Sunday, January 31, 2010

DALE DRINNON: Meeting Old Nic

Some years ago I came across a photo of a bull shark that had been caught in Lake Nicaragua and used as a plate in the book A Natural History of Sharks. The shark had teeth marks on its tail and the more I looked at the photo, the more I realized that the pattern of the teeth in the bite mark were unusual. They were set wrongly to be either a caiman or a crocodile on the one hand, or another shark on the other. I went back to get a copy of the photo later but later editions cropped off the unsightly bite mark from the photo. A native is holding up th shark in the photo which gives an exact scale.

The bull shark is known to be a man-eater, and in this case some unknown animal was chasing it and nipping at its tail while it ran away. It seems that the creature, whatever it was, did not get a good enough grip on the shark's tail so the shark got away, only to be caught later by the fisherman.

I did find reference for a porosus croc fighting with a bull shark but this is the wrong hemisphere for those crocs and the toothrow is different, being wider and more divergent in the back and with a peculiar notch in the front, and some of the marks seem to indicate a double toothrow.

Now alligator gars have been found occasionally in the Gulf of Mexico and in Lake Nicaragua, according to the Wikipedia entry, and it seems that although they are usually freshwater fishes they can also tolerate brackish or salt waters. The alligator gar is the second-largest fish known to live in North America, and ten-foot-long specimens are on record, while rumor has it that they can reach 18 or 20 feet long. They have vicious mouths with a double row of sharp teeth and at times they can be damn near unkillable (they are ganoid fishes and their scales are much tougher than ordinary fish scales, and it is said that sometimes bullets and axheads aimed at them only glance away making sparks)

And so I propose that Old Nic, the monster of Lake Nicaragua, is a large and surly type of alligator gar instead of being a plesiosaur or anything else. The encounter inspired me to make the mockup of the incident which I include above.

3 comments:

  1. It couldn't be an alligator gar. Those are native to only the United States.

    It could have been the tropical gar, which is a native to Mexico and Central America as far south as Costa Rica.

    However, they don't get as large as the alligator gar, although they do look very similar. The biggest on record are 1.5 meters long.

    The biggest alligator gars are something to behold.

    There are American crocodiles in Nicaragua's lakes.

    My guess is that it was some kind of toothed fish.

    It couldn't be an alligator gar.

    Maybe the shark was attacked by a great barracuda when it was in the ocean.

    These sharks do not stay in Lake Nicaragua permanently. They actually jump the rapids of the San Juan River to go between the lake and the Caribbean. Because of this, it is wrong to assume that this shark was attacked in the lake. It is a common misconception that these sharks are trapped in the lake. Studies that have tagged the sharks have found the same individuals in both the lake and the open ocean within a week of capture.

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  2. i can see why they would call that a lake monster serpent: the inside of the mouth looks just like the inside of a snake's mouth, only with more teeth. natsy, to.

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  3. Anonymous1:00 PM

    Retrieverman: you are mistaken. Alligator gar are artificially introduced in several locations and evidently illegally, including in Hong Kong and Central Asia, as my post indicated.

    Furthermore they are known in Lake Nicaragua. It is not known how they got there, but it is possibly through artificial introduction once again. They have also been reported in the saltwater Gulf of Mexico.

    Now if it is also at sea, that also answers you statement that it is a mistake to assume that the shark was landlocked and had to be bitten inside the lake. I did not say that was necessary. But on the other hand in the original photo the biter mark looks quite fresh and is not an old scar: therefore asuming that it was bitten IN the lake would only seem reasonable.

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