Drowning Bettas

[Dano]

I have heard that Labyrinth Fishes can drown if they cannot reach surface air. I have not read any scientifically based evidence to prove this belief, only statements from many non scientific individuals. I would like to see a bonafide scientific statement that specifically states that they will drown if they cannot get atmospheric air.
These fish have completely developed gills as well as the labyrinth organs. They can only survive in the air for brief periods until they dry out. They can survive in low oxygen environments such as a slowly drying puddle, but they die when the water is gone.

In the spirit of debate, someone please enlighten me on this with hard evidence.

Dano

[lemuelpr]

No science here, but labyrinth fish like bettas has developed this accesory organ to get more oxygen to their systems. Why? Well, to adapt to low oxygen waters were they live like muddy stationary waters. But their gills do work. In a tank with moving water which is well oxygenated you can see the spending tons of time in the bottom of the tank without needing to surface for air. Probably the statement you mention is about having them in deep bowls were oxygen cannt diffuse so easily. There, if they don't have access to the surface to compensate for the low oxygen levels, they can probably drown. Any one has any other knowledge or opionion?

[Dano]

Thank you Lemuel. That was very informative.

Everyone is invited to express their thoughts on this subject, so please join in.

[Bernie]

As you know, I am one of those non-scientific individuals that made the statement pertaining to that fact. It is true that Anabantoid (labyrinth fish) fry are born without the labyrinth organ and do not need to breath atmospheric air, but as they mature and develop the organ, it is my understanding that these fish need both the gills and labyrinth organ in order to survive, as relying on the gills alone won’t produce enough oxygen for them.

I did find some articles written by professors from educational facilities i.e. Hawaii Institute of Marine Biology stating the fact that the fish will drown, as in these excerpts (full article through links):

“If a labyrinth fish is denied access to the air it will drown because the gills alone will not provide sufficient oxygen to the fish”

http://209.85.173.104/search?q=cache...ns/gourami.pdf

“Bettas are most distinguishable by their accessory breathing organ called a labyrinth. These are folded tissues in two chambers of the gill cavity; these labyrinths are supplied with numerous vessels and can absorb oxygen from air. Basically, Bettas need to surface in order to replenish their air supplies, if they are denied access to surface air, they will drown.”

http://209.85.173.104/search?q=cache...SH%2520LAB.pdf

In addition, many fish sites also mention it, as this one:

“Bettas have a special respiratory organ that allows them to breath air directly from the surface. In fact they inherently must do so. In experiments where the labyrinth organ was removed, the fish died from suffocation even though the water was saturated with oxygen. For this reason, Bettas must have access to the water surface to breath air directly from the atmosphere.”

http://user.aol.com/casey144801/aquarium/index26.htm

Sorry! I do not know how the conclusion was reached that the fish would drown or what specific studies were carried out (apart from the experiment mentioned above) to substantiate the statement and provide you with hard evidence. Many things we believe to be true may not always have scientific research to back it up. I for one do not wish to test the theory by torturing a fish to prove its validity. I tend to believe that there is truth to the statement!

[Sharon]

I've read many arcticles that support the theory that labyrinth fish will drown if thy are denied acsess to the surface. My Betta and Gourami both spend time at the surface "breathing"...it seems to be what comes naturally for them. Whether it's absolutely necesary or not, I wouldn't know, but the aim of a fishkeeper is to have happy fish, so I'm going to assume it is necessary.

[Dano]

Thank you Bernie. The articles you posted are about the same as many that I have read, but I am still inclined to see the issue the way that Lemuel has submitted. This does not mean that I am totally convinced one way or the other. I hope many other members will submit their input on this.

Thanks everyone and keep the data coming