a Gemmula from a marine sponge

[Franz Neidl]

The word Gemmula (a diminuitiv from latin gemma): a little bud.
Some marine sponges are forming gemmulae for their asexual propagation in form from resting stages.
I dont know the species from this sponge.
The outer diameter was 1200 µm and the diameter of the inner sphere was 250 µm.

First picture: Obj. 4x, brightfield
second picture: Obj.20x, DIC, stack with 4 pics.
third picture: Obj. 40x, DIC, stack 5 pics.

Franz