Another point is that this myth was dismissed by most in the
professional aquarium keeping industry (including in fish illness
seminars I attended), it was not until the Internet that it exploded
that is suddenly became truth to many via non science based blogs
re-posting the same information as an attempt to explain to many what
they were seeing was tail biting like one might see with a stressed
bird.
Most of these blogs are regurgitating the same information (copy &
paste) even the same diagram. One blog was by a friend (NippyFish) that
I know was hijacked by a Russian (where I have been attempting to help
her with DMCA acts that so far have gone nowhere, thanks Google), so
this is far from trustworthy.
Yet, even with these facts presented to them, a few aquarium keeping groups such as the otherwise intelligent "Fish Tank Enablers" continue to push this myth.
An interesting point that many of these non professional based blogs
have in common is they state that certain bite shapes in tail damage are
proof of biting when in fact this is simply more an indicator of the
pathogen. The so called "Betta biting chunk" is typical of a Columnaris
infection where by chunks of tissue simply fall off.
More common though of Betta Fin Rot is a more ragged deterioration which
these blogs claim (correctly) is more from fin rot. Problem is Fin Rot
is not a disease per say, rather symptom (just like Septicemia or so
called Red Pest). This more ragged fin damage is more common of an
Aeromonas or Pseudomonas infection.
Here is one of the copy & paste pictures that these blogs have
shared that I have corrected to the correct diagnosis as per known
science:
Of course one might ask what does it matter?
Why getting this right matters is such myths distract from the real
causes and addressing these, especially if a case of fin rot is
involved.
This especially becomes critical when the fin rot is caused by
Columnaris, albeit a less common cause of such damage, as Columnaris can
be an aggressive infection if not addressed while the misled fish
keeper attempts to address an incorrect cause.
Luckily often Columnaris is stress related, so the non experienced
aquarium keeper removers the stressor and boom, they think they cured
their Betta tail biting and the myth goes one!!
While this myth is maybe not as easy to dismiss for some, we also
need to compare to another myth that is; that is that Melafix is harmful
to Bettas and certain other fish where observations to not hold up to
science based scrutiny.
Just because we see something does not mean the cause is what we see.
It is also up to those who make this claim of stress induced tail biting in Bettas to prove
that this is indeed the case since this goes up against previously
established science (not the other way around for those holding to the
science already established to prove themselves).
References:
Burden of proof
Wikipedia; Evidence (Science)