animalworld:

BLUE BELL TUNICATE COLONY
Clavelina moluccensis
©Nick Hobgood

While they look like vacuum cleaner hoses, they are actually tunicates or sea squirts and not man-made trash.

Bluebell tunicate, blue bell tunicate, or Blue Sea Squirt, is a species of tunicate (sea squirt), in the genus Clavelina (the “little bottles”). Like all ascidians, these sessile animals are filter feeders.

This species is 0.5-2.5 cm long, and light to medium blue in colour. The top of the zooids contain characteristic dark blue patches and spots that are always visible

This species is found in the waters around Australia, Western Pacific, Indonesia, Papua New Guinea, Mariana Islands, Philippines, Singapore, and Malaysia.

This species grows in clusters attached to dead coral or other hard substrates, normally under overhangs. 

Tunicate blood is particularly interesting. It contains high concentrations of the transition metal vanadium and vanadium-associated proteins as well as higher than usual levels of lithium. Some tunicates can concentrate vanadium up to a level one million times that of the surrounding seawater. Specialized cells can concentrate heavy metals, which are then deposited in the tunic. Source

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