At the enormous Plymouth Aquarium, located in the centre for Marine Biology in Britain, amongst the more mundane fish of the Plymouth Ocean exhibit there lies a mighty monster of a fish, a huge Conger Eel. This colossal tail is only half of the eel’s actual size, and while it is hard to see in perspective, the largest of these species can reach lengths of up to two metres and 100kg. This European Conger, or Conger Conger in Latin, are therefore the largest type of eel in the world, although the moray eels are nearly as long. Normally grey in colour with a white underbelly and darker snouts, the females will tend to be far larger than the males, often up to half a metre longer. They live across the east Atlantic from Scandinavia to North Africa and will also live in most of the Mediterranean ocean, where they are commonly seen in the shallows. They can live up to enormous depths such as 1000m but are also seen making their pits in shallower waters, such as the Plymouth Harbour.
Like the eel seen above, Congers live much in the same way as any other eel, nesting in eel ‘pits’ in crevasses in the rocks, often with groups of other eels. It has even been known for morays and congers to share the same pit. Being mainly nocturnal, they well stay in their pit for most of the day, coming out at night to hunt and scavenge. Congers will eat large fish, crabs, lobsters and octopuses that they catch, as well as eating any decaying carcasses that they may find. They have sharp teeth to grab their food with, but are not considered especially aggressive, despite their intimidating size.
During the breeding season, the European Conger’s body goes through a massive change, the skin becoming softer and the teeth dropping out of the mouth. Then, a huge migration begins, taking the eels out of cold European waters and into the sub-tropics of the Atlantic, such as the famous Sargasso Sea. The Sargasso is a large gyre by the Gulf of Mexico which is known for its role in the lives of European and American Eels. The sea is sometimes said to be thick with eels, almost as though you could walk out onto them. While this is somewhat an exaggeration, it is certainly true that a huge number of eels exist at one time in that ocean, with each female Conger producing several million larvae.
Large and astounding, and yet so close to home, I hope that I can see some of these eels in the Atlantic and Mediterranean in the future. It was a shame that the eel at Plymouth Aquarium didn’t feel inclined to show themselves while I was there, but then again, it was during the day. They were probably quite sleepy.