Fish intelligence in paradise fish ("Macropodus opercularis") which avoid places where they have experienced a single attack by a predator and continue to avoid for many months. A number of studies have shown that fish can retain information for months or years. Anecdotally, channel catfish ("Ictalurus punctatus") can remember the human voice call announcing food five years after last hearing that call. Goldfish remember the colour of a tube dispensing food one year after the last tube presentation. Sockeye salmon still react to a light signal that precedes food arrival up to eight months since the last reinforcement. Some common rudd and
Canned fish canned tuna is used for sandwiches, 22 percent for salads, and 15 percent for casseroles and dried, packaged meal mixes. Other fish that is canned includes cod, mackerel, herring, and pilchard (a type of sardine). Canned fish Canned fish are fish which have been processed, sealed in an airtight container such as a sealed tin can, and subjected to heat. Canning is a method of preserving food, and provides a typical shelf life ranging from one to five years. Fish have low acidity, levels at which microbes can flourish. From a public safety point of view, foods with low acidity