Congers are a type of nocturnal marine eel that live in warm-water oceans. They have a snakelike body, long dorsal fin, and sharp teeth, and resemble an ordinary eel. Congers live in the Adriatic, Mediterranean areas, and North African coastal areas and throughout the English Channel, North Sea, and Irish Sea areas. American congers live along the continental shelf from Maine in North America to South America. The fish breed once in their lifetime and then they die — the congers' population has been declining since the 1980s.
They belong to the family Congridae and genus Conger, and there are more than 150 different species of congers. The size depends upon its species. For example, California congers have a maximum length of 24 inches (0.6 meters), but other congers can measure 5 to 9 feet (1.5 to 2.7 meters) and weigh more than 100 pounds (45 kg).
Congers have a chameleon-like ability to adapt their coloring to their habitation as well. In rocky areas or around sunken ships, the eel's back is dark gray and the underside is pale gray. In sandy areas, the back is a light gray-brown and the underside is cream colored.
The conger may look like an ordinary eel, but there are differences. For example, the conger's dorsal fin begins at the pectoral fins and runs the length of its body. By contrast, an ordinary eel's dorsal fin begins well back from its pectoral fins. The facial features are also different. Congers have large, oval eyes whereas common eels have smaller, round eyes.
This carnivorous fish has a voracious appetite and feeds on anything smaller than itself. Because they are nocturnal, they often prey upon sleeping sea animals. Their diet includes a wide variety of sea creatures, dead fish, and even small congers.
The mystery surrounding congers is their breeding cycle. Atlantic Ocean congers migrate from the shallower coastal waters to spawn in the deeper waters of the Sargasso Sea. The Sargasso Sea is a region in the North Atlantic Ocean, surrounded by four strong ocean currents. These strong currents are important for dispersing the newly-hatched larvae. Pacific Ocean congers also use currents, such as the Kuroshio Current, to carry the larvae to their proper habitats in Eastern Asia. Before spawning, the conger undergoes several changes. Its head shape changes; it loses its teeth; and its bones begin to jellify. The male's eyes enlarge, their stomachs dissolve and they live on stored energy during their migration to the breeding area.
Marine biologists estimate each female produces up to ten million eggs. After the eggs hatch, the leptocephali, or eel larvae, drift on the currents for up to two years before reaching shore. In this leptocephalus stage, the eels' ribbon-like bodies are transparent. At the shore, they metamorphose into young eels. The eels get their full coloring when they are about 12 inches (about 0.3 meters) long.
Congers have exceptionally sharp teeth and strong jaws; therefore, conger fishermen use heavy-duty monofilament or wire line. Congers can live for a long time out of water and many anglers have lost fingers while handling these vicious fighters. Anglers can contact fishing clubs, such as the British Conger Club, for more information.
