dragon eels are a species of eel
Dragons are afraid of eels because the eels give them a sickness just like those flowers that are poisonous to dragons. In defenders of berk toothless eats an eel and he cant see starts shooting red plasma randomly and doesn't even know hiccup. So in my theory dragons get sick when they eat eels that is why they are afraid if them.
I'd assume it's because in the books the movie is based off of that huge dragon "Red Death" is actually a sea dragon, they look eel-like and since they are one of the most feared species the other Dragons dislike anything that would remind them of that threat!
The types of eels are salt water eels, freshwater eels, the swamp eels, rubber eels and the electric eels. It is an elongated fish that lives in the shallow waters.
We do not know as eels do not leave good fossils. Also your English is a bit wrong your question should be worded "How many extinct eels were there". This is because if they are extinct they would have lived in the past not the present.
Adult eels are called eels, babies are elvers
in eels
electric eels have an electric current that shocks thing Moray eels dont
eels eat fish
Eels have electricity.
Eels are classified as fish!
Eels are not naturally in Utah's bodies of water but there are eels in pet shops and aquariums.
EEls only eat flies if they are green eels, otherwise they ae very dangerous to eels and may kill the eel :(