Yellow boring sponge is a common sponge, of which you usually only can
see the in- and out-let openings (ostium and osculum). The osculum is a bit higher
and larger than the ostium. Because they are close to each other, this is clearly
visible. The animal drills itself into calcareous stone or shells. The drilling
is done by acid secretion, that dissolves the stone or shell.
The osculum can reach a height of 20 mm and a width of 10 mm. The ostium is flatter
and can reach a width of 6mm. Occasionally it can grow to be a massive lump.
Usually yellow, yellow-green or orange.
From the shallow coastal waters, up to a depth of 300 metres.
Almost the entire north Atlantic.