Siluro - abbondanza e alimentazione negli areali di introduzione A torpedo particularly hungry and lack of skills 'to select prey
It' s a sad given that this blog receives most of its torpedo hits on the subject. Despite
Silurus glanis was one of the reasons why I opened the blog I think there are many other interesting topics to read in here, but it seems that most the other arguments do not attract visitors as Google searches or is this fish. Clearly, and 'became one of the controversial (and therefore more' popular) view of the country's fishing.
He and 'already' talked enough and frankly I think it is counterproductive to engage in a structured and informed discussion on this topic. It 'a little' theory of the mountain of shit (sorry French) applied to fish biology. Some of them with inaccurate or misleading information (see the case of fossil
or of '
electrofishing) and other touches to spend a lot of time to explain calmly and literary references that things is not like that'. Shoveling shit (oops, of new) and 'a tiring exercise and much more' difficult to produce, so the producer has' a clear advantage on digger.
I state that I hate having to go back to talking catfish. I think I've already 'electronic ink spent enough on the subject but that' s an update almost a duty.
First of all, a major update to the article "
but what eats a catfish? . A Finnish researcher on loan to France for a period of research has analyzed the diet of the torpedo and its trophic position nell'areale introduced by the analysis of stomach contents and stable isotope analysis (SIA and SIRA).
This technique, to which I had already 'mentioned in the previous post and' relatively new but widely used in the field. For relatively new and that means' was invented by a 20th years ago, called a tenth of years ago and now used in almost every possible way for 5 years now. Basically consists in analyzing the spectrum of these creatures in an environment and record their isotopic ratios (which are peculiar and conservative) and then compare them with those of the species that you want to know the diet or trophic position (usually in terms of what kind of class).
Beyond 'oversimplified explanation of the technology we see what were the results:
- similar trophic position among young people and adults (Obviously with the growth in size)
- adult diet consists of mammals and birds regularly
The article 'available and public, and' found at this link (in English):
http://www.int -res.com/articles/ab2009/8/b008p137.pdf Now, this article clearly can not 'be considered definitive proof valid everywhere but certainly escape many of the doubts that existed in my previous article. You can 'say that the result is not surprising as exceptional (it was assumed that the power was at that level) but how much and' a rigorous confirmation of a hypothesis that was also made as a hobby. To put it in my terms: a fish eats anything that manages to slip into his mouth when he can eat whenever you can 'eat. It is a bit 'for all the fish.
The road 'now truly open space (or even asphalt) for all research groups and associations that want to really affect the argument, there are no more' excuses. Other
update the distribution and density of the torpedo 'population. Lately, and 'often heard that the populations are in decline, but rather that it must contract because by now should have reached their maximum expansion, and now nature should regulate itself.
Maybe they forgot to notify the torpedoes in the province of Ferrara and the war 'ended, these as the Japanese missing in the Pacific Islands, continues with impunity .. Seriously
parted a recent study by the University 'of Ferrara numbers emerge quite disturbing. In addition to confirming the trophic position and diet seems that people are now well structured and to come to density 'awesome. In all the drainage channels reaching more than 50% in borderline cases around 70%.
The decline of the catch, if there 'was, by some anglers, it seems to be caused by anything but a decrease in the number of torpedoes.
Even this article is available for download thanks to our friends at Esox2000:
http://digidownload.libero.it/esox2000/art...i/siluroCLR.pdf All this hubbub about catfish and 'counterproductive in terms of conservation. If for any search, for each inspection, you will always be a hornet's nest 'everything slowed down dramatically, both positive and negative actions. Besides the fact
to divert attention from other species that deserve the same. There are fine articles about the potential impact and determined to species such as roach (Rutilus Rutilus
), the bream (Abramis brama
) ASPI (
Aspius aspius ) but also the pikeperch (Sander lucioperca
) or bass (Micropterus salmoides
) on the ecosystems in which they are introduced. Pero ' These species are generally ignored.
We'll talk more soon. Promised.
Bibliography:
Syväranta et al. 2010
Castaldelli et al. 2010 in press
