You'll find your answers here.
http://en.wikipedia.org/wiki/Sponge
Under what conditions does asexual reproduction in sponges occur? Does it depend on time of year, availability of food, or other factors?
3 answers
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."
"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."