1. Eating:
* Diet: Salmon are carnivores, meaning they primarily eat other animals. Their diet varies with age and location, but typically includes:
* Insects: While young, they feed on insects and other small invertebrates.
* Fish: As they grow larger, they consume smaller fish, shrimp, and other crustaceans.
* Plankton: Some salmon species may feed on plankton in their early stages.
* Digestion: After eating, salmon break down the food in their digestive systems, extracting nutrients like proteins, fats, and carbohydrates. These nutrients are then absorbed into their bloodstream.
2. Respiration:
* Oxygen: Like all animals, salmon need oxygen to survive. They obtain this oxygen from the water through their gills.
* Cellular Respiration: The nutrients from food are then used in a process called cellular respiration, which occurs within the cells. This process combines oxygen with the nutrients to produce energy in the form of ATP (adenosine triphosphate). This energy is used for various bodily functions, such as swimming, growth, and reproduction.
3. Energy Storage:
* Salmon can store excess energy as fat, which they can use for long periods, particularly during their challenging migrations.
Salmon and Energy During Migration:
* Upstream Journey: One of the most remarkable feats of salmon is their upstream migration to spawn. This journey is incredibly demanding, requiring immense amounts of energy. They rely on stored fat reserves from their feeding grounds to fuel their journey.
* Anadromous Species: Salmon are anadromous, meaning they migrate from saltwater to freshwater to spawn. This shift in environment requires further energy expenditure as they adapt to different water salinities and temperatures.
In summary, salmon obtain energy from the food they eat, which is then converted into usable energy through cellular respiration. This energy is crucial for all their bodily functions, including their epic migration journeys.