Azure Vase Sponge

• Its iridescent blue is not a pigment but an optical effect of the structure of its surface, and it vanishes the moment the animal is taken out of the water.
• A sponge of this size filters several thousand litres of water a day, which makes it an essential purifier of the reef.
• Its body hosts enormous communities of symbiotic bacteria, which can account for a good part of its mass and from which compounds of pharmacological interest are extracted.
• Its electric blue underwater is not pigment but fluorescence: it absorbs short-wavelength light and re-emits it as blue and green, which makes it stand out in the dimness of the reef.
• It filters enormous volumes of water. A sponge this size can process thousands of litres a day, capturing bacteria and particles that no other animal on the reef makes use of.
• That role is central to the so-called sponge loop: it turns dissolved organic matter, useless to almost everything, into detritus that does feed other reef animals.
• It has no true organs or tissues. Water enters through minute pores, passes through chambers lined with flagellated cells and leaves by the opening at the top, the osculum.

Habitat & environment

Caribbean reefs and walls, from 3 to 50 m

Sources consulted: Lamarck (1814); de Goeij et al. (2013), Science; Smithsonian Marine Station