We all have these sponges growing in our sumps, I thought I'd show what they are made up of.
The tissue is held together by spicules, tiny calcareous/siliceous structures that provide rigidity to the sponge. Here they are under DIC illumination. Each spicule is about 170µm in diameter.
20120904-DSLR_IMG_0309-Edit.jpg by pwnell, on Flickr
Under polarised illumination using a lambda plate, the spicules show their true colours. The minerals that form the spicules have internal structure that is visible in this picture below as it scatters the light in different wavelengths.
The tissue is held together by spicules, tiny calcareous/siliceous structures that provide rigidity to the sponge. Here they are under DIC illumination. Each spicule is about 170µm in diameter.
20120904-DSLR_IMG_0309-Edit.jpg by pwnell, on Flickr
Under polarised illumination using a lambda plate, the spicules show their true colours. The minerals that form the spicules have internal structure that is visible in this picture below as it scatters the light in different wavelengths.