on elaborate defense displays. Even venomous snakes don’t want to waste their venom on something they couldn’t eat; they will only bite if they feel like there is no other choice. And even then, 50% of venomous snakes bites are “dry bites” where the snake doesn’t release any venom. (According to the National Library of Medicine)

If you really look into it, most snakes aren’t dangerous. There are 3,971 snake species in the world known today. Out of that, there are only 600 snakes that are considered venomous, and out of that, only 200 species are considered potentially harmful to humans. 

In the United States, there are 30 species of venomous snakes. There are no venomous snakes in Alaska, Hawaii, Rhode Island, and Maine.

North American Racer (Coluber constrictor)

Unfortunately, like so many animals, snakes are in danger of habitat loss, which forces them to find safety in areas populated by humans, where they are often killed by misidentification. Some people think it’s okay to kill a snake because they may be venomous and potentially harmful. However, this does not actually do much of anything to keep you safe. In fact, you are more likely to be harmed by a snake if you try to kill it than if you never knew it was there. It is estimated that people only see 1% of snakes they may encounter (this study was done with multiple pythons in an enclosure, so it could be even less), and so if you see a venomous snake and let it be, the chance of you ever seeing it again is slim. The only difference is that you know it might be there. Removing hiding places like trash and fallen limbs is a much better alternative to keep snakes away.

Whether you are aware of it or not, there are going to be snakes. And when a snake sees a potential predator (like you), they are going to be focused on surviving, meaning they do not want to be seen or caught. The worst thing a snake could do when trying to survive a predator is attack it. The symbolism of a snake’s ability to shed its skin can be a great reminder to let go of the past in order to grow into the future. 

So be like a snake and shed your fears.

Click here to dig deeper in this podcast episode with Mama Says Namaste!

Sources:

Wikipedia

National Library of Medicine

Live Science

Amphibian Foundation

Filed Under: Biology, Learning, Snakes

Cephalopods

October 27, 2020 by Clara

The name cephalopods come from the Greek root words for head and foot. Cephalopods are an advanced form of mollusk (snails, slugs, clams etc). Though many mollusks live in shell, moving around with their single foot, Cephalopods have evolved their one foot into the numerous tentacles that make them so unique. They are also known as ink-fish due to their unique ability to squirt ink out from their siphons.

Siphons are what cephalopods use to propel themselves through the water, and it is also where they expel their waste. The ink is used as a distraction; so any predators will go after it instead of the cephalopod. Most of the ink is actually made up of of the cephalopod’s mucus! In some species it can even cause harm to the sensory organs of the perceived threat.

Cephalopods have three hearts and copper-based instead of iron-based blood, causing it to be blue. They are very curious animals, but tend to stay away from other members of their species. If you haven’t seen the movie My Octopus Teacher, I would highly recommend it to learn more about the behavior of these amazing animals.

I have had my own similar experience with this at Bahia Honda State Park in the the Florida Keys. I saw a Caribbean reef octopus (Octopus briareus) in the marina by our campsite and decided to watch him/her for a while. I put my finger in the water above the octopus and after a few minutes he actually reached out a tentacle and wrapped it around my hand, trying to pull me into the water! It was an amazing encounter. Here is a picture I got afterwards.

Despite being able to change color, all octopuses* are colorblind. Many other Cephalopods are as well. There are over 800 species! Though mollusks can be found in many ecosystems, cephalopods only live in the ocean with only one species tolerant to brackish water (the Brief squid, or Lolliguncula brevis).

Most cephalopods have a cartilaginous (made of cartilage) cranium or shell around their brain, and cuddle fish have a version of hard structure called a cuttlebone that is made of aragonite crystal. You may find these in pet stores where they are commonly used for pet birds to chew on, as a way to supplement calcium.

Squid also have, in a way, an internal exoskeleton. It is similar in shape to a cuttlebone, but instead made of chitin, which is a major material found in arthropod exoskeletons.

Cephalopods are considered the most intelligent invertebrate on the planet. In captivity, they have been known to escape from the aquarium! In one case an octopus managed to make its way across the room into another aquarium with food, then climb up into that aquarium eat, and make its way back into their original aquarium!

You may have heard that octopi have a brain in each tentacle. Not all brains are the same; a brain is a concentrated mass of nerves, and different animals have somewhat different versions of the organ. Octopuses have some of the most well developed brains of any cephalopod, with a centralized system in the head, and prominent axial nerve cords in the tentacles.

Neon flying squid (Todarodes pacificus)

Because octopi have no bones, they are able to move their bodies fluidly and fit through about any space larger than their eyes. Squids and cuttlefish don’t quite have this same ability, but some squids have been known to fly!

The Neon flying squid (Todarodes pacificus), is a great example of this ability. They will use their siphons to propel themselves out of the water and flatten themselves out to glide through the air.

*If you’re wondering about the plural for octopus, both octopi and octopuses can be used. Octopi uses a Latin plural, but octopuses is correct in English. I find octopuses more often used in research articles, while octopi is more often used in conversation.

Sources: National Geographic, Britannica, Oxford Research, National Library of Medicine

Filed Under: Biology, Learning, the ocean Tagged With: all about cephalopods, cephalopod escape, Cephalopods, cuttlfish, do cephalopods have bones, do cuttlefish have bones, do squids have bones, flying cephalopods, flying squid, how many species of cephalopod, octopi, octopus, octopus escape, octopus ink, octopuses, squid, to octopuses have bones

How animals change color

October 14, 2020 by Clara

Animals have evolved to change colors for a variety of reasons. Mammals will change completely from brown to white during the changing seasons. The pineal gland (a part of the brain) detects the changing season and sends hormones to gradually change colors through seasonal shedding or molting.

As they shed their fur or feathers, the undercoat starts to come in white, and may be more dense to keep the animal warm. But these animals have little to no control over this process, just like we have little to no control whether we get freckles or grey hair.

Stoat (Mustela eminea)

One of the most well known color changers are chameleons! Their color changes are also controlled hormonally, but at a much faster speed than the seasonal changes found in some mammals and birds. it is a myth that they change color to blend into their surroundings. Instead, they use it to communicate their emotions and even regulate their body temperature!

Being ectothermic (commonly called “cold blooded”), chameleons would have a hard time controlling their body temperature without their ability to change color. When they are too hot, they will turn a lighter color, and when they are too cold they will become darker. How they do this though is all about the layers of their skin.

Many animals have color cells in their skin known as chromatophores. One type of chromatophore are iridiphores, the cells make blue and iridescent colors. Chameleons have many tiny nanocrystals in their iridiphores, that reflect wavelengths of light from their surroundings. Chameleons have two layers of these in their skin. When the chameleon is relaxed the crystals are closer together, and reflect smaller wavelengths like blue, and when the chameleon is excited or stressed and the crystals are further apart, showing as longer wavelengths of color like red and yellows.

Many chameleons don’t have the same vibrance and range of color as the more popular panther (Furcifer pardalis) and veiled chameleons (Chamaeleo calyptratus). Still, most will show a tendency for cooler blues and greens when calm, and warmer yellows reds and dark colors when agitated.

Chameleon’s color changing abilities are controlled by their level of stress or excitement so though camouflage is a byproduct, chameleons actually change color to communicate with others and adjust their body temperature.

Flamboyant Cuttlefish (Metasepia pfefferi)

Another amazing family of color changing creatures are the cephalopods! These include cuttlefish, squid, octopus etc.

They are able to change colors rapidly and some can even change their shape too. Cephalopods have stretchy sacks full of pigment, connected to muscles, that allow the animal to change color with speed and precision. When the chromatophore expands, the color shows more than when it contracts.

The muscles that control the cells are connected to the nervous system, so the cephalopod has complete control of the chromatophore’s movement. This is how it can change color so fast and accurate.

Beneath the regular yellow, brown, and red chromatophores are the iridophores.

Here is a pointillism drawing I did of a blue ringed octopus (Hapalochlaena)

In cephalopods, the Iridophores are under a layer of chromatophores, so the amount that the chromatophore expands and contracts also determines how much of the Iridophores are shown. The movement of the Iridophores, unlike the movement of the chromatophores, are not controlled by the nervous system. Recent studies have shown that they may actually be controlled by hormones of the cephalopod.

As described before, the iridophores reflect light using crystalline plates. The orientation of the crystalline plates determines the colors it will show.

You can learn more about the amazing cephalopods here: https://claralogsdon.com/cephalopods/

Sources: Smithsonian, LiveScience, Biology for Better

Filed Under: Biology, Learning Tagged With: animals changing color, chameleon changing color, chameleons, changing color, cuttlefish changing color, how do animals change color, how do chameleons change color, octopus changing color

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