When I was a kid, I didn't realize the Tasmanian devil was a real animal. I thought it was just that crazy, snarling, slobbering Looney Tunes cartoon character. I still like Taz, but it turns out there is a real Tasmanian devil, and the two don't look much like each other.
What the heck is a Tasmanian Devil?
First of all, Tasmanian devils are carnivorous marsupial mammals. Marsupials are characterized by giving birth to very underdeveloped young (often smaller than a jelly bean). The young then move into a pouch on the female's body, attach themselves to a nipple, and go through most of their development in the pouch instead of inside the mother's body. Placental mammals (including humans), on the other hand, go through extensive development inside the mother's body before being born, and they get nutrients from the mother's blood through a placenta.
Tasmanian devils are now the largest carnivorous marsupials. They've only held this title since 1936, which is when the thylacine (the Tasmanian tiger) became extinct. Tasmanian devils are about the size of a small dog, with an average weight of 18 pounds (8 kg) for males and 13 pounds (6 kg) for females.
Devils are found mainly on the Australian island state of Tasmania, although a small population has been reintroduced to mainland Australia, where devils have been extinct for hundreds of years.
Early European settlers gave this animal the name devil after seeing the creature display some of its rather bizarre behaviors when feeding and defending its food, including baring its teeth, lunging at anything that gets near, and emitting frightening screeches and growls. As you can probably guess, these behaviors are also what inspired the crazy Looney Tunes character.
Amazing Facts about Tasmanian Devils
First, let's consider this animal's reputation for being insanely aggressive. Is this reputation deserved? Yes and no. Yes, they fiercely defend themselves when attacked, but so do many other animals. They open their mouths wide, baring their teeth, but this is usually just a threatening gesture.
Devils are typically solitary, but the smell of a dead animal carcass will bring them together to feed. One of the rituals of this type of feeding is that they aggressively jockey for a good feeding position on the carcass. It's important to point out that many of their aggressive feeding behaviors do not actually involve physical harm. Studies have found that they use twenty different aggressive postures and eleven different aggressive sounds to intimidate each other without actually fighting. Their famous open-mouth yawn is an example of an aggressive gesture. Sometimes they stand on their hind legs and "spar," shoving each other with their front paws and their snouts.
That being said, the posturing and sparring doesn't always work, and devils do resort to vicious fighting. Scars from these fights are commonly seen on their faces and rumps, particularly in the males, who also fight during the breeding season.
Check out this video on the devil's aggressive behavior.
Tasmanian devils can bite really hard. Due to the arrangement of skull bones and jaw muscles, devils have a bone-crushing bite. In fact, they have one of the strongest bites (per unit of body mass) of any mammal. Their heads and necks are proportionally large compared to their body size. These strong jaws allow them to eat the entire bodies of their prey (and carrion), including the bones. In fact, devils have teeth that are adapted to feeding on bones. They have the same number of teeth as dogs, but unlike dogs their teeth grow continuously throughout their lives, which is important if you are constantly chewing on things as hard as bones.
Speaking of eating, Tasmanian devils are predators, but they are also opportunistic, and they actually feed on carrion (which they find with a keen sense of smell) more often than they feed on animals they kill. When hunting, one of the devils' favorite prey is the wombat, which is relatively easy to kill. They also hunt small wallabies and other smallish marsupials, as well as birds, reptiles, frogs, fish, and domestic farm animals. They will eat just about any dead animal they find, including fish washed ashore and roadkill. They have even been known to dig up dead animals that people have buried. They were seen excavating a horse that had died of disease and had been buried.
When Tasmanian devils find or kill a meal, they really take advantage of the available food. They gorge themselves, sometimes eating as much as 40% of their body weight in one day! When food is abundant, they are able to store fat in their tail. In fact, a good sign of a healthy devil is a nice, plump tail.
Um, this may seem a bit disturbing, but Tasmanian devils have a habit of falling asleep inside the carcasses of large carrion animals. This allows them to defend the carcass from other scavengers, and it's also a matter of convenience—they can start eating again immediately after waking up.
Tasmanian devils are athletic. They are excellent tree climbers and swimmers, as well as long-distance runners. A devil can maintain a pace of 15 miles per hour (24 km/hr) for an hour straight.
When it comes to mating season, you probably won't be surprised that male devils fight aggressively over females (I guess fighting is just a way of life for these pugnacious critters). The females then mate with the winning males. Sometimes the pair will mate off and on for up to eight days, and the male sticks around to guard the female, preventing other males from mating with her.
Females give birth standing up, which is not a problem, considering each baby isn't much bigger than a grain of rice (remember, that's how marsupials do things... the babies develop outside the body instead of inside). Here's where things get a little weird. The female gives birth to 20 to 30 tiny young, and the babies have to race to the pouch. Why? There are only FOUR nipples in the pouch. That means most of the young will not survive, so getting to one of the four nipples quickly is literally a matter of life and death.
The surviving young develop inside the pouch for about three months. After the mother kicks them out, they continue living in the underground den for another three months before going out on their own. Baby devils are called joeys, pups, or imps.
So, the Tasmanian Devil deserves a place in the S.A.H.O.F.
(Slick Animal Hall of Fame).
FUN FACT: The word slick has a long and diverse history, with numerous meanings. It may have originated in about 900 A.D. from the Norwegian word slikja, which was a verb meaning "to make something smooth," like making a rough piece of wood smooth. Starting in the 1620s, the word slick was used as a noun for a type of cosmetic. Then starting in 1849 it was used as a noun for a smooth surface of the water caused by spilled oil (an oil slick). Of course, here we are using it as an adjective. Starting in the 1590s, it was used as an adjective to describe someone who is "clever in deception." Finally, in 1833, it became a slang adjective meaning "wonderful, first-rate, excellent." Example: "The new Rampage Ridge is one slick thriller."
So, slick is another way to say awesome!
- Looney Tunes Tasmanian Devil - Wikimedia Commons
- Tasmanian devil 3D rendering on white background - DepositPhotos
- Tasmanian devil with its mouth open - DepositPhotos
- Two Tasmanian devils fighting - DepositPhotos
- Tasmanian devil, fat and lounging on the ground - DepositPhotos
- Tasmanian devil running, on white background - DepositPhotos
- Two baby Tasmanian devils handled by zoo employee - DepositPhotos
A number of different animals have been given Christmas-themed names. For example, the candy cane shrimp. Although not an animal, there is the common house plant called the Christmas cactus. Christmas Island, an Australian territory in the Indian Ocean, has several animals with Christmas names, such as the Christmas imperial pigeon, the Christmas frigatebird, and my favorite, the Christmas boobook (sometimes called the Christmas hawk-owl).
The Christmas tree worm got its name because it has two "crowns" that stick up, looking very much like two tiny Christmas trees.
What the heck is a Christmas Tree Worm?
Christmas tree worms (Spirobranchus giganteus) are marine worms that live on coral reefs in tropical areas around the world. They are polychaetes, which are segmented, burrowing worms. They attach themselves to the coral then grow a hard, calcium carbonate tube around their body for protection. The tube attaches to the coral. and the coral often grows around the tube. The worm never leaves that spot for the rest of its life.
Their flowery crowns come in a variety of colors, and the worm's body is only about 1.5 inches (3.8 cm) long. Although they are small, these worms are easily spotted when they have their crowns protruding from their coral burrow.
Check out the variety of colors below.
Amazing Facts about Christmas Tree Worms
First, let's talk about those beautiful Christmas tree structures. Maybe it's just me, but these structures look like something from a Dr. Seuss picture book. But what are they? The two crowns are highly specialized mouthparts called palps. They help with feeding and with getting oxygen from the water. Each of those spiral appendages is covered with feathery tentacles. The tentacles have numerous, tiny, movable, finger-like structures called cilia. When planktonic prey animals get caught in the tentacles, these cilia move the prey down into the worm's mouth.
Although the Christmas tree crowns are mainly used to capture prey, they also help the worm breathe. Therefore, the crowns are often called gills, but that's not really a correct name.
When threatened, Christmas tree worms can pull these crowns into their burrow really fast, within just a few milliseconds. Once their feathery plumes are pulled inside their tube burrow, they move another modified mouthpart called an operculum into place over the opening. The operculum is hard and serves as a protective hatch, making the worm safe in its burrow.
Check out this beautiful video showing numerous Christmas tree worms emerging from their tubes. If you watch closely you can see the operculum moving aside as they emerge.
Amazingly, Christmas tree worms can live for 40 years or more, particularly in pristine, unpolluted coral reefs.
Let's consider how these worms reproduce. Keep in mind that they stay in their tube their entire adult life, so they cannot crawl around to find mates. Because they're anchored to one spot, they've developed a specialized way to sexually reproduce. The females simply release unfertilized eggs into the water, and the males release sperm into the water. The water currents carry the eggs and sperm away. If the worms are lucky, some of the sperm will meet some of the eggs. This method of reproduction is called broadcast spawning.
Once an egg is fertilized, it becomes a larva very quickly, within 24 hours. The larvae drift around with all the other plankton for 9 to 12 days as they grow. When it's time to settle down, they attach to a coral rock and start growing their hard calcium carbonate tube, in which they will live out their life, eventually starting the life cycle all over again be releasing eggs or sperm into the water.
Although the worm itself is only 1.5 inches (3.8 cm) long, the tube it constructs is often 8 to 10 inches (20 to 25 cm) long. So, even though they stay inside their tube, I guess they have at least a little room to move around.
The most common predators of Christmas tree worms are shrimp, crabs, and sea urchins. Some fish also feed on them. Usually, though, these predators only bite off the tree-like crowns. When that happens, the worms can regrow their crowns in a few weeks. Christmas tree worms are often collected by humans because their bright colors make them desirable to aquarium enthusiasts. That's a relatively minor threat to the population, though. Not surprisingly, the biggest threat to these worms is the destruction of coral reefs due to pollution and climate change.
So, the Christmas Tree Worm deserves a place in the P.A.H.O.F.
(Posh Animal Hall of Fame).
FUN FACT: The origins of the word posh are somewhat uncertain. Some sources claim it is an acronym for port outward, starboard home, which was used to describe the shipboard accommodations of wealthy Victorians traveling aboard P & O Lines to India and back (to keep their cabins out of the sun). However, there isn't much evidence of this. More likely, the word came from the slang posh, which was used among thieves to describe a "dandy" with money (a good target for theft). Anyway, particularly in the UK, the word came to mean "smart, elegant, or fashionable." Considering the beautiful appearance of the Christmas tree worm's crowns, I think this word fits nicely.
So, posh is another way to say awesome!
- Christmas tree worm #1, orange crowns - DepositPhotos
- Christmas tree worm #2, yellow crowns - DepositPhotos
- Variety of Christmas tree worms on coral - Nhobgood Nick Hobgood, CC BY-SA 3.0, via Wikimedia Commons
- Christmas tree worm #3, blue crowns - Betty Wills, CC BY-SA 4.0, via Wikimedia Commons
- Christmas tree worm #4, red and white crowns - DepositPhotos
Turtles are strange reptiles with ribs that are modified and fused to their backbone to form a hard external shell across their back. Turtles can pull their head inside of their shell, and turtles as a group can be divided into two subgroups based on how they pull their head into their shell. Most turtles and tortoises pull their head straight back into the shell. However, there is a group of turtles, called the Pleurodira (the side-neck turtles), that pull their head into the shell sideways.
Because they pull their head in sideways, this allows these turtles to have longer necks. The photo below, of a Siebenrock's snake-neck turtle, shows how this works. By folding the neck to the side, there is room for a lot more neck!
What the heck is a Snake-neck Turtle?
The snake-neck turtles (family Chelidae) are one of the groups of side-neck turtles, distinguished by their unusually long necks. These turtles are restricted to the southern hemisphere, found in Australia, New Guinea, Indonesia, and South America.
Snake-neck turtles live mostly in water, and they can stay submerged for long periods of time. They are predators, and the long neck helps them grab prey animals with their mouth.
Often, the neck on these turtles can be as long as the turtle's shell.
Amazing Facts about Snake-neck Turtles
First we need to talk about that long neck. When grabbing fish, snails, crustaceans, tadpoles, insects, and various other invertebrates, this neck makes it easier for the turtle to reach out and quickly snap up a meal. They use a feeding strategy called strike-and-gape. When their nose gets close to their prey, they open their mouth quickly and lower their hyoid bone. This creates a vacuum inside their throat, which sucks in water, along with the prey animal.
Check out this video on snake-neck turtles.
These turtles spend a lot of time resting on the bottom of streams, rivers, and swamps, and this long neck also serves as a snorkel. Without having to swim anywhere, the turtle can extend its neck to the surface every now and then when it needs to take a breath.
They also spend a lot of time basking in the sun to warm up their body and speed up digestion.
Let's take a closer look at the two main groups of turtles, the side-neck turtles (Pleurodira), and the "hidden-neck" turtles (Cryptodira). As I stated above, the most obvious difference between these two groups is the anatomy of the neck. Hidden-neck turtles retract their neck into their shell by bending their neck into an S-shape vertically (it looks like an S from the side). Side-neck turtles bend their neck in a S-shape horizontally (looks like an S from directly above or below). This may sound like an insignificant difference (like the stars on the Sneetches in the Dr. Seuss book). However, this difference is only one indicator of anatomical differences that have distinguished the two groups of turtles since the early Jurassic, 200 million years ago. That's how long the two groups have been separated evolutionarily. In other words, they are not closely related at all.
There are about 360 living species of turtles in the world today, but only 65 of those are side-neck turtles. The others are hidden-neck turtles. Only 16 of the side-neck turtle species are specifically considered snake-neck turtles, characterized by exceptionally long necks.
An example is the broad-shelled snake-neck turtle pictured below.
Snake-neck turtles are polygynandrous, which means both the females and the males often have multiple mating partners each mating season. Therefore, during the mating season, males are extremely active, moving as much as possible in their attempt to increase their chances of finding multiple mates.
The males have an elaborate courtship, in which they bob their head up and down. If they successfully impress a female, mating takes place in the water.
When females are ready to lay their eggs, they locate a suitable spot where they can dig a hole near the water, lay their eggs in the hole, then cover it back up. They lay 8 to 24 eggs, depending on the species and on environmental conditions. After an incubation period of up to 150 days, the young hatch, dig their way to the surface, and head for the water as quickly as possible. The young are vulnerable to predators, and many do not make it to adulthood. Those that do survive often live over thirty years in the wild, and even longer in captivity.
Below is a hatchling snake-neck turtle.
So, the Snake-neck Turtle deserves a place in the F.A.H.O.F.
(Frontline Animal Hall of Fame).
FUN FACT: The word frontline (or front-line) is an adjective that evolved from the two-word noun phrase front line, which, in a military sense, refers to the forefront of a battle or military conflict. Eventually, the words were combined to create an adjective with several meanings. The first meaning is related to the military sense of the phrase front line, meaning "located or designed to be used at a military front line" (example: A frontline ambulance helicopter). The second meaning is more broad, related to "the forefront in any action, activity, or field" (example: a frontline health worker in the pandemic). A third meaning is related to proficiency, something or someone that is cutting edge or at the forefront (example: if I'm having brain surgery, I want it done at a frontline hospital).
So, at least in this third sense, frontline is another way to say awesome! Well, kind of.
- Jumping kangaroo - DepositPhotos
- Sidewinder - "Sidewinder With its Head in the Air" by Michael R Perry is licensed under CC BY 2.0
- Dung beetle - DepositPhotos
- Komodo dragon - DepositPhotos
- Siebenrock's snake-neck turtle on white background - DepositPhotos
- Snake-neck turtle, on rock with black background - DepositPhotos
- Snake-neck turtle basking on a log - DepositPhotos
- Broad-shelled snake-neck turtle - Sam Fraser-Smith, CC BY 2.0, via Wikimedia Commons
- Hatchling snake-neck turtle - Tortoise Town
Mimicry in nature has always fascinated me. Viceroy butterflies look like monarch butterflies (to avoid being eaten... monarchs are toxic). Geckos that look like leaves (camouflage). Milk snakes (harmless) that look like coral snakes (venomous). Alligator snapping turtles that have a tongue that looks like a wriggling worm (to attract prey fish).
The list of examples could go on forever, and all of them are fascinating.
The other day I saw a photo of an atlas moth, and I decided I had to write about it. Not only is this moth impressive for its size, it's one of my new favorite mimicry examples.
What do you see when you look at the wing tips of this atlas moth?
It's almost unmistakable, isn't it? Each wing tip has a remarkable resemblance to the head of a snake. More specifically, to the head of a cobra, a venomous snake. The resemblance is so striking that the moth's Cantonese name is translated as snake's head moth.
Let's explore this awesome animal further.
What the heck is an Atlas Moth?
The atlas moth is one of the biggest insects in the world, with a wingspan of 10.6 inches (27 cm). And the caterpillars are ginormous too, at 4.7 inches (12 cm) in length.
These moths live in tropical forests in Asia, including China, India, Malaysia, and Indonesia. They may have been named after Atlas, the titan god of Greek mythology, but some people believe the name may have come from the way the moth's wings resemble a map.
Atlas moth caterpillars are voracious eaters and feed on leaves. Once they metamorphose into adults, however, they don't eat anything at all. In fact, the adults don't even have mouths!
Amazing Facts about the Atlas Moth
First I want to talk about those cobra images on the atlas moth's wings. To me, it seems quite obvious that this is a wonderful example of Batesian mimicry. This is a category of mimicry in which a harmless mimic resembles a plant or animal that is harmful. The atlas moth is harmless, but it resembles a harmful snake, thus frightening off potential predators.
This is also known as a diematic pattern (when a coloration pattern has the result of startling or frightening potential predators).
I should point out that some entomologists are not convinced that the atlas moth is mimicking a snake. What?! Are they crazy? Like I said, the mimicry seems obvious to me. Besides the clear resemblance to a cobra's head, I have a few additional arguments to prove it.
Argument #1: Batesian mimicry can only evolve if the harmless animal lives in the same geographic area as the harmful animal it mimics—at least at some point in the past. Here in Missouri, we have harmless milk snakes, but we do not have venomous coral snakes. However, when milk snakes evolved a color pattern that resembles a coral snake, the two types would have had to live in the same area, where predators instinctually avoided coral snakes. Coral snakes live in the US, so I am assuming milk snakes gradually expanded their range beyond the range of coral snakes after they evolved this color pattern. The same circumstances would have to be true for atlas moths and cobras. And, in fact, cobras do live in much of the same range as the moths.
Argument #2: The cobra pattern on atlas moth wings would only work on predators that rely primarily on vision to hunt. As it turns out, the moth's main predators, birds and lizards, are visual predators.
Argument #3: When an atlas moth is threatened, it spreads its wings and moves slowly (and sometimes shakes them), which tends to make the wing tips look even more like two live cobras.
Check out this brief video.
Are you convinced that the atlas moth's resemblance to cobra heads is mimicry? Or do you think it's a coincidence?
Astoundingly, some of the moths have variations in the cobra-head pattern. Look at the example below... this pattern not only makes it look like you are looking at the cobra head from above, it also has white touches that make it look like it is glossy and reflecting the light!
Let's take a look at atlas moth reproduction and life cycle. Females lay a cluster of about 150 round eggs, sticking them to the underside of a leaf. After about two weeks, tiny green caterpillars hatch out. They don't stay tiny for long. After eating their own eggshell, they get to work chomping on leaves, eventually growing to 4.5 inches (12 cm) long and 1 inch (2.5 cm) thick. It takes them about 100 days to grow that large.
When full grown, the caterpillar will spin a silk cocoon (pupa) attached to a twig. After four weeks in the cocoon, an adult moth emerges.
Adult atlas moths are weak, shaky fliers, so they rest during the day. At this point in their lives, they only have one purpose, to find a mate, which they do at night. The adults do not have a mouth and do not eat at all, which means they have to find a mate within a week or two, before they use up their fat reserves and die.
The female moth releases a potent chemical to attract males, and males are really good at detecting this chemical—they can detect only a few molecules from several miles away, then they follow the scent gradient until they find the female.
Check out this video about the atlas moth life cycle.
One last tidbit of information. Because atlas moth larvae are so big, and because they spin silk to create their cocoon, people in some countries use the vacated cocoons as purses. The cocoon, which is extremely strong, is just the right size for a small change purse. All you need to do is sew on a zipper!
So, the Atlas Moth deserves a place in the S.A.H.O.F.
(Superb Animal Hall of Fame).
FUN FACT: The word superb originated in the 1540s, and it meant "noble, magnificent." It came from the Latin superbus, which had more diverse meanings, including "grand, proud, splendid; or haughty, vain, insolent." By 1729, superb was (and still is) primarily used to mean "very fine." So, superb is "an adjective of praise for that which is exceptional." Surprisingly, the word superb did not originate by simply adding a b to the end of the word super. Super is a Latin preposition that means "above." Superb, on the other hand, is actually a shortened form of the Latin superbus.
So, superb is another way to say awesome!
Years ago Trish and I were in Boston, and we had a chance to go on a whale-watching boat tour for a few hours. We did indeed see a few whales, but for some reason, I was most excited when a massive whale shark swam right beneath us as we peered over the side of the boat.
Whale sharks are the largest living fish. They are also the largest non-mammal vertebrate animal. How large are they? The biggest individual found was almost 19 meters (62 feet) long! If you're wondering about how much these fish weigh, well, very few of the really large ones have been weighed. However, one whale shark that was 39 feet (12 m) long weighed about 33,000 pounds (15,000 kg).
It's time we take a closer look at this gentle giant.
What the heck is a Whale Shark?
First of all, whale sharks (Rhincodon typus) are not whales, they are sharks. As you probably know, whales are mammals (as are humans). Sharks, on the other hand, are fish.
Just because whale sharks are sharks and are huge, that doesn't mean they are dangerous to people. Whale sharks are filter feeders--they filter plankton and small fish from the water. They do not attack and kill large prey. The whale shark is one of only three filter-feeding sharks—the other two are the basking shark and the megamouth shark.
Amazing Facts about Whale Sharks
Let's talk about this unusual filter-feeding habit. Whale sharks cruise along, mile after mile, swimming close to the surface, scooping up plankton in their huge mouths. Most sharks have a mouth that is located under their head, but a whale shark's mouth is situated right up front, to help scoop up all those yummy little plankton animals.
Look at the size of that mouth! When measured, one whale shark that was 40 feet (12 m) long, had a mouth that was 5.1 feet (1.5 m) across. That's one big mouth!
Although they are too small to see in the above photo, whale sharks have about 300 rows of teeny, tiny teeth. Below is a photo of a section of these teeth. Strangely, these teeth have nothing to do with feeding. In fact, they serve little (if any) purpose at all and are therefore considered to be vestigial teeth. The word vestigial refers to body structures that used to be larger and more functional but are in the process of going away over time due to evolution. An example of vestigial structures in humans are the muscles attached to our ears that used to allow our distant ancestors to move their ears, like many other animals can.
So, if these thousands of teeth aren't used, how does a whale shark actually eat? As stated above, they cruise around, scooping up plankton. Sometimes they also actively open and close the mouth, sucking in water. With either method, a large quantity of water rushes into the mouth and is then expelled through the gills. So, what keeps all those yummy plankton animals from getting expelled along with the water? Well, situated on their gills, whale sharks have twenty comb-like structures called filter pads. As the water is expelled through the gills, the plankton and tiny fish get caught in these filter pads. Whenever the filter pads get full, the whale shark swallows all that stuff, making room for more.
Remember that huge mouth? It's easily big enough for a human to swim into (or get sucked into). But even if that happened, the whale shark could not swallow a person because their throats are too narrow to swallow anything bigger than your fist. If you somehow accidentally got sucked into a whale shark's mouth, the shark would probably simply "cough" you back out. Whale sharks are often observed coughing out excess particles that they don't want to eat.
Check out this video about whale sharks.
Whale sharks are known to be very docile toward divers, often even allowing divers to grab hold and go for a ride. However, disturbing these magnificent fish in such a way is discouraged by biologists because it puts excess stress on the sharks. But observing them respectfully, even up close, is safe for both the diver and the fish. In fact, divers travel to various sites around the world just for the opportunity to see these creatures.
The whale shark's huge size requires that it find areas with abundant food. These fish are notorious for incredibly long migrations (thousands of miles), in which they arrive at their destination just at the right time for an annual explosion of certain types of plankton. Keep in mind that whale sharks are slow swimmers, moving at only about three miles (4.8 km) per hour. So, such migrations take a looong time!
Whale sharks are usually solitary, but sometimes they are seen swimming in groups of hundreds.
Whale sharks grow really old. Although studying their age is difficult, scientists estimate that whale sharks live between 60 and 100 years, and some experts suggest that they can live up to 150 years.
Because whale sharks are so difficult to study, they have never been observed giving birth. And mating has only been observed twice (from an airplane). However, we can deduce some information on their reproduction from other observations. Based on dissection of female whale sharks, we know these fish are ovoviviparous (have fun pronouncing that one). Ovoviviparous refers to a form of reproduction that is halfway between egg-laying (oviparous) and live birth (viviparous). Ovoviviparous animals have young that develop inside eggs, but the eggs stay inside the female's body until they hatch, and then the live young are born. Cool, huh?
Here's where things get a little confusing. Female whale sharks can have a lot of fertilized eggs in their body at once. One female that was captured in 1996 contained about 300 shark pups. However, the females do not give birth to all these pups at once. Instead, they keep the sperm from one mating inside their body, and they give birth to only a few pups at a time. Apparently they can continue regularly producing pups like this for a long period of time.
Below is the smallest whale shark pup ever found, which implies that this is about the size of newborn pups. This individual was found tied to a stake on a beach in the Philippines (notice the red string tied to its tail). No one knows why it was tied there, or where it came from, but it was measured and released safely into the wild. Because this is the smallest pup ever observed, we assume this is the size of newborn pups. We assume newborn pups are about 18 inches (46 cm) when they are born.
I suppose because I have so many grandkids, I cannot read the phrase "baby shark" without an incredibly annoying song running through my mind endlessly.
Baby shark, doo, doo, doo, doo, doo, doo...
If you don't know what I'm talking about, you're lucky.
So, the Whale Shark deserves a place in the S.A.H.O.F.
(Sublime Animal Hall of Fame).
FUN FACT: Depending on the source, the word sublime originated in the late 1400s or the 1500s. It came from the Latin sublimis, which means "uplifted, high, borne aloft, lofty, exalted, eminent, or distinguished." Today the word sublime has a variety of different meanings. In chemistry, it is a verb meaning "to convert (a solid substance) by heat into a vapor." It also has several uses as an adjective. For example, it can mean "elevated or lofty in thought or language" (example: Stan's novels are sublime literature). It can also mean "impressing the mind with a sense of grandeur" (example: The changing leaves in the fall provides sublime scenery). For our purposes today, though, I am relying on the definition "supreme or outstanding" (example: The whale shark is a sublime fish).
So, sublime is another way to say awesome!
- Whale shark #1, next to swimming diver - DepositPhotos
- Whale shark #2, closeup of mouth - DepositPhotos
- Section of whale shark teeth - D Ross Robertson, Public domain, via Wikimedia Commons
- Whale shark #3, swimming near surface against dark background - DepositPhotos
- Baby whale shark - Aquaworld
Due to the Halloween season, I'm going with a rather creepy-themed Awesome Animal today. I present to you the hammerhead worm—the coolest worm most people have never heard of.
There's even a species with Halloween colors (see image below).
Honestly, I didn't know anything about these until recently, and I immediately decided I needed to feature them as an Awesome Animal.
What the heck is a Hammerhead Worm?
Actually, these are not worms like earthworms. Earthworms are segmented worms. Hammerhead worms, on the other hand, are planarians, a type of flatworm. Sometimes they are called broadhead planarians. Another common name--landchovy.
Most species of planarians live in freshwater or saltwater, but some types, like the hammerhead worms, live on land.
Perhaps the most distinguishing characteristic is the broad, shovel-shaped head.
Land planarians have what's called a creeping sole that allows them to move around. This creeping sole is on their ventral (belly) side, and it has a thick layer of cilia (moving, hairlike projections) that beat back and forth on a strip of mucus the worm lays down as it progresses forward.
What, you didn't expect these things to produce copious amounts of slime?
To top it all off, these worms are fierce predators, as well as cannibalistic. Oh, and they are invading North America, Europe, and many other parts of the world.
And... if you cut them into pieces, you end up with more hammerhead worms.
Oh... and some of them grow to 18 inches (half a meter) long.
Amazing Facts about Hammerhead Worms
Wait... what was that statement about cutting them up and ending up with more? Planarians are famously good at regeneration. You can literally slice one in half, either lengthwise or across its body, and in two to three weeks each half will grow a new planarian. If you cut one into five pieces, you might get five worms (this depends on several things, including how big the pieces are).
In fact, this splitting is the main way most hammerhead worms reproduce. Yeah, they are capable of sexual reproduction—you know, with a male and female—BUT, hammerhead worms are hermaphroditic, which means each individual has both male and female sexual organs. Therefore, any individual can mate with any other individual. Strangely, though, they usually don't. Instead, they seem to prefer to make new hammerhead worms by splitting their body apart. This is known as fragmentation and is a handy form of asexual reproduction.
How do they split themselves apart? Well, they stick the tail end part of their body to the ground (remember all that slimy mucus?), then they keep moving forward (remember that creeping sole?) until their body tears right in half. The broken piece they leave behind becomes a younger worm, growing longer and developing a broad hammer head in a few weeks. A hammerhead worm can break apart like this one or two times per month.
Lifespan of a hammerhead worm: Potentially immortal.
I know, that's weird, but get this—hammerhead worms have no respiratory system, no circulatory system, no skeleton, and their mouth is also their anus.
Let's consider those one at a time.
No respiratory system: There's no need. Oxygen enters and carbon dioxide leaves the worm's body by diffusing directly through the body wall.
No circulatory system: There's no need, for the exact same reason as above.
Mouth is also the anus: Now we're talking about the digestive system. It's a simple system. The mouth is located in the center of the ventral (belly) side. Food is taken in there and travels through a pharynx to a gastrovascular cavity, where it is digested, and because this cavity branches out to various parts of the body, that's how the nutrients get everywhere they need to be. Whatever is left over gets spit right back out the mouth. Nice.
Let's talk about how these creatures eat. As I stated above, they are predators. Unfortunately, many of them kill and eat earthworms. In case you didn't know, when it comes to almost every aspect of an ecosystem, earthworms are the good guys. gardeners know you can't have healthy soil without earthworms. That's why invading hammerhead worms could be bad news.
Hammerhead worms are vicious earthworm hunters. They glide around on the ground with their spade-like head held up, moving it back and forth like a radar. The broad head has special chemoreceptors that detect earthworm mucus. When they catch up to one, they subdue it with a coat of their own mucus (wow, there's a lot of mucus in this newsletter), then they tear it up into pieces. The hammerhead worm then extends its pharynx out of its mouth and secretes earthworm-dissolving enzymes all over the chopped-up prey. After the earthworm becomes soup, the predator sucks it all up, digests most of it, and spits the remains back out the mouth.
These creatures are an earthworm's worst nightmare (although it seems unlikely earthworms have nightmares—they have very primitive brains).
Hammerhead worms are also enthusiastically cannibalistic. They like eating each other.
Hammerhead worms are native to Asia and Australasia. However, as I stated above, they are becoming invasive worldwide, probably due to being transported on horticultural plants.
Possible solution: Maybe predators (or even people) could eat them. Nope. Many earthworms are edible, but these creatures are toxic. They contain a potent neurotoxin called tetrodotoxin, which is also found in some newts, pufferfish, and the blue-ringed octopus. Other than each other, they have few predators.
If you pick them up, their surface mucus can cause skin irritation. And, of course, don't even try chopping them up.
I know... I'm kind of making these creatures out to be overly creepy for this Halloween edition. But keep in mind that in their native habitats, hammerhead worms are important to the ecosystem and should not be killed. They are, after all, awesome animals.
When it comes to invasive hammerhead worms, they could become a problem. If you see an invasive hammerhead worm, you can pick it up with gloves or tweezers and put it in alcohol, or salt, or a sealed container. It might also help to report it to local authorities, who might be tracking sightings in your area.
So, the Hammerhead Worm deserves a place in the E.A.H.O.F.
(Elegant Animal Hall of Fame).
FUN FACT: The word elegant (meaning "tastefully ornate") originated in the late 1400s, and it came from the Old French élégant. Another definition, one that I think applies to the appearance of some of the hammerhead worms, is "graceful in form or movement." Yet another definition is "excellent; fine; superior," as in "This is an elegant wine." I suppose you could consider hammerhead worms to be nothing more than slimy, slug-like things, but you have to admit they have a rather delicate and graceful appearance, right?
So, elegant is another way to say awesome!
- Hammerhead worm from Borneo, orange, black, and white - DepositPhotos
- Hammerhead worm, black and white - DepositPhotos
- Hammerhead worm, black and orange #2 - Bernard DUPONT, Flickr, Creative Commons License (CC BY-SA 2.0)
- Hammerhead worm, long, thin, black - "Hammerhead worm - Carita - West Java_IMG_2708" by fveronesi1 is licensed under CC BY-SA 2.0
- Hammerhead worm head, brown and white - DepositPhotos
I like living in North America, but I've always felt that we are sadly deprived of the splendor of marsupial mammals. I mean, really, we only have ONE marsupial, the Virginia opossum. It's an interesting animal, but come on—only one? Australia is a true wonderland of marsupials. There are about 330 species of marsupials in the world, and Australia has two-thirds of those, about 250. Actually, South America has about 120 marsupial species, which is impressive also, especially compared to our ONE!
Okay, I'm finished with that rant.
Today's Awesome Animal is, not surprisingly, a marsupial mammal. It has the delightful name of Numbat. Actually, I don't know why I think this name is delightful. I just like the way it rolls off the tongue... numbat.
What the heck is a Numbat?
The numbat is not closely related to any of the other living species of marsupial, and it's the only member of its family, Myrmecobiidae (don't blow a fuse trying to pronounce that one). Genetic studies show that the numbat diverged from other marsupials about 37 million years ago. So, it really is unique.
Numbats used to be common over a large area of southern Australia, but (big surprise!), they have been greatly reduced since Europeans arrived there. Now they are endangered and live in only two relatively small areas. This is believed to have been caused almost entirely by the intentional introduction of the European red fox in the 1800s.
Numbats are fairly small, at 14 to 18 inches (35 to 45 cm) in length, including the tail.
They are unusual in that their diet consists almost entirely of termites. In fact, they are highly specialized termite eaters. See the numbat's termite-slurping utensil (otherwise known as its tongue) below.
Amazing Facts about the Numbat
First let's consider what it means to be a marsupial mammal, especially since I made such a fuss about it above. Primates (including humans), rodents, dogs, cats, and many others are called placental mammals. They are called this because of the presence of a placenta, a specialized vascular organ that develops during gestation of the young. The placenta allows the mother to "feed" the fetus and remove waste from the fetus while the fetus is inside the womb. This last part is important because the fetus is much safer inside the womb than outside. It also means baby placental mammals develop to a large size inside the womb, which means giving birth is a rather stressful event for the female.
Placental mammals include all mammals except for marsupials and monotremes. The first placental mammals evolved about 160 million years ago.
How is a marsupial different? Well, many marsupials have a rudimentary placenta, but it is much less efficient than a true placenta. This limits how long the fetus can remain in the womb. So, the babies come out of the womb (they are born) at an early stage of development. For example, a kangaroo baby is born when it is only the size of a jelly bean.
These extremely small young usually have tiny hands that allow them to make their way from the birth canal to an external pouch (called a marsupium). The baby latches its mouth onto a nipple in the marsupium and remains attached to it. There, inside the pouch, the young completes its development by taking in nutrients through the nipple (instead of through a placenta inside the womb).
Imagine this... if humans were marsupials, babies would be born when they are smaller than your thumb. So, no need for all that hassle of going through labor and a stressful birth. The baby then would crawl from the birth canal to the woman's pouch, which would be located about where her belly button would be. Marsupials, of course, do not have a belly button because a belly button is where the placenta was attached. Instead of having breasts on her chest, the mother would have nipples inside the pouch. The baby would then grow inside the pouch until it weighs about seven pounds, at which point the mother would get tired of carrying it around and would ban it from the pouch forever.
Hmm... now I can't get that series of images out of my head. But I digress...
So, numbats are marsupials. However, numbats are among the few marsupials that do not have a pouch. As mating season (December-January) approaches, the males secrete a smelly, red substance from their chest. They rub this stuff all over everything they can find, which is their way of advertising to females that they are looking for mates.
Females give birth to four babies only 14 days after mating (remember, a short gestation is standard for marsupials). The tiny young crawl to the nipples and attach. Remember, numbat nipples are not in a pouch, but the mother does have some small flaps of skin that cover the babies somewhat while they are really small. The babies remain physically attached to the nipples for at least six months, until they are so big that the mother can no longer walk around properly. Then she pulls them loose and deposits them into a nest in a burrow, returning often to continue nursing them. At about nine months, they start wandering out of the burrow.
Below is a young numbat.
Now let's talk about the numbat's diet of termites. Again, this is all they eat—nothing but termites.
When baby numbats are born, their snouts are blunt and pig-like, which helps them attach to the nipple. After they detach from the nipple, though, the snout grows longer so that it can be used to get into small holes in the ground and cavities in logs, where they use their long, sticky tongue to slurp up termites. In fact, they consume as many as 20,000 termites every day! They don't drink water at all because they get all the water they need from the termites they eat.
Because numbats only eat termites, they must live only where termites can live. If an area is too hot or cold or dry or wet for termites, numbats cannot live there. They favor eucalyptus woodlands, where there are plenty of fallen logs full of termites that are feeding on the rotting wood. The forests must be open enough for sunlight to warm up the ground and the logs, which makes the termites active. Because termites are active during the warmer daylight hours, numbats are diurnal (active during the day instead of night). During the hottest afternoon hours, numbats retreat to their burrow for a nap. Why? Because termites move deeper into logs and the ground during these hot hours. In other words, numbat habits are directly linked to termite habits.
Want to know more? Check out this video about numbats.
The below numbat is taking a break from the hard work of hunting termites.
So, the Numbat deserves a place in the W.A.H.O.F.
(Wondrous Animal Hall of Fame).
FUN FACT: The word wondrous originated in the 1400s, and it has always meant "causing wonder or amazement; very beautiful or impressive." It came from the word wonder, which originally was a noun meaning a "marvelous thing" but later became associated with the emotion one feels when witnessing such a thing. The suffix "ous" was added because it was already being used at the end of the similar word marvelous.
So, wondrous is another way to say awesome!
- Numbat #1, on a log - DepositPhotos
- Numbat #2, with protruding tongue - DepositPhotos
- Numbat #3, baby in hand - Zooborns
- Numbat #4, lounging on a log - S J Bennett from Australia, CC BY 2.0, via Wikimedia Commons
I hope you don't mind, but I'm continuing this weird theme of featuring venomous animals. After all, being venomous is a rather fascinating adaptation for survival, don't you think?
Did you know there are venomous fish? This is not to be confused with poisonous fish. Poisonous and venomous are not the same thing. Poison is a toxin that gets into the body by eating it, inhaling it, or absorbing it through the skin. Venom is a toxin that is injected, usually by fangs, a stinger, or some kind of barb. Very few (if any) snakes are poisonous, but some are venomous. Some plants are poisonous because they have toxins in their berries, leaves, or stems that will make you sick if you eat them. But they do not inject the toxins, so they are not venomous.
Stonefish are the most venomous fish we know of. Their venom protects them from predators, and it is injected by the sharp spines of their dorsal fin.
Masters of disguise, their bumpy skin and drab colors often make them look like an algae-covered stone.
What the heck is a Stonefish?
The stonefish include five species in the family Synanceiidae. They live mostly in coral reef waters in the Indo-Pacific (around Australia, New Guinea, Indonesia, and the Red Sea and Indian Ocean).
These fish grow up to 20 inches (50 cm) long, and they have a huge, upturned mouth. They do not have scales, but their skin often has warty bumps and protrusions and filaments that look like algae growing on a rock. Even their eyes can look like algae. And these fish can change their colors to better blend in with whatever the surroundings look like at the time.
Stonefish sit very still, often half buried in the sand, and wait for prey to wander by.
Amazing Facts about Stonefish
First, we need to talk about this fish's nasty habit of protecting itself with dangerous venom. Is it really the most venomous fish in the world? Yes, according to most sources. The venom is produced by special glands located at the base of each of the thirteen spines of the dorsal fin. The venom is conducted through ducts along each spine to the spine's sharp tip.
Typically, these spines are hidden, covered by the camouflaged skin. But when the fish is alarmed, it erects its dorsal fin. If something (like a stingray's mouth or a human's foot) puts pressure on the fish, this forces the skin back, and the needle-like spines penetrate and inject the venom. The more pressure applied to the fish, the more venom is released.
Stonefish venom is amazingly dangerous—it can even be fatal to humans if not treated properly with anti-venom. The results of a sting begin with agonizing pain and swelling, and bad stings can lead to necrosis, paralysis, and even heart failure.
Most human stings occur when swimmers accidentally step on a stonefish. Australia has the highest number of stonefish stings, with about 25 cases per year that are bad enough to administer anti-venom. Human deaths are rare, probably because of the availability of anti-venom, but numerous swimmers suffer the pain of stings that do not warrant the use of anti-venom.
Some aboriginal Australians have traditional ceremonies, called corroborees, in which they re-enact the events of one of their members stepping on a stonefish and dying from the sting. This is a traditional way of teaching their children about the dangers of this fish.
The stonefish uses its venom only as a defense, never for killing or capturing prey. I suppose that makes sense... how could a stonefish possibly jab the spines in the middle of its back into a fish it is trying to catch? Stonefish are obviously well camouflaged, but this is mainly to help them ambush prey. They still get attacked by predators, particularly sharks, stingrays, and sea snakes. That's when their venom helps protect them.
We don't know this for sure, but it is thought that sea snakes are immune to stonefish venom. Sea snake venom, however, is dangerous to stonefish, and after a sea snake bites, the stonefish becomes immobile, and the sea snake can swallow it without the fish's spines sticking up and getting in the way or causing damage.
Stonefish may spend most of their time sitting still and waiting, but when a prey fish or shrimp comes along, the attack comes really fast. They can grab and swallow the prey in as little as 0.015 second!
Check out this video about stonefish attacking prey.
Stonefish sometimes get stranded out of water, completely or partially, at low tide. This usually isn't a problem for them, though, because they can survive for up to 24 hours by absorbing oxygen through their skin. As a result, many of the human stings actually occur on the beach instead of in the water. It's easy to imagine how this could happen—among the exposed coral stones at low tide, a stonefish would be difficult to spot.
Stonefish are solitary animals, spending most of their lives alone except when it is time to mate. When a male finds a receptive female, the female releases her eggs into the water. The male then swims over the eggs and releases sperm onto them. The eggs hatch in only three days, but the young are vulnerable to predators and few of them survive.
Stonefish venom is a protein, so it breaks down when heated. If properly cooked, these fish can be eaten by people and are considered a delicacy in many parts of Asia. Actually, they are often eaten raw, although—not surprisingly—the dorsal spines are carefully removed beforehand.
So, the Stonefish deserves a place in the N.U.A.H.O.F.
(Numero Uno Animal Hall of Fame).
FUN FACT: The phrase numero uno literally means number one. The phrase was borrowed from Italian into English in the early 1970s. In Spanish, número uno means the same thing and is pronounced the same. Typically, in the English language, it has been used the same way number one is used, and is often used to refer to oneself or one's best interests, as in "He's always looking out for numero uno." It is also used to refer to someone or something that is ranked highest, as in "The Kansas City Chiefs are numero uno." Finally, the phrase is often used as an adjective to describe anything or anyone that is impressive or best at something, as in "The stonefish is the numero uno venomous fish in the world."
So, more or less, numero uno is another way to say awesome!
- Stonefish #1, gray and orange - DepositPhotos
- Stonefish #2, with purple splotches - DepositPhotos
- Stonefish #3, orange and red, with fins spread - DepositPhotos
- Stonefish #4, facing to the left - "Stonefish 33" by High Desert Rider, licensed under CC BY-NC-ND 2.0
In my previous Awesome Animal feature I talked about the solenodon, an unusual venomous mammal. Venom is extremely rare in mammals, so I thought it would be fun to look at another example, the slow loris.
Okay, that's not quite true. The real reason I wanted to feature the slow loris is that I just love the way this critter looks. Huge, round, saucer eyes. Funny hands and feet. Round faces... they are Earth's version of the Ewok, only much cuter.
What the heck is a Slow Loris?
Slow lorises are an unusual, primitive group of primates (primates is the order of mammals that includes humans, chimps, gorillas, orangutans, gibbons, new and old world monkeys, tarsiers, lemurs, and lorises). The eight species of slow loris live throughout Southeast Asia. They are nocturnal, tree-dwelling mammals that eat just about anything, including small animals, eggs, fruits, tree sap, flower nectar, and leafy vegetation.
They are generally slow-moving, but they can be fast if they want to... apparently they rarely want to. They make their way through the tropical forest canopy at a snail's pace, and like sloths, they will often become motionless for hours at a time, hanging upside down from a branch with hands and feet that seem to never get tired of holding on.
Amazing Facts about the Slow Loris
First we need to talk about why we consider these animals to be venomous. If you read my previous email about solenodons, you may remember that only a few mammals are considered venomous. There are solenodons, of course, as well as two species of shrew. Vampire bats could be considered venomous because their saliva has compounds that prevent blood from clotting. And the male platypus can inject venom with spurs on its feet.
The slow loris has a bizarre way of getting venom onto its teeth. Instead of having venom glands in their mouth, slow lorises get their venom from their armpits. When a slow loris decides it needs to be aggressive, it quickly raises its arms high, locks its hands together above its head, sticks its face into its armpit, and licks the oil-secreting venom glands located there. The venomous oil collects in the narrow grooves in the loris's teeth, which are sharp enough to slice right into bone. Then, when the creature bites, the venom is injected.
Slow loris venom isn't completely understood yet, but we do know one component is similar to the protein that is found in cat dander that triggers severe allergic reactions in many humans. But that's only one of many substances in the venom. Others are known to cause other problems, including intense pain.
Oddly, the purpose of this venom has been poorly understood until recently. It is not for subduing its prey—lorises eat mostly tree sap, vegetation, and small animals that would not need to be subdued. For some time, the leading hypothesis was that it was for defense against predators. As it turns out, this is not the case either.
For years, there has been anecdotal evidence that slow lorises were dangerous to each other. Zoo and animal rescue workers report that the most frequent cause of death among slow lorises is from biting each other. Illegal pet traders report that they routinely remove the teeth from captive lorises they intend to sell. Why? Not to protect the human handlers, but to protect the lorises from each other. Loris venom causes necrosis (death of the tissue near the bite), and bitten lorises would die or lose large portions of their skin, making them difficult to sell (yes, I agree... this illegal pet trade is terrible).
Recently, a dedicated team of researchers put radio collars on 82 Javan slow lorises and spent eight years tracking and studying them! Only one of these lorises was lost to a predator (a feral dog), but many of them suffered from severe bite wounds from other lorises.
So, what is the conclusion? Slow lorises are extremely territorial, and they use their nasty venom primarily in territorial disputes, or disputes over potential mates. Slow lorises, in other words, are constantly in conflict with each other! They are remarkably cute, but looks can be deceiving.
There are some viral videos of people "tickling" a slow loris. The creature raises its arms above its head, and the video claims the loris really likes to be tickled. Umm... no. When a slow loris raises its arms, it is frightened and being defensive!
Check out this video about the slow loris.
Oddly, slow lorises are usually reluctant to bite humans.
For hundreds of years, slow lorises have had interesting and often problematic connections with humans. One of the better stories is from Borneo. The indigenous people in Borneo believed slow lorises were gatekeepers to the heavens, and that every person had their own slow loris assigned to them, which would be waiting to great them in the afterlife. Malay people believed slow lorises were plagued by ghosts, and that was why they often covered their face and eyes with their hands.
Unfortunately, many of the other human connections are more harmful to slow lorises. They have traditionally been hunted based on various beliefs that their body parts could be used for all manner of health benefits. The body parts were thought to bring a curse to enemies if buried under a house or a road where the enemy frequents. The list goes on and on... In Java, women believed if they put a slow loris skull in a jug of water, the water would make their husband more agreeable and docile (because slow lorises themselves are agreeable and docile). In Cambodia, it was thought that slow lorises had medicinal powers because they could never be killed with only one hit with a stick. Slow loris meat has long been eaten as an aphrodisiac (but only for men, not women).
In their natives ranges, slow lorises are often kept for pets (usually illegally). In Indonesia, they are thought of as a living toy for young children. As you can imagine, many of these lorises die from mistreatment. Pet sellers often remove their teeth, frequently resulting in death from bleeding. Fortunately, slow lorises are now protected from international trade, and all countries in which they live have laws to protect them from local trade (although illegal collecting still occurs).
So, the Slow Loris deserves a place in the M.A.H.O.F.
(Marvelous Animal Hall of Fame).
FUN FACT: The word marvelous originated in about 1300. It came from the Middle French merveilleus, originally meaning "causing wonder, of wonderful appearance or quality." Marvel comes from the Latin mīrābilis, meaning “to marvel or wonder at.” Adding the suffix -ous turns it into an adjective (the suffix means “possessing”). Marvelous can also mean "improbable or incredible," as in "the marvelous events of Greek myth."
So, marvelous is another way to say awesome!
Thanks to Jay Dell for suggestion this awesome animal.
When we think of venomous animals, we usually imagine venomous snakes and spiders. We don 't think of mammals. However, there are a few mammals known to be venomous. The male platypus can inject venom with spurs on its feet. Vampire bats have saliva that prevents clotting and is considered a form of venom. The slow loris has a strange combination of two venoms, one from its legs and one in its saliva, and when mixed together they become even more potent. Hedgehogs can be considered venomous because they intentionally smear toxic substances on their spines, which then get into the bodies of animals trying to attack them.
Several species of shrews are definitely venomous—when biting their prey, they can inject venom that gathers in concave pits in their incisors.
One type of rare mammal, though, has distinct channels in its teeth that deliver venom when it bites. This mammal is the solenodon.
What the heck is a Solenodon?
Among the rarest mammals in the world, solenodons are insectivorous, burrowing mammals. Although many species used to live throughout North America 30 million years ago, now only two species remain, the Cuban solenodon and the Hispaniola solenodon.
Their closest living relatives are shrews, and although solenodons kind of resemble very large shrews, they are not as closely related as you might think. In fact, these creatures diverged from other mammals (including shrews) about 73 million years ago. Think of it... these animals were around, in about the same form they are today, 7 million years before the massive, astroid-related extinction event that wiped out the dinosaurs (it happened 66 million years ago).
DNA analysis has shown that Solenodons split apart from the lineage that eventually became the hedgehogs, moles, and shrews. But that split happened a loooong time ago.
Solenodons may slightly resemble shrews in shape, but they are much larger than shrews. They typically are 11 to 13 inches (28 to 32 cm) long (not including the tail) and weigh 1.5. to 2.2 pounds (0.7 to 1 kg). The photo below of a Hispaniolan solenodon gives you an idea of their size. Solenodon venom is not lethal to humans, but notice the handler is still wearing gloves... good idea.
Amazing Facts about Solenodons
First we need to talk about that venom! Here's how it works. Solenodons have modified, enlarged salivary glands in their mandible (the lower, movable jaw bone). This saliva, which happens to also be the venom, flows through specialized grooves in the lower incisors into the solenodon's prey. So, solenodons are among the very few mammals that actually inject venom, similar to how a venomous snake injects its venom. Solenodons, however, only inject venom through their lower teeth.
Recent studies have shown that solenodon saliva (the venom) contains a set of enzymes called kallikreins. These enzymes break down certain proteins, including proteins that help maintain blood pressure. When researchers injected the saliva into mice, their blood pressure immediately dropped drastically. This might be directly fatal to the solenodon's prey, or it would at least make the prey lethargic and easier to kill.
Interestingly, some shrews also have kallikreins in their saliva, which also acts as venom. At first thought, you would assume solenodons and shrews got this similar characteristic from a shared ancestor. However, this is not the case, particularly because these groups diverged 73 million years ago. As it turns out, the two groups evolved this venom ability independently of each other... a fascinating example of convergent evolution (when different organisms develop similar traits even though they are isolated from each other).
An interesting side note on this—it's possible that solenodons do not have the opportunity to actually use their venom much anymore. Why? Because the venom is most effective on prey animals that are vertebrates, such as rodents, lizards, and birds. Unfortunately, during the last 500 years many of these prey animals have been wiped out in Cuba and Hispaniola (the island that includes Haiti and the Dominican Republic) by humans. Now solenodons are forced to mainly eat insects, which are not affected by the venom in the same way.
Sadly, solenodons are adapted to an ecosystem that no longer exists.
Check out this video about how solenodons became venomous.
Solenodons have supersnouts. Take a closer look above at the creature's nearly hairless snout. You know how some people can (kind of) wiggle their nose? Well, solenodons are really good at this. Their nose is like a highly sensitive finger they can move back and forth. Solenodons, in fact, have a ball-and-socket joint at the base of the nose, kind of like a human shoulder joint, which gives the nose even more movement.
This amazingly moveable schnoz helps the solenodon investigate small holes and narrow crevices in search of prey. Solenodons have tiny, poorly developed eyes, and they hunt mostly by smell and touch.
Solenodons smell like goats. That's right—goats. Why? Because they have special glands in their armpits and groin that secrete a substance that, well, smells like a goat. Personally, I haven't been around goats enough to know what they smell like, but apparently some people who have handled solenodons do know what goats smell like.
Solenodons are rare and difficult to find or study, so very little is known about their habits. They're nocturnal, spending the daylight hours hidden away in burrows or hollow logs.
Unfortunately, there are far fewer solenodons than there used to be. When Europeans arrived on the Caribbean islands, they introduced dogs, cats, rats, and mongooses, all of which are threats to solenodons. Human development has also greatly fragmented and reduced the habitat of these creatures.
Solenodons give birth to one or two young. If three are born, one will almost certainly die. Why? Because the mother only has two nipples (which, oddly, are situated way back near her rump). If three are born, one will become malnourished and eventually die, allowing the other two to develop normally.
One last tidbit of information... solenodons are featured on postage stamps in the Dominican Republic (the Hispaniola solenodon) and in Cuba (the Cuban solenodon).
So, the Solenodon deserves a place in the J.D.A.H.O.F.
(Jaw-dropping Animal Hall of Fame).
FUN FACT: The phrase jaw-dropping first showed up in the Oxford English Dictionary in 1900. It means "causing astonishment or surprise; amazing." This one is pretty easy to figure out, as it is simply a reference to a person’s mouth open wide in amazement or shock. Sometimes it is spelled without a hyphen (jawdropping), but the hyphenated form is most common. There is only one derived form, the adverb jaw-droppingly (as in, "The solenodon has remained unchanged for a jaw-droppingly vast amount of time—73 million years.).
So, jaw-dropping is another way to say awesome!
- Solenodon beside rock - Seb az86556, CC BY-SA 3.0, via Wikimedia Commons
- Hispaniolan solenodon held in gloved hand by man - Creative Commons - "Dominican republic-17-025-Joe with solenodon-Credit DWCT" by darwin_initiative is licensed with CC BY-NC-SA 2.0.
- Hispaniolan solenodon - Miguel Landestoy - by flickkerphotos is licensed with CC BY-NC-ND 2.0.
Everyone needs a creative outlet. That's why I write.