Feeding

Different fish have different feeding patterns :Different fish have different feeding patterns and so live at different places in the water.At the bottom of the water we find the grazers, such as carp, that root on the bottom searching for food. In the mid-water depths we find the browsers such as kurper and certain species of yellowfish that cruise through the water looking for anything to feed on.Higher up in the water we find the predators, namely fish that actively prey on smaller fish, insects and so on, such as yellowfish and bass. The catfish is a generally a bottom feeder but is also a fierce predator.At different times of the year all fish will change their feeding habits according to where they can find food. That is why the carp, for example, which is generally regarded as a bottom feeder, will sometimes be seen cruising just below the surface sucking in mouthfuls of tiny creatures called daphnia.Or catfish gathering in shoals to herd tiny fish into bays where they are easily caught and eaten.The availability of food is a key factor in finding fish. Look into the water and you will see that the deeper the water the less sunlight there is. Sunlight is necessary for the growth of weeds and other plants in the water. Plants are necessary for a healthy fish habitat because they do three things: they supply a continuous supply of oxygen into the water, provide a home for the many thousands of tiny creatures that are food to all species of fish, and also provide fish with a breeding and hiding place.To become a successful angler, always study the water in which you are going to fish. How deep is it? Where is the vegetation? Where should the fish be, and why? A good plan is to carry a notebook on every fishing outing. In it you note the date, weather condition (sunny, cloudy, windy, cold, hot and so on), where you caught the fish and with what bait. This will provide a valuable reference for future outings.

Relative importance of interlinked mangroves and seagrass beds as feeding habitats for juvenile reef fish on a Caribbean island:

Mangroves and seagrass beds are important daytime shelter habitats for juvenile Caribbean reef fish species, but little is known about their relative importance as feeding grounds. In the present study, we tested the degree to which these 2 habitats are used as a feeding ground for 4 nocturnally active fish species on Curaçao, Netherlands Antilles. Stable isotope analysis was used as a technique to distinguish between feeding in mangroves and seagrass beds. Individuals of the 4 species which were sheltering during the daytime in permanently inundated fringing mangroves subject to low tidal exchange showed a stable carbon isotope signature indicative of a mixed diet composed of crustaceans from mangroves as well as seagrass beds, with the contribution from mangrove food items lying between 57 and 92%. However, individuals of the same species sheltering on adjacent (<50 m distance) seagrass beds during the daytime showed a carbon signature indicative of almost exclusive feeding on seagrass beds. This indicates that 2 different subpopulations probably exist for the 4 species studied: a population of fishes sheltering in mangroves during the daytime and feeding primarily in the mangroves and secondarily in the seagrass beds at night, and a population of fishes of the same species sheltering in adjacent seagrass beds during the daytime and feeding primarily in seagrass beds at night.

How Fish Metabolism Works :

“Metabolism” is the word used to cover the system of chemical processes that keep something alive. For a fish, that means providing energy to power critical body processes or building and maintaining the body parts needed to function.
Metabolism itself relies on three main things:

1. Respiration and nutrition to supply metabolites (the products it uses, built out of both inorganic and organic matter)
2. Osmoregulation for a stable working environment
3. Excretion to get rid of all the poisons and other waste products produced as side-effects

In fishes, the metabolism covers two processes:
Metabolism can be described as the collective term for the chemical processes that give life. Metabolism uses products called metabolites that include organic food and inorganic matter such as oxygen. Metabolism is linked to all of the other body processes by providing energy, or by building and maintaining the structures necessary for them to function.
catabolism and anabolism. Catabolism is the process of breaking down metabolites to produce active energy, while anabolism uses those same products to build new body tissue for growth, maintenance, and reproduction.
There are two types of metabolism. Catabolism (pronounced ca-tab-o-lism) breaks down the metabolites that produce energy for activity. This process releases energy by breaking down complex molecules into simpler ones. Catabolism is also known as destructive metabolism. Anabolism (pronounced a-nab-o-lism) uses metabolites to build new tissue for healing, growth and reproduction. This process uses energy to construct complex molecules from simpler ones. Anabolism is also known as constructive metabolism.
There are many similarities in fish metabolism and energy usage to that of other animals. Some aspects are unique to animals that spend their lives "under the sea". After all, they are depended on water for locomotion, respiration, maintaining body temperature and blood chemistry among other things. Understanding energy metabolism and the factors that influence it is crucial to stress management and handling of fish.
Energy metabolism that uses oxygen is called aerobic metabolism. Aerobic metabolism is highly efficient and sustainable. Anaerobic metabolism does not require oxygen and it quickly depletes energy reserves in the cell. Anaerobic metabolism occurs in situations that require sudden bursts of energy such as escaping a predator. Anaerobic metabolism is not sustainable. Fish need a continual, sufficient supply of oxygen to balance energy supply with demand.
Energy intake from food falls into three categories. Gross Energy or GE is the total energy released by food as measured with a calorimeter. Food can contain a high level of GE and still not have nutritional value to an animal if that food is not in a form that the animal can digest and utilize. The Digestible Energy or the DE of food is the amount that is utilized and digested, minus the portion that ends up in the feces. In fish, some DE is lost through the urine and across the gill membranes. The remaining energy actually used by the animal is the Metabolizable Energy or ME.
Removing and/or reducing all sources of stress is essential to how fish utilize their energy. Stress can disturb the normal physiological equilibrium or homeostasis of the animal by forcing a reallocation of energy within its system. Any response or adaptation to stress requires energy that could otherwise be utilized for maintaining normal body functions such as growth, digestion, disease resistance, healing and reproduction (Barton & Iwama, 1991).

Conclusion: There are many similarities in fish metabolism and energy usage to that of other animals. Some aspects are unique to animals that spend their lives "under the sea". After all, they are depended on water for locomotion, respiration, maintaining body temperature and blood chemistry among other things. Understanding energy metabolism and the factors that influence it is crucial to stress management and handling of fish.