How long can a river eel in captivity survive ?

The backyard as laboratory and workshop (2)
The case of a river eel that has survived confinement subsisting only on algae for three long years - and going.~   
Dr Abe V Rotor

Come rainy season and the rivers are abundant with freshwater eels. It's their breeding season and soon the tiny glass (transparent) eels take the characteristic shape and form of the common eel - elongated like snake, and slimy to catch which is true to its vernacular name, palos, a term given to a person who can evade capture and escape from confinement.

That is why of the half a dozen eels Celing, who lives near a creek, gave us, only this one in the photo survives to this day after three years of captivity in a glass aquarium. What I found about the river eel may not be found in the books.
1. River eels are extremely shy, they seldom get out of their dark hiding place, especially during the day. They hang up on guard now and then and retreat at the slightest disturbance.

2. Gregariousness is incidental to their confinement, given freedom they move separately on their own.

3. They are not the voracious predators as claimed. Sword tails and guppies live for sometime with them in the same aquarium.

4.River eels do not eat commercial feeds, bread or meat. They subsist only on algae or lumot growing on limestone, and on the bottom and sides of the aquarium. That's why sunlight is very important for the algae to produce biomass and oxygen which are vital to life. 

5. The limestone rock (CaO), releases calcium to neutralize acidity of the water, while its crevices provide an abode to the eels, hiding them from view and light. 
  
6. They don't need aerator or filter.  Simply add water to maintain water level. Excess algae and accumulated detritus however, must be removed as necessary. 

We kids in our time believed in a huge eel hiding below an overhanging kamatchile tree along the Bantaoay river in our hometown.  "Don't go near its cave!" We were warned every time we go fishing. Well, I grew up with this rich imagination and never saw themonster.

Then in the early sixties, a huge eel was caught in a flood tunnel under the Public Market in Sampaloc. It must have come from the fish market and grew up with plenty of food from the wet market.

It was then that I connected the two giant eels -  the one in my childhood, and the one twenty years after. Tales are true after all.

And I am adding to this tale the fact that here is a eel that has survived in confinement subsisting on algae alone for three long years - and going.~   

Giant mottled eel.  Angler Seishi Hagihara (Sulawesi Island, Indonesia ) with a Giant Mottled Eel (Anguilla marmorata) caught in Poso Lake.

Maori legendary eel, New Zealand; giant eel lurking from its nest (Australian Museum). Acknowledgement: Internet Images,Wikipedia for photos.