Congresbury were very excited last week to receive their very special guests who are
going to be living with them for the next few weeks - 120 glass eels!
Each class learnt about eel ‘husbandry’ and what to check for every day in the tank to
make sure that the eels are living in a healthy environment, how much food to give them
and how to keep the tank clean.
We then went on to match up pictures to display the eel’s life cycle - its fascinating and
mysterious stages of development - and to make sure we matched the correct terminology
and definitions to describe those stages. Even the correct word for the larval stage which
is ‘leptocephalus’! We also discovered the myriad of problems that eels face throughout
their life cycle - from encountering impassable flood defences on their way upstream to
being eaten by a hungry otter, or even caught by a keen fisherman in a special ‘glass eel
net’.
Then it was outside to try to get some (pretend) elvers from one end of the ‘river’ to the other. This was only possible if the elvers could escape the hungry heron, navigate the
natural boulders in the river, swim against the current and get past the lock gate. Luckily
the majority of them made it which is what we would hope happens in real life.
Unfortunately though, real elvers might find it a lot more difficult to reach the lake where
they can mature into adults and spend most of their adult life stage.
Back inside, we acted out being part of a freshwater food chain and thought about where
an adult eel and a glass eel could be in that food chain. We discovered that it wasn’t
always as simple as it seemed. And to see how food chains turn into food webs we chose
some saltwater food chains to join together to create a saltwater food web.
Next week we will see how the glass eels have progressed - have they become more
pigmented; have they grown; have they formed any interesting habits? We’ll keep you
posted. We’ll also be learning all about the water on our planet and how we have to look
after it.