What are ephippia?

[Tiggrx]

I found a huge colony of fat duckweed today and brought some home to study.

Amongst the duckweed I kept finding what looked like tiny seed cases with two seeds in each (you can see 4 of them in this picture)



After some investigation I have discovered that they are the ephippia of Water-fleas (Daphnia), but am not entirely clear what exactly they are/are for - help!

Thanks
Aaron

[NickCantle]

Hey Aaron,

I've just had a look online. Ephippia is the plural word for ephippium of which the definition follows;

"a thick shell, consisting of two chitinous plates, that encloses and protects the winter eggs of a cladoceran."

Sorted!

[Tiggrx]

Originally Posted by NickCantle

Hey Aaron,

I've just had a look online. Ephippia is the plural word for ephippium of which the definition follows;



Sorted!

Thanks Nick,

so why would I be finding winter eggs in July - or do they just stay like that all winter.
I have hundreds of the things in the small sample I took - I could start a Daphnia farm

[Lancashire Lad]

Cladocerans usually bear live young, but are capable of producing eggs, sometimes called winter eggs, which are useful if the conditions aren't likely to remain stable. i.e. overwintering, or if the pond is drying out.

Regards,
Mike.

EDIT - I should also imagine this would also be a good way of colonising other water bodies, as these eggs may be transported by birds, or on the feet of animals etc.

[NickCantle]

Wow, that's a pretty interesting thing!

[Tiggrx]

Thanks for the answers guys - I might keep a few and see what happens with them

[NickCantle]

Sounds like a project Aaron! Keep us posted mate