Puzzling goldfish question.

[Devilishturtles]

Ok, sooo maybe this is real basic and maybe it's not...

I was wondering the other day why it is that goldfish can breathe air from the surface of the water (and effectivley live without a filtered tank) and are not termed "labyrinth fish". What is it that allows them to do this if they don't have a labyrinth organ?

I bought this up in the chat, and we were all unsure.

Any ideas? Thanks in advance for tackling my curiosity

 

[bound_for_obx]

My guess is that the oxigen levels in the water are low. By gulping the air at the surface maybe they can sort of saturate the water near their gills with oxygen to help them breath. Now this is only a guess so please don't take this a gosple! lol
oh yeah pleas forgive the spelling... spell check isn't working.

 

[Menagerie]

Many fish had the potential to extract oxygen all along the GI tract--simple cutaneous respiration. Goldfish swallow air into the stomach, which is highly vascularized and oxygen diffuses into the blood. They do this to supplement their oxygen needs. They really rely on the gills for the majority of oxygen.
For some fun reading: http://www.biology.eku.edu/RITCHISO/342notes8.html

 

[bound_for_obx]

Thanks Menagerie! That certainly clears things up!

 

[Menagerie]

Thank my husband! I sort of knew the answer, but he cleared many things up for me too

 

[Devilishturtles]

Thanks Menagerie! Kudos to you, bound_for_obx, and Fluff (who helped me out in the chat with her best answer).

8)