In addition to skin patches, other symptoms are pale gills, lethargy, loss of appetite, and difficulty swimming. Be aware ...

1) Fish kept in ice for over two days are not good. Check the gills; they should be red in fresh fish and pale in spoiled ones. 2) Some may apply chemicals or ice to maintain gill color.

Analysis of 33 fish species demonstrates that gill surface area is a primary determinant of oxygen uptake and growth in fish, consistent with the Gill Oxygen Limitation Theory.

The genes that build the cartilage of fish gills were repurposed to build the cartilage in mammals’ outer ears. Skip to main content. Scientific American. January 22, 2025. 7 min read.

After being swallowed alive, Japanese eels were able to escape from a predator fish’s stomach and swim to freedom through the fish’s gills, new research shows.