BIOL 2030 Lecture Notes - Lecture 6: Gemmule, Ectoderm, Osculum
Document Summary
Fragmentation: sponge starts to spread out at the base ( attens); at marginal edges, bumps form which give rise to new individuals: bumps attach to substrate where they are formed; resulting in parent and new individuals formed. Budding: small piece of sponge is released and that piece settles down and forms new individuals. !1 (micropyle) (capsule) (cluster of archeocytes: spicules known as microsclere, cells emerge out of micropyle; as archaeocytes, they can differentiate into other cell types. Elusive processes because no speci c reproductive structures: sponges of demospongiae are most studied. Viviparous sponges: sperm formed from choanocytes (spermatocysts = special agellated chamber, eggs formed from archaeocytes (sometimes choanocytes), distributed throughout mesohyl, parenchymula: agellated larvae, monoecious: one individual has male and female cells. Associated with viviparous strategy; means that fertilization will occur inside parent body and most of the early development of the embryo occurs inside the parent body, and then at a certain stage it will be released.
