Fosters Island Rule Applied to Lake Monsters

Crypozoology is a favorite subject of mine and anything on this topic will get my attention. Of special personal interest are lake monsters, particularly those of the sea serpent variety. These are of the type like the famous Loch Ness monster and the water horses of Europe with their New World cousins like Champ or Ogopogo. Based on descriptions, locations, and other information, I propose that these lake monsters are unusually large specimens of a known species caused by “insular gigantism” AKA the “Foster’s Island Rule.”

Here is some basic information commonly reported about these watery beasts.

These aquatic crypto-creatures are most often sighted in large inland bodies of fresh water in temperate zones.
Are described as looking like large snakes 30 feet or longer and a foot in girth.
Swim with either a serpentine motion or an up-and-down undulating motion.
As they swim, they often appear as a series of humps rising up from the water’s surface with a head occasionally appearing at the front.
Have often have a dark slimy skin, small scales or both.
European lake monsters are often described as having a horse like head, catfish like whiskers, and a mane on its neck.
American varieties are often described as having a snake like head without a mane.
They remain deep underwater most of the time but will come up to the surface.
Are rarely seen during the day and are occasionally encountered at night.
Most of the lakes that hold these water monsters have no direct waterway to connect to the nearest ocean, although some do.
The majority of sightings of lake monsters in Europe occur from the UK through Norway and Sweden as far east as Russia and Turkey.
The majority of sightings in North America occur east of the Mississippi River and north to the Great Lakes and Newfoundland.

The Theory

Foster’s Island Rule proposes that mainland animal species that migrate onto islands will grow larger or smaller due to scare resources and a lack of predators. A small animal from the mainland will become much larger and a large mainland animal will become much smaller on an isolated island. If these animals survive long enough, they will eventually become new species.

The growth of smaller animals into much larger ones is due to the island rule concept called “insular gigantism” and is what gives rise to animals like the giant Galapagos Tortoise. The isolation of the island environment allows such animals to exceed their normal size up to the maximum their physiology will allow and what the island habitat can support.

This island rule could explain these lake monster sightings given the fact that a lake is an island to a water dwelling animal. After giving a lot of consideration to aquatic animals like catfish, sturgeon, eels and amphibians as candidates for gigantism, I have narrowed it down to the American and European eel. Other than size, the fresh water eel fits the description, occupies the same range, and has instincts and traits reported of lake serpents.

These eels breed in the Atlantic Ocean and after being born they migrate into fresh water where they mature into adults. They live for between ten and thirty years in fresh water until they return to the ocean to breed and die. The females can range in size from two feet to as long as four or five feet. In the US, the American eel has expanded it’s original range due to human alterations to the watershed. It’s migration is not restricted to returning to a specific river, so it will take advantage of any avenue to travel up stream. The same can be said of the European eel. Although predators, they are preyed upon as well as under pressure from changing habitat and harvest by humans. Although once fairly common, both European and American eels are becoming rare and are close to being classified as threatened.

The instinct for migratory expansion into new waterways contributes to the likelihood that the eel could become landlocked in an isolated body of water similar to a Foster’s island scenario. Large scale flooding and other situations could find a small population of eels stranded in a lake that has few natural predators. It is possible that some eels may develop traits that arrest final maturity and cause insular gigantism to occur over the course of 30 years of isolation. Because they don’t fully mature and return to the ocean to bred, they would eventually die off until more eels made it into the lake. This would make lake monster sightings a rare occurrence that may reoccur decades latter or never again.

Other than it’s natural size, an eel fits the description. It’s nocturnal and hides in burrows under the lake bottom during the day. Due to their migratory habits they are found in the same range and habitats as lake monsters. Some questions to answer to support this theory are, if it is possible for a fresh water eel to grow eight times it’s normal size and if individual eels can do this in a single life time due to regressive traits or environmental factors.

Here is a link to some new research in this area that inspired this topic.

Monstor hunters coming to Ireland

However there is a theory that some eels never sexually develop. These eunuch eels as they are known, remain in freshwater and nobody knows just how long they live or how big they get. “It is believed that these mutations arse on occasion within a normal population of eels.

Makes sense.

If a large inland lake supports gigantism in aquatic species, wouldn't it follow that other creatures besides eels also mutate into larger versions of their common forms?

Very nice well written thread/post, and i like the theory too.

I've often wondered about the possibility of these creatures being cut off from where they once originated from and the possibility that due to a lack of competition by the same species (by being land-locked at times), now allows them to 'evolve' (for the lack of another word) to becoming much larger.

Nice thread!

Johnny

originally posted by: TheTruthRocks
If a large inland lake supports gigantism in aquatic species, wouldn't it follow that other creatures besides eels also mutate into larger versions of their common forms?

Of course, given the right conditions occur. The species in question would have to be rare or perhaps invasive, or the lake would have to be lacking predators but have a large enough food source for a common species. Some animals will continue to grow for as long as they live, so if they live long enough, no mutation is necessary.

I simply chose the fresh water eel because they are in the same range and habitat as the lake serpents are reported to be. Sturgeon and channel catfish are often thought to be what some have reported as lake monsters, but they don't fit the description as well as an eel. Then there are giant salamanders like the Hellbender or other species on the west coast, they only get to be about a foot and a half to two feet long while the Chinese giant salamander gets to four feet long I believe. I didn't consider water snakes because they wouldn't survive underwater as long as the lake monster can, particularly during the winter when the lakes are frozen over.

Also, the fresh water eel goes through a number of phases while maturing and if it doesn't reach the final phase when it returns to the ocean to breed and then die, it could continue to live and grow without leaving fresh water. Similar to some amphibians that remain in the water with gills and under developed lungs because they never mature to a full adult.

originally posted by: JohnnyAnonymous
Very nice well written thread/post, and i like the theory too.

I've often wondered about the possibility of these creatures being cut off from where they once originated from and the possibility that due to a lack of competition by the same species (by being land-locked at times), now allows them to 'evolve' (for the lack of another word) to becoming much larger.

Nice thread!

Johnny

In the case of the eels, if they can't make it back to the ocean to breed, they will eventually die. So, although there may be an occasional mutation that could cause an eel to stay in fresh water, they likely would not be able to breed, that is why these researchers in Ireland call them eunuch eels (though they are likely the larger females). It would be like having a medical condition where your body never leaves the growth spurt before reaching sexual maturity.

The idea of an isolated animal growing to gigantic size has been on my mind for a long time. When this new study came out, it was what I'd been thinking for a while now. I just never looked in to it to find Foster's Island Rule to give it a foundation to work from. Of course Darwin laid the foundation with his study of new island species that were closely related to mainland ones.

The main problem with choosing the freshwater eel as lake monster is the differences in the description of European and American lake monsters.

Locomotion: They are mostly reported as swimming with an up-and-down undulating motion at the surface of the water, but occasionally with a side-to-side serpentine motion. However, eels swim side-to-side and don't normally come to the surface. But if they became giant sized, they may be coming to the surface find larger prey like turtles and aquatic birds. If this is the case, then perhaps swimming on their sides may aid them while hunting such prey by allowing them to see them better. This would produce an up-and-down motion at the surface that produces the visible humps.

Features: Long and snake like fits well and with European monsters they are described most often as looking like an eel. However, in Europe they are said to have a horse like face (and called horse eels), catfish whiskers and a mane on it's neck and the European freshwater eel doesn't look like that. Here's a LINK to a close up picture.

What does fit this description is the siren salamanders. These salamanders can get up to two feet long and are legless, or have a single front pair of small legs, and look much like an eel. They also have feathery gills behind their head that give the appearance of a lion's mane (not a horse's mane). They have under developed lungs, so they could breathe and issue hissing and other sounds like have been reported with lake monsters.

New species of giant salamander discovered

Concerning the amphibian family Sirenidae as a possible candidate for European lake monster. The more I look at this species, the more it seems like a good fit.

Sirens are generally eel-like in form, with two tiny, but otherwise fully developed, fore limbs. They range from 25–95 cm (9.8–37.4 in) in length.[1] They are neotenic, although the larval gills are small and functionless at first, and only adults have fully developed gills. Because of this, sirens most likely have evolved from a terrestrial ancestor that still had an aquatic larval stage. Like amphiumas, they are able to cross land on rainy nights.

Wikipedia Link

Unfortunately, their natural range is restricted to the Eastern US. Of course this doesn't mean there might not be a similar species yet to be discovered in Europe, one this is now extremely rare or recently extinct.

ETA: There is the possibility that small populations of siren salamanders were imported from the New World early on, however, this won't explain the earliest water monster reports in Europe.

Note: I was wrong that some siren salamanders are legless. They all have a small pair of front legs.

Eels which do not return to the ocean to breed do indeed sometimes become much larger (eunuch eels) - and this has long been postulated as one of the possible origins for some lake monsters

retrieverman.net...

a reply to: AndyMayhew

I wasn't trying to take credit by claiming that this theory was new, just that Foster's Island Rule can be applied in support of this theory. I'm sure if I've had a thought about something that someone already thought of it before I did.

In fact the crypo-expedition in Ireland is an attempt to prove this theory.

That article was OK and is pretty much what I propose here, but didn't go deep enough for me.

a reply to: MichiganSwampBuck

I was close to reporting the RikFlaxman post for T&C violations, but figured someone would catch it soon enough. Thanks guys, I'm actually surprised that one slipped through in to this topic, first time I've seen that happen.

Everyone seems to assume that lake monsters live in their lake permanently. I occurred to me many years ago that perhaps these lake monsters mainly live in the ocean, and only travel to inland lakes during breeding season. It would be interesting to see if there's any kind of seasonal trend to lake monster sightings.

a reply to: AndyFromMichigan

please explain COHERENTLY how - if your claim s true - 2 of the " famous " alledged " lake monsters - loch ness " nessie " and lale champlain " champ " - are able to do a " seasonal migration " undetedted

If a freshwater eel has become a giant eunuch eel and no long migrates to the ocean to spawn, then it merely hibernates in the mud on the bottom of the lake. Otherwise a lake monster must travel over land at some point to return to an isolated body of water that has no inlet or outlet when migrating. Possible for a giant siren salamander, but not for an eel, however, they too hibernate in the same way as an eel.

I did a small survey sampling of four freshwater lakes with well know lake monsters. Two in Scotland, one in Canada and one in the USA (and Canada). I include most common monster description, latitude, surface area, depth and fish species common to all these lakes.

Lake Monster: Ogopogo.
Monster Description: 40 to 50-foot-long, serpent
Lake: Okanagan Lake, British Columbia, Canada North America
Coordinates: 49°54′40″N 119°30′45″W
Surface area: 351 square kilometres (136 sq mi)
Average depth: 76 m (249 ft)
Max. depth: 232 m (761 ft)
Fish Species: Lamprey eel, Sturgeon, Salmon, Trout

Lake Monster: Champ
Monster Description: 10 to 30 feet long, small head, long neck, humps or coils
Lake: Lake Champlain, New York & Vermont, USA - Quebec Canada
Coordinates 44°32′N 73°20′W
Surface area 1,331 km2 (514 sq mi)
Average depth 19.5 m (64 ft)
Max. depth 122 m (400 ft)
Fish Species: American eel, Brook Lamprey eel, Sturgeon, Salmon, Trout

Lake Monster: Loch Ness Monster.
Monster Description: 25 feet long, small head, long neck, humps
Lake: Loch Ness southwest of Inverness Scotland
Coordinates: 57°18′N 4°27′W
Surface area 56 km2 (21.8 sq mi)
Average depth 132 m (433 ft)
Max. depth 226.96 m (124.10 fathoms; 744.6 ft)
Fish Species: European eel, Brook lamprey eel, European sturgeon, Salmon, Trout

Lake Monster: Morag
Monster Description: 25–30 feet long, serpent, humps
Lake: Loch Morar Lochaber, Scotland
Coordinates: 56°57′00″N 5°40′20″W
Length: 11.81 mi
Area: 10.31 mi²
Average depth 87 metres (284 ft)
Max. depth: 310 m (1,017 ft)
Fish Species: European eel, Brook lamprey eel, Sturgeon (occasional), Salmon, Trout

Common monster description details: Average of 30 ft long, serpent like with a long neck, humps on it's back
Average Lake Latitude: 51 degrees north (44 to 56 degrees north)
Average lake deepest depths: 730 feet
Fish species: Lamprey eel and Freshwater eel (except Okanagan Lake), Sturgeon, Salmon, and Trout.

a decent theory. But I have to wonder...if the sightings would be all over the place then. Almost daily.

a reply to: MarioOnTheFly

Freshwater eels, both European and American, are becoming rare. A eunuch eel would be rare in a large population of normal eels. If this theory is true then the appearance really large old eunuch eels would be even rarer as the years go by. If these eunuch eels must be isolated in a closed freshwater system to become over sized, then their occurrence would be even rarer due to the slim chances of getting caught in a closed body of water. All these factors would make a gigantic freshwater eel extremely rare.

I'm looking forward to the DNA report from the Loch Ness water that's coming out soon. The people involved in the study are hinting that their findings support at least one of the popular theories explaining what the monster could be. I'm betting on the eunuch freshwater eel theory being the theory they support.

Although, after watching a number of documentaries on lake monsters, I'm beginning to believe that most of these sightings have a number of reasonable explanations. Here is a list of those explanations.

Unusual wave patterns caused by wind over the area and surrounding terrain.
Floating logs and other material.
Moose or deer swimming across the lake.
Other misidentified aquatic animals.

I think of it like UFO sightings. Most can be reasonably explained with a small percentage that can't be explained. In the case of lake monsters, that small percentage of unexplained sightings is likely due to the giant freshwater eel.

Just as I thought, they are going with the freshwater eel as their candidate for the Loch Ness Monster.