 The production of any animal crop involves multiple steps. Many of these steps are consistent among different species. These important steps involve all parts of the life cycle, including broodstock selection, controlling reproduction, egg care and management, larval rearing, feeding, maintaining water quality, harvesting, processing and transportation. Let's use the channeled catfish as an example to illustrate some of these steps. One of the keys to successful aquaculture production is the selection of good broodstock. These fish are selected based on traits considered most valuable to the species. These are prime examples of catfish broodstock showing strong secondary sex characteristics. You can see that the male in the top photo has the desired raised muscle pads on the top of his head and the female has a rounded belly full of eggs. Catfish like to spawn in sheltered locations so many farmers will put out spawning cans in 2-4 feet of water. The male catfish will find and prepare the can for spawning and try to attract a female. After several days, the farmers will check the spawning cans by slowly raising them out of the water. They will often find the male fish still in the can caring for the eggs. It's always a good idea to look into the can before putting your hand in it to check for eggs. If eggs are present, the farmer will gently remove them and transport them in water to the hatchery. In the hatchery, eggs are placed in baskets off with slowly rotating paddles. These paddles mimic the movement of the catfish's tail sweeping over the eggs to keep them clean and provide them with plenty of oxygen. As the eggs develop, they change from a light yellow color to a rusty red color. Inside the egg, the embryo develops until it's ready to hatch. When the eggs hatch, they have a large yolk sac attached that they can feed on for several days. Farmers need to know how many fry they have so they can accurately stock them into the ponds. Several samples of the fry are counted in weight. Using the sample data, the rest of the fry are counted either using volumetric displacement or by weight. Once counted, the sac fryer placed in a larger trough. Once the yolk sac is absorbed, the fish will begin to turn black and swim to the top looking for feed. At this point, they're called swim-up fry. They are fed four to eight times a day until they grow strong enough to put into the fingerling ponds. Once the fish are moved to a pond, they are fed a pelleted feed. The initial feed is very small and as the fish grows, the farmer will use larger and larger pellets. Feed is distributed across the pond's surface using a truck or tractor and a feed hopper with a blower. Many feed hoppers have an integrated scale and control box inside the truck so operators can manage and record how much feed is added to the pond. Distributing feed over a large area allows all sizes of fish equal access to the food. Catfish farmers may feed upwards of 100 pounds per acre per day during the summer months. That's a lot of nutrients going into the pond. Farmers have to closely monitor water quality to ensure optimum growing conditions. One of the most dynamic aspects of water quality is dissolved oxygen. Oxygen levels rise and fall during the day and tend to be their lowest just before sunrise. Sometimes mechanical aeration is used to increase dissolved oxygen levels. This electric paddle wheel aerator is designed to lift large quantities of water about two feet into the air and break it into small droplets. Breaking the water into small droplets creates a large surface area and makes it easy for the oxygen from the surrounding air to diffuse into the water. You can see that it creates quite a current that helps circulate the water and oxygen. Fish will often line up behind one of these aerators during a low oxygen event. After about 18 months, the fish reach a market size of about two pounds and are ready for harvest. The fish are harvested with a long net called a sane. As the tractor pulls the sane through the water, the fish are funneled into a smaller detachable box-shaped net called a live car. In this scene, farmers are testing a new sane that incorporates greater bars to allow the smaller fish to escape and reduces the number of fish that gets stuck in the net. The fish are allowed time to settle down and the smaller fish grade out before being loaded onto a truck for transport. Fish are lifted out of the live car and loaded onto a truck using a boom and basket. The fish are weighed with a scale connected to the boom and placed into a tank of water on the truck. The tanks are filled with chilled water and are supplied with oxygen to reduce stress on the fish and ensure that they arrive alive at the processing plant. Once the fish arrive at the processing plant, they're unloaded, weighed, sorted, and processed into a variety of product forms. Some of the fish is shipped out fresh, but the majority is individually quick frozen, weighed, and packaged for easy transport to distributors, restaurants, and seafood retailers. The entire process can take as little as 45 minutes. And eventually, the catfish makes its way to your plate in a lovely dish like this.