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Archive for the ‘Unusual fish’ Category

basking shark

This video purports to be footage of a white shark off the coast of Cornwall.

Although it is possible that a white shark could show up there, this specimen is not one.

It is a basking shark. Now, it’s very easy to mistake the two species. Indeed, Kipling’s “The White Seal” claims that Kotick survived attacks from the “basking shark.” Kipling most likely meant the white shark, but in those days, it was not uncommon for people to refer to basking sharks and white sharks as if they were the same species.

They are not. Basking sharks are similarly built, but they can get substantially larger than white sharks. In fact, it is very likely that reports of huge white sharks are actually misidentified basking sharks.

Now, how do I know this is a basking shark. Location tells me a lot. White sharks are very rare north of the Bay of Biscay. (Check out the range map) It is possible that one could make it to the coast of southern England. Location is a good hint, but it is not foolproof.

Now, it is well-known that white sharks try to avoid boats. Jaws is mostly fiction mixed in with some out of date biology. If a boat approached a white shark, it is very likely to swim quickly away. It is unlikely to stay unless some food source or potential food source was the water.

Basking sharks tend to ignore boats and lazily swim along as they filter feed. It seems to me that this is the behavior that this shark is exhibiting.

Now, behavior is also not fool-proof. Sometimes white sharks do things you don’t expect, and it would not be unreasonable for one just swim around really slowly, even if a boat approached. It is not normal behavior, but it is possible behavior.

The best way to tell that this is a basking hark is the fin is too rounded.  (Compare the fins). White sharks have a more pointed fin than basking sharks do. In fact, basking sharks have very rounded fins compared to other shark species.

So Britain doesn’t have its first killer shark after all. It’s just another basking shark.

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European eel

One of the most interesting theories postulated by The Centre for Fortean Zoology is the hypothesis that many lake monster sightings are overgrown eels. Now, this theory was lampooned on Penn & Teller’s Bullshit, and in the youtube upload of the Centre’s documentary Eel or No Eel, the comments are mostly negative. How could there be a giant eel any European lake?

The theory goes that some eels are sterile (“eunuch eels), and unlike other eels, they don’t leave lakes and rivers to spawn in the Sargasso Sea. They simply stay in fresh water, eat, and get big.

We do have some evidence of what happens to European eels that don’t go through their normal life cycle.

In 1859, an eel was confined to a well in Sweden. It remained trapped in the well until it was recaptured in 2008. It was over 149 years old, and yet, it had survived in fresh water all this time. It was 53.5 centimeters  (21.1 inches) long, and its eyes were unusually large.

Now, a 21 inch eel is hardly a giant animal. However, it is possible that an eel living in a more nutrient-filled environment than a well, could grow large during such a prolonged life.

However, I don’t think that the supposed large eels are eels that simply remained trapped in freshwater due to confinement or sterility. I think there is something else at work here.

One aspect of natural selection that is often left out is the human element. Now, we often hear about the peppered mouths of Britain, which come in two basic color morphs. One is lighter and perfectly camouflaged against a tree with lichens and moss on it, while the other is darker and better camouflaged against soot covered tree. With the Industrial Revolution, the darker moths proved to be better camouflaged against bird predation, and thus, the majority of the population became dark-colored. (This trend has since reversed as Britain has tried to clean up emissions from power plant and factories.)

Now, that is a textbook example of how human effect natural selection. I have also postulated that the ancient wolf population from when modern wolves and domestic dogs descend was originally much more dog-like. The wolves were curious about people and were easily tamed. When we began to domesticate other livestock, dogs and wolves began to fully split, as man selected dogs that were unlikey to prey on livestock and man began killing wolves on a large scale. This selection pressure on wolves ratcheted up as the Industrial Revolution made poisons, traps, and fire arms more readily accessible. We have selected dogs to be extremely tame and docile. They don’t fear new things as much as wolves do, and dogs have also evolved innate human reading abilities and associative learning abilities that make them rather interesting animals. Our pesecution of wolves has selected for more reactive, nervous, and fearful animals– animals that are nearly impossible to tame, even if bottle-reared. That’s why I think there is such a heightened difference between the two animals, even though every genetic study suggests that they are very closely related and are probably the same species.

Now, what does all of this have to do with eels?

Well, I think we have to consider eels as fish. More specifically, I think we have to consider eels a commercial fish. Indeed, commericial fishing is really taking its toll on the European eel. Today, it is considered a critically endangered species, and it is on the ICUN Red List. Typically, the reasons for its decline are thought to be the building of dams on rivers, which preven the eels from returning to freshwater to spawn. PCB pollution has recently been blamed for crash in European eel populations.

The European eel is in such a bad state that Norway recently banned fishing for European eels in its waters.

However, there is another factor that has also harmed eel populations. They have been overfished. Eels have been a common “peasant food” throughout European history. In fact, it is only been recently that they have been elevated to fine French dining.

And what happens to all fish species when they are overfished? In virtually every case, the size has been greatly reduced. People take the big ones. One big fish is less labor intensive to land than a bunch of little ones. And let’s not forget that some people trophy fish out the large ones.

And very often, the reduced size in fish species is reported on the news, like this story on whale sharks, this story on Alaskan and Russian salmon (which have a the opposite life cycle of eels– returning from the sea to their natal streams to spawn), and this one which blames commercial fishing for reduced fish size.

The unofficial and unverified maximum length for a European eel is 79 inches (200.7 cm). Now, that’s not a 2o or 30 foot eel, which I don’t think is likely with this particular species. However, if true, that eel was over 6.5 feet long.

Perhaps before European eels were widely exploited as a food source, eels of this size or possibly larger existed in European waters. It is also possible that there could be a throwback or two that still remains in the European eel population. It is also possible that these large eels were more common in more recent decades in remote lakes and rivers. When holiday makers visited these lakes and rivers and encountered these relict populations of eels, they thought they were monsters.

Now, I don’t have hard evidence that eels were much larger in the past. Because they were thought of as a peasant food ( and I’m not blaming peasants for eating them–just for the record), it is unlikely than any good records of them were ever kept in those early years. We’ve only started to pay attention to them when we’ve come to realize that the European eel is now critically endangered. What records we do have come from the past couple of hundred years– centuries after they became common table fare. We may simply be basing our maximum size for the European eel on what is really a species on the brink.

The truth is that in the very near future there might not be any European eels of any size left. But I think it is a logical fallacy to assume that we can determine the maximum size of European eels from the current over-exploited population. Maybe in some remote lake or river, there are a few rather large eels remaining.

The giant eel theory is well worth exploring, but I think the evidence for it may disappear before any can be found, if that evidence hasn’t already disappeared through the centuries of overfishing.

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Weird Tsunami Fish

Just when you had the world figured out, it suddenly couldn’t get any stranger!

Source

I know what some of these are, but some are a total mystery!

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Megalodon hunting juvenile blue whales. White sharks don't get this big. The Megalodon may not have reached this size either.

Megalodon hunting juvenile blue whales. White sharks don't get this big. The Megalodon may not have reached this size either.

I’m sure everyone has seen  Jaws, along with all the cheesy sequels. They are rather like bad rip-offs of Beowulf. Just when the large white shark is killed, another even bigger one shows up, probably its mother out to avenge the death of its offspring.

But how big do white sharks get?

That is something of a debate.

The one in Jaws was 25 feet long, which is actually not much larger than the species gets according to official sources. In one of the cheesy sequels, the shark is 35 feet long.

But how big do they get?

Officially, their record size is around 20 feet. The largest on record was caught off the coast of Cuba. It was 21 feet long, just slightly smaller than the shark in Jaws.

However, there are reports of white sharks exceeding 30 feet in length. These must be taken with a grain of salt.

Why?

Well, there is a somewhat similar species of shark that does attain those lengths. Today, we know them to be very different from the white shark. I am, of course, talking about the basking shark. Basking sharks can reach lengths approaching 40 feet, and if one is seen swimming in the water, it looks something like a white shark. But it lacks the rows of sharp teeth, for it is a filter feeder. To make things even more confusing, different authors refer to the white shark as a “basking shark,” including Kipling in his short story “The White Seal.”

The supposed largest white shark was taken in herring weir in New Brunswick. It was said to be 37 feet long. However, the largest basking shark was caught in the Bay of Fundy, not very far from where this supposed white shark was captured. It was caught in a herring net, which does suggest that the animal in both cases was the basking shark.  Herring and basking sharks eat the same plankton, and it would be reasonable to find herring and basking sharks in relative proximity to each other.

White sharks also avoid boats. They seem to know that people are forever gunning for them, so if they see a boat, they usually try to avoid it. A basking shark will ignore the boat and continue slowly swimming. That means that the basking shark is more easily taken by fishermen than the white sharks are. And it would make sense that such large sharks wound up captured by herring fishermen.

So we can dismiss the New Brunswick giant white shark as a big basking shark.

But are all of these animals misidentifications?

There is always this Megalodon hypothesis that pops up now again. Supposedly, there is a relict population of Megalodon stalking the depths of the world’s oceans. It is most likely poppycock.

The Megalodon is thought to be a close relative of the white shark, and some taxonomists place it in the same genus as the white shark. It is believed to have reached a length of over 50 feet. And its diet was mostly whales and other marine mammals. It most likely became extinct 1.5 million years ago.

It may have been in the same genus as the white shark, and it is thought to have looked a lot like the white shark, just much larger. My guess is that the oceans of today simply do not have enough marine mammals to even support a relict population of this species. During its halcyon days in the the  Miocene and Pliocene, there were many more species of whales and other large sea mammals. The numbers of these creatures dropped off in the Pliocene, and those that remained migrated to the polar regions, where the shark could not survive.

So it is very unlikely that the supposed giant white sharks are actually Megalodons.

So how big do white sharks get?

Well, we have some numbers based on authenticated records.

We have three recent reports of 23 foot white sharks. These have been met with scrutiny, and one of them has been disproven. In 1987, a supposed 23 footer was caught off the coast of Malta, and that same year, another alleged 23 footer was caught off the coast of Kangaroo Island, South Australia. The one in Malta was later analyzed based upon its photograph to be no more than 18 feet long. The one in Australia has not been verified. However, another was caught in 1997 in Taiwan, it was also said to be 23 feet long, but again, no one has verified its size.

The official world record length for the white shark is 21 feet, which was captured off the coast of Australia. There have been several reports of 20 footers, including one that showed up in Prince William Sound, Alaska, were it tried to steal a Pacific hailbut from the line of sport fishermen.

19-21 feet seems the most likely maximum size for the white shark. It is possible that larger fish existed long ago. After all, one thing ichthyologists have noted is that fish specimens have decreased in size. over the years. This reduction in size has been observed in so many species, some of which were taken as trophies by sport fishermen and others were taken for their meat. Large sharks were probably taken because of the supposed threat they posed to swimmers. Like ridding the forests of wolves, bears, and big cats, man believed that removing large predators from the ecosystem was a duty. It has only been recently that we have realized the error that was made.

So maybe there really were 23 foot white sharks.

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Imagine seeing one of these swimming around in a Midwestern lake.

Imagine seeing one of these swimming around in a Midwestern lake.

The question of how far up a river a bull shark can live has often brought debate. Although one was found over 2,000 miles  up the Amazon in Peru, it is thought that bull sharks cannot survive very far up North American rivers, and they certainly could never be found in the cold rivers and lakes of the Northern tier of states. Or could they?

It is well-known that bull sharks can tolerate fresh water. In fact, their tolerance for fresh water has resulted in taxonomists naming them after the rivers and lakes they frequent. In Southern Africa, the species is called the Zambezi shark.In Australia, it is known as the Fitzroy creek whaler, and in Lake Nicaragua it is called Nicaragua Shark. In all of these cases, it was thought to be an endemic river species. Now, we know them all to be bull sharks.

Several species of true river sharks can be found in Asia and tropical Australia. These are in the genus Glyphis. The most famous is the Ganges shark, which is quite endangered. It is often considered quite dangerous and is blamed for attacks on Hindu pilgrims. However, it is very likely that this species is taking the blame for bull shark attacks.

Now, in North America, the only river shark we have is the bull shark. It is the species that is most likely responsible for the shark attacks that happened at Matawan Creek, New Jersey, in 1916. It is likely that a great white was preying on people on the Jersey Shore at the same time, for a great white was caught in in Raritan Bay with human remains in its stomach. It is also possible that the shark had been feeding on corpses lost at sea. After all, the First World War was raging at the time, and great whites have been known to swim vast distances across the ocean. However, there were shark attacks on the coast during that time period. These could be attributed to a great white, which are known to hunt in the surf.

Because they happened at roughly the same time as the shore attacks, the attacks in Matawan Creek were blamed on the same shark. However, great whites cannot swim up freshwater estuaries. They cannot regulate their salt content in that sort of water, and they die. Bull sharks, however, can swim up fresh water rivers rather easily. Most experts believe the Matawan shark was a bull shark.

Officially, bull sharks have made it up the Mississippi as far as Illinois. In the town of Alton, Illinois, which is above St. Louis, two commercial fisherman caught a bull shark in the river. This shark had been raiding their fish traps, and they decided to catch the culprit once and for all. They set a big trap, one that would catch the biggest muskellunge or pike.  They were certainly shocked to find that it was a shark raiding their traps.

Now, there is another interesting story that should be added. Although now official record of it exists, a man was supposedly attacked by a shark in Lake Michigan in 1955. This attack supposedly happened at one of the beaches near Chicago. The shark may have traveled through the Illinois River and then took a trip up the Michigan and Illinois Canal. However, the canal was disused and parts of it had already started falling in. It could have made it up the St. Lawrence Seaway and into the Great Lakes system. How it made it through the locks and dams on the St. Lawrence is a very good question. Further, bull sharks have been found only as far north as Massachusetts. None have been reported in the Gulf of St. Lawrence, where they could enter the river and seaway.

This story may be an urban legend.

However, I have found a more recent story that might add some credence to the Lake Michigan shark legend.

In the winter of 2006, sharks were documented in Minnesota and Wisconsin. Yes, you read that correctly.  Not only are both of those state quite far from the ocean, they are also known for their less than temperate winters. The Mississippi’s source is in Minnesota, and Minnesota and Wisconsin are the first two states it passes on its way to the Gulf of Mexico.

Our story begins in Minnehaha creek, not far from the city of Minneapolis. There, a ten year-old girl named Laura Zimmerly found three shark’s teeth. She brought the teeth to Minnesota DNR biologist Dan Marais. Marais’s first reaction was that these were fossilized shark teeth. Fossilized shark teeth were not uknown in the Upper Mississippi region. However, two of the teeth were rather obviously not fossils. They looked like they had just fallen from a shark’s jaws.

The two teeth were sent to the fisheries department for further analysis.

The teeth were those of a juvenile bull shark.

Now, that was in the autumn of 2005. The two teeth were interesting, but because they were of a juvenile, no one really got excited about them. The case of the Minnesota shark teeth was classified, and no one made a big deal about it.

Then in Februrary of 2006, a pickup truck went through ice in Lake Pepin. Lake Pepin is a widening of the Mississippi between Wisconsin and Minnesota. It is also a lake with its own lake monster, known as “Pepie.” (Now that first photo looks hoaxed). However, when that truck went through the ice, a real live monster made sought refuge within the vehicle.

Salvage divers reported a shark that had moved into the vehicle. Now, it could have been a sturgeon, so Wisconsin’s DNR sent biologists to go check it out. In about 18 feet of water, the biologists discovered a five foot-long bullshark resting within the truck. It was comatose and near death. The cold water and the lack of trace elements in the Mississippi River water were taking their toll upon the creature. It had sought out the truck as a place of safety.

Now, the story of the Minnehaha shark teeth suddenly became of importance to the authorities. Minnesota’s DNR sent a team of researchers who used electric current to stun the fish of creek. Among the fish that were stuned were two very small bull sharks. These baby sharks were christened “Frankie” and “Lenny” (from the movie Shark Tale). They were sent to the Minnesota Zoo, where they were reacclimatized to salt water.

Now, it is thought that the five-foot in Lake Pepin and these two juveniles in Minnehaha Creek swam up the Mississippi becaus of Hurricanes Katrina and Rita. The storms washed large amounts of pollution into the Gulf of Mexico, which killed off lots of prey species for the bull sharks. Bull sharks tend to live very close to shore, and they also tend to live near river mouths. With the temporary extirpation of typical prey species, these sharks swam up the Mississippi. Because the locks and dams were being opened to prevent flooding, the sharks continued to swim up the river until they were very far from their typical range in the Mississippi.

However, the teeth that Laura Zimmerly found were tested for their age. The DNR tested the tannin stains on the teeth. Tannin is the residue from leaves that drop into the river. The longer the teeth were in the creek, the more stain they would have. The teeth were found to have been in the creek for seven years. That means that bull sharks have been occasionally frequenting the Upper Mississippi for a really long time. It also means that bull sharks are coming up these rivers with far more frequency than had previously been assumed.

Minnesota authorities banned swimming and diving in Minnhaha Creek below the famous Minnehaha Falls that summer. No one wanted to be the first Minnesota shark attack victim.

Now, closing down the creek below the falls to swimmers sounds rational, but I have to offer this caveat. The bull sharks of Lake Nicaragua are only able to enter the lake the lake through the San Juan River, which has fast flowing rapids and falls. The sharks were once thought to be trapped in the lake. However, the sharks never seemed to be reproducing in the lake. It was later found that the sharks were jumping the rapids  on their way into the lake. I doubt that the bull sharks could jump Minnehaha Falls, but it was also doubted that they could ever make it that far up the Mississippi.

Now, I have not read of any sharks making it up into my neck of the woods. The rivers in my area all drain into the Ohio, which drains into the Mississippi. Bull sharks have been found in the Ohio, but they have not been found outside the Lower Ohio drainage.  As far as I know, no sharks have been found in the Upper Ohio or its tributaries. But if a shark could make it to Minnesota, it certainly could make it to West Virginia, and it might be able to survive a little longer in the winter. In fact, if the winter was a very mild, it might be able to survive.

However, if there is going to be a shark in West Virginia, it is more likely to be found in the Potomac drainage system. The Potomac is much closer to a body of salt water (Chesapeake Bay), and the sharks have been seen in the Potomac as far up as Washington, D.C.

Now, things wouldn’t be so bad if bull sharks weren’t known for their very high levels of aggression. In fact, most shark attacks in the world are probably from bull sharks. Bull sharks have very high levels of testosterone. In fact, they have higher levels than bull elephants in musth. These high levels might make them more aggressive than other species. Further, they are typically found only in shallow water near river mouths. Those are the same sorts of areas where people swim and fish.

So bull sharks can turn up just about anywhere. However, I doubt that Minnesotans will be ice-fishing for them any time soon.

And they definitely won’t . Please read this post before leaving ANY comments that call me an idiot. I’m a fibber in this case, not an idiot. Remember, I’ve been reading Montauk Monster conspiracy theories for a week, so I thought I’d try my own hand at some “grade A bull-plop,” as “Mr. X” (Homer Simpson) once said.

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