Then we go to the stalls with the collection of sponges, the primitive aqueous multicellular organisms. They have neither sense organs - eyes, nor ability to move and spent all their life fixed on the bottom.

Here one can see a glass sponge of striking beauty known as "Venus's Basket". The story of its relationship with small spongicola is quite interesting. Two spongicola, male and female, live in the cavity of almost every sponge. They get there at the larval stage and can not leave it later. These creatures spend all their life together, caged in the sponge cavity.

In Japan, where the species called "Venus's Basket" inhabit, there is an old tradition to present a sponge with two spongicola for wedding as a symbol of eternal love and conjugal faithfulness. The exhibition also shows a soft skeleton of toilet sponge, which has been used by people for washing since ancient times.