When asked that question, Michael replies: “Usually it cannot, but complex changes occur around its gills, which enable it to filter out the salts found in seawater.
As for fish, whole fish should have clear eyes, red gills, and unmarred, firm flesh, and fillets and steaks should be bright and shiny, without a strong and unpleasant odor.
These eight-inch [20 cm] crabs, which have modified gills for breathing air and make only periodic visits to the sea to breed, help to nurture deeply rooted trees.
Describing the banqueting bears’ eating ritual, one eyewitness said: “Selecting the specimen they want, they put one paw on the head, then strip the skin off from the gills back, exposing the flesh on which they feast.”
Thanks to the ampullae of Lorenzini—tiny ducts peppered around their nose—they can detect the weak electrical fields emanating from the beating heart, the gill action, or the swimming muscles of potential prey.
Today, with the introduction of trawlers and nylon gill nets that can stretch for great distances and scoop up tons of fish in deeper waters, overfishing threatens the ecology of the lake.
Dan Gill answers: “To test whether Warren’s Shaft was in fact a natural sinkhole, we analyzed a fragment of calcareous crust from its irregular walls for carbon-14.