Under what conditions does asexual reproduction in sponges occur? Does it depend on time of year, availability of food, or other factors?

3 answers

You'll find your answers here.

http://en.wikipedia.org/wiki/Sponge
sorry, this link does not answer these specific questions!
Did you miss this sentence?

"Gemmules are "survival pods" which a few marine sponges and many freshwater species produce by the thousands when dying and which some, mainly freshwater species, regularly produce in autumn."