Current Events Lesson Plan: February 16-22, 2017
Current Event: Long-Traveling Amazon Catfish
Scientists recently learned that the dorado catfish (also known as the dourada or gilded catfish) of South America has the longest migration of any freshwater fish. These large catfish live in the Amazon River Basin, and their migratory path takes them from the foothills of the Andes Mountains to the mouth of the Amazon River on the Atlantic Ocean, and then back again—a trip of more than 7,200 miles (11,600 kilometers)! The dorado catfish is just one of several species of catfish that live in the Amazon River and its many tributaries. Dorados can grow beyond 6 feet (2 meters) in length and are grouped with other “goliath” catfish, so named because of their large proportions. Their lengthy migration has long been suspected, but only recently have the details of their epic migratory journey been confirmed.
The long-traveling dorado catfish navigates the waters of the Amazon River Basin throughout its life. Credit: © Michael Goulding, Wildlife Conservation Society
Objective:
Catfish is a large group of fish that have two to four pairs of fleshy whiskerlike growths near the mouth. These growths, called barbels, resemble the whiskers of a cat. Catfish also differ from most other fish in that they do not have scales. Many kinds of catfish have sharp spines on their backs and near their gills. These spines give off a venom when they enter the body of another animal and can cause serious wounds. They are probably used mainly as a defense against predators. There are hundreds of species of catfish. Most live in fresh water and some inhabit the oceans. Catfish vary in size. The largest species, the Mekong giant catfish, may grow up to 10 feet (3 meters) long and may weigh as much as 650 pounds (295 kilograms). The tiny glass catfish grows only 4 inches (10 centimeters) long. Some kinds of catfish have unusual features or habits. The upside-down catfish swims upside down. The electric catfish can send out a strong electric shock. The eelcat is long and slim and resembles an eel. The candiru swims into the gills of larger fish, rips the gills with its sharp spines, and drinks the victim’s blood. The walking catfish of tropical Asia can move overland from one body of water to another. It pushes itself along the ground with its tail, using its strong pectoral fins (fins behind the gill openings) to lift the front of its body. The Behind the Headlines news story and related World Book articles explore catfish and other animals.
Words to know:
Discussion Topics:
1. Ask your students to name other animals, besides catfish, that start with the letter “C”. (Students might say camels, cardinals, caribou, carp, cats, caterpillars, cattle, centipedes, chameleons, cheetahs, chickens, chimpanzees, clams, cobras, cockroaches, cougars, coyotes, crabs, crocodiles, crows.)
2. The dorado catfish travels thousands of miles. Ask your students, “If you could travel anywhere in the world, where would you go and why?
3. Ask your students to use World Book’s Timelines feature to view or add to the History of Latin America timeline. (Students may wish to use World Book’s “Latin America” article for help.)
