Breaching on the horizon first captured our attention as we moved towards two pods communicating The Language of the Whales™ towards each other in fantastic fashion. Launching themselves skyward we could sight the resulting whitewater splash even when further away and as we neared the two younger juvenile whales appeared to be deterring the attention of the secondary pod. A spectacular barrel role breach was sighted as these two juveniles traveled together in the waters off Rottnest Island and as we observed their communication the fascinating story of the Humpback Whale barnacle was being captured on our photographs of the day to tell us a little bit more about these Humpbacks.
Coronula diadema which is a species of Acorn Barnacle and usually referred to as the Humpback Whale barnacle have a fascinating life cycle. Beginning their journey as larvae floating in the warmer waters of Western Australia they are attracted to the “smell” of Humpback Whales where they will land on the skin of a whale and wonder around, checking things out and looking for the best realestate. High water flow areas are ideal as it will ensure you are closest to the food source as a hungry Acorn Barnacle and the flukes, pectoral fins and dorsal area are all fantastic locations. Once a suitable place is found the tiny larvae anchor down and cement themselves onto the skin of the Humpback creating a fortress of hard shell that will protect them over their approx one year lifespan.
They will feed on the tiny plankton and other food particles that the whales swim through while migrating and feeding resulting in a very fast growing barnacle. Around this time next year though the party is over as the now very large adult barnacle has produced eggs/larvae of their own that will be released in the warmer northern waters and the next generation of Coronula Diadema eagerly await their lifetime host. Looking carefully at the images above of the juvenile Humpback we met today you can clearly see the old, circular scars that have been left by the adult barnacles and now the lighter yellow coloured juvenile barnacles settling into their new home… looks like a few more freeloaders for the next 12 months for these poor Humpbacks!