The voyage of the Challenger (1st of 3)

The voyage of the Challenger (1st of 3)

This drawing is of a huge Hexactinellida or glass sponge, Poliopogon gigas, which was trawled from a depth of 1,150 metres near the Kermadec Islands during the Challenger voyage. It was 70 centimetres across at its widest, and had a lattice outer layer. The centre was a 20-centimetre cavity known as a paragaster, where water collects after passing through small canals to filter out food. In the specimen depicted here the osculum or top opening was damaged.