سؤال قراءة ستيب محلول — فهم التفاصيل (تدريب 7210)

(1) Some estimates report the world’s oceans are home to 20,000 species of fish. Ocean fish come in all shapes, sizes, and colors and live in drastically different depths and temperatures. Two of the most commonly known fish are tuna and salmon. (2) Salmon are fish that are known for making long, difficult journeys in order to breed. Salmon belongs to the scientific family Salmonidae, which also includes trout. There is one species, or type, of Atlantic salmon. There are six species of Pacific salmon: coho, chum, king, pink, sockeye, and cherry. (3) Tuna are large fish that live in most parts of the world’s oceans. They belong to the same family of fish as mackerel. Tuna is one of the most popular foods that comes from the sea. Most of the tuna that fishers catch is canned. There are seven different species, or types, of tuna: bluefin, albacore, yellowfin, bigeye, blackfin, longtail, and southern bluefin. The skipjack tuna is related to these species, but it belongs to a separate group of fish. (4) The Atlantic salmon lives mainly in the North Atlantic Ocean. It breeds in the rivers of North America and Europe. Pacific salmon are found in the waters of the North Pacific. They breed in rivers near both the North American and Asian coasts. (5) Salmon come in a range of sizes. The Atlantic salmon weighs about 12 pounds (5.5 kilograms). The pink salmon usually weighs 3 to 6 pounds (1.4 to 2.7 kilograms). The king salmon may weigh 25 pounds (11 kilograms) or more. While in the ocean, salmon have a silver color and spots on their back and fins. During the breeding season, they undergo changes in color that vary by species. (6) A tuna has a long, rounded body. It is usually dark on top and silvery underneath. Some species have spots or stripes. Unlike other types of fish, a tuna can keep its body warmer than the temperature of the surrounding water. Many species of tuna are about 35 inches (90 centimeters) long. The bluefin tuna is the largest species. It can grow as long as 14 feet (4 meters) and weigh up to 1,800 pounds (800 kilograms). (7) After being born in fresh water, salmon travel to the ocean. They live there for one to three years. Then they travel back to where they hatched in order to breed. For some salmon, this can mean a trip of more than 2,000 miles (3,200 kilometers). Salmon may leap over waterfalls and cut through churning rapids to reach their home waters again. Once in fresh water, salmon stop eating and live off their body fat. The males fight for a mate. After a male and a female are paired, the female digs a pit and lays thousands of eggs. Most Pacific salmon die shortly after mating. Many Atlantic salmon, however, return to the sea and may breed again. (8)Tuna travel in large groups called schools. Some species travel long distances. Tuna feed on other fish, including herring, menhaden, and mackerel. Some species also eat small, spineless animals such as squid. Some types of tuna return to the waters where they hatched to spawn, or produce eggs. How many types of Atlantic salmon are there?