Microbiologists and fish researchers have discovered an entirely new type of symbiosis: bacteria in the gills of fish that convert harmful ammonia into harmless nitrogen gas. Fish produce a lot of ...

Freshwater fish take up chemicals from the surrounding water through their gills Biologists have cast doubt on the long-held theory that fish gills evolved primarily for the purpose of breathing. The ...

When many people hear “ammonia”, they commonly think of commercial cleaning products or the pungent odor that comes from cat urine. Yet, many experienced aquarium keepers know that ammonia is one of ...

The transfer of oxygen, carbon dioxide, and ammonia across fish gills is waterflow-dependent, oxygen being the most flow sensitive and ammonia the least, in the reverse order of their solubilities.

Gill evolution Fish gills evolved to balance pH, not breathe, suggests a new study. This goes against the traditional assumption that gills first evolved so fish could get more oxygen as they became ...