Nature Blog Network
Showing posts with label NEW AND REDISCOVERED. Show all posts
Showing posts with label NEW AND REDISCOVERED. Show all posts

Sunday, 19 April 2009

THE UNIDENTIFIED FISHES OF YOUTUBE PART TWO: An Unidentified Submarine Object

Round 2 of the unidentified fish blogs. Here, we go all crypto and look at a U.S.O. from a lake somewhere. (Sadly, we have no idea where, which makes things more confusing). In the film, we see a group of small orange-yellow “things” surfacing and dropping repetedly, before dropping and not reappearing. This is clearly not one animal, so the cameraman's idea that it is a manatee is so wrong that I am going to stop midsentence.







Little groups of the things break off from time to time and disappear quickly. Now, I can think of two suggestions as to what it may be, but they both have their faults.

1. A group of small fish that are being corralled into a ball by an organised group of predators. Depending on where the footage was filmed, it could be a group of bass (small or large mouthed) or perch that are attacting the small fish. This accounts for the rising and falling of the fish in the water column plus the smaller groups splitting off. The disappearence of the fish occurs when the predators are full, and leave to digest their meal. However, if predators were attacking, there would be some splashes from boh the small fish, and larger splashes from the predaors. Plus, bright orange bait fish? I've not seen many species that are this colour.

2. Snakehead fry. Yay! Snakeheads! When snakeheads spawn and the eggs hatch, the parents push the young up to the surface to fill their “lungs” with air. If the babies don’t inflate their “lungs” quickly, they die. Snakehead fry are bright orange-yellow, which accounts for the colour. They are also not prone to jumping out of the wach much, which accounts for the lack of surface movement. The small groups are quickly herded back into the main group by one of he parents, which accounts for the short-lived nature of the small groups. At 2:21 a small fish jumps out of the water. The orange group drops down again, probably because the adults moved off to get rid of this interloper into their area, before surfacing again when the adults push them back up.

This too has its problems. The only footage I have seen of snakeheads exhibiting this behaviour shows them doing it in shallower water, usually with some cover from plants and rocks. The main argument against it however, is that snakeheads are not found in English speaking countries (as natives), and any local would have no trouble identifying a cresh of baby snakeheads as being so. This could well be video footage of introduced snakeheads in the USA breeding (as if there was not enough evidence), if it is indeed from the USA.

Friday, 17 April 2009

THE UNIDENTIFIED FISHES OF YOUTUBE - Part Three

Time for a slight change now I feel. We can now look at a number of different videos showing undiscribed fish. First is this handsome fellow:

It is another cafish, but this time it is from the family Aucheripteridae, or the driftwood catfishes. These are a cracking group that is rarely seen in captivity because few people want a catfish that sits under driftwood all day and is generally of a nervous disposition. I, obviously, love them to bits.

I have no idea what this fellow is, so that will do for now on taxonomy. There is one interesting footnote to this specuies though. The chap in the film is a male which is shown by a very strange modification. If you look at his anal fin, he first few rays of it are modified into a copulatory organ much like that seen in fish like guppys and platys. This family of catfish are the only ones to have evolved such a device, making them a very interesting group indeed.



Here is another Loricariidae catfish. Nothing to say here other than it is a male again.



http://www.youtube.com/watch?v=stWLsqJFfRs

THE UNIDENTIFIED FISHES OF YOUTUBE PART ONE

Youtube is a powerful tool. I spent some time this morning looking around its archive to try and find something interesting to witter about for a bit. So here we are, a look at the undescribed species of Youtube.

We had best start with some fish. First we have this very attractive Loricariidae, or, a plec. These are common inhabitants of aquariums, but they are either one of the huge species which are sold as “only growing to “4”” and the size of the tank”, or one of the stunning “L-numbers” which are almost always wild caught, very pretty and astoundingly expensive. £30 is about what you need for one of the more common species, but individuals selling for multiples of hundreds are fairly commonplace. This is an adult male, so at about 7cm he is one of the smaller species. The thickened first ray on his pectoral fins show him to be a sexually mature male, ready to defend his site from all comers.

It is a Venezuelan species, which in itself is nothing unusual, but if in the video you look closely 26 seconds through, you should notice fronds on the front if he fish’s sucking mouth. These are modified sensory barbels which help in the search for food. Not many Loricariidae have these, so this species is unusual in having them. It is thought to be from the genus Leporacanthicus, but appears to be the smallest species in the group: the others all get over 20cm in length. Its dorsal fin appears to be much more triangular than all the other species in the genus, but hey, I am not a taxonomist.

Yet.