Eels feed on many species of animals. Scientists who study the composition of the food content of these fish get slightly different results each time. The surprise is this, that no trace of fish roe was found in the stomachs of the eels.
Eels are usually caught on worms or small dead fish and only a few fishing techniques allow them to be effectively hunted.. The eel menu is very varied, thanks to, with a little ingenuity, they can be deliberately caught on almost any meat bait… Eels are benthic fish, so they usually look for food near the bottom. They are active mainly at night, especially in the warmer months, that is from April to October. Late fall, when the water temperature drops below 10-12 degrees, they are clearly losing their appetite and falling into a kind of winter numbness. Unlike other benthic fish, eat relatively few bloodworm larvae. Only two English scientists have occasionally found larger numbers of bloodworms and other fly larvae in the stomachs of eels (do 50 percentage of the chyme content). On the other hand, the larvae of the mayflies and casseroles constitute a very serious item on the eel menu. Sometimes these little animals constitute even from 30 do 40 percentage of their food. Overall you can say, that eels eat insect larvae most often in spring and early summer.
All studies show, that they are deliberately not looking for higher developed small crustaceans.
However, it happens anyway, that in some body of water, gusks and donkeys are the main food of adult eels. Although in rivers, mollusks are not the favorite food of eels, in lakes, snails and small clams are often a very important food source.
Fairy tales about eating fish eggs?
Food competition of eels with other fish species, and in particular with salmonids, has been the subject of many articles for a very long time.
They were constantly presented in these studies (and introduces himself) eel as an extremely voracious predator, even then, when food competition with salmonids could not be proven in any way. Eels devour huge amounts of trout fry, as reported by many authors, seems unlikely. English scholars have studied 4340 Eels from sixteen rivers, and only ten of them found small trout in their stomachs.
Research by other scientists shows, that sometimes trout make up only one percent of the food eaten by eels.
The main food of the fish
Eels, on the other hand, show a particular liking for eating bullheads and rose hips. In addition, the phenomenon of cannibalism is also often observed in them. English researchers found the remains of digestive fish of the same species in three percent of the eels tested. You can also say very generally, that fish are the main food of eels over 40 centimeters. Fish remains were found in the stomachs of more than a quarter of the eels studied. According to some scientists, eels eat fish very sporadically, according to still others – hardly ever. They also eat the roe. One Danish ichthyobiologist found, for example, that spawns up 7 percentage of total food ingested by the eels, and in individual cases even half.
Eels eat their roe mainly in winter and spring, however, this food is of little importance to them. They are very few freshwater fish, hunting
on river crayfish, which in the watercourses and in these lakes, where they are abundant, they are a very important component of their food. Some meticulous scientists have also found amazing amounts of plankton in the stomachs of eels. There is no wonder, however, since anglers were already finding frogs and chicks in the stomachs of these fish.
Eels eat everything, what they can get. However, French research shows, that fish and roe are not a very important food component of eels. Eels eat the most insects in rivers, while in the lakes, mainly snails and mussels. More than tested 2 thousands of river eels (upper beam) and almost 200 lake eels (bottom beam). These numbers mean, in how many percent of the tested fish were found in the stomach at least one specimen of the catch in question.