Humpback and Barnacle

 

Humpback and Barnacle, linocut, 8" x 8" by Ele Willoughby, 2024

This month is parasite month for #InsertAnInvert2024, so I have been kind of dancing around the prompts and choosing somewhat different species than those suggested, cause, to be quite honest, some of these inverts give me the creeps. For the first two prompts I chose plant rather than animal parasites and reposted art I had previously made: the Dropsophila (fruit fly) and carmine prints. For the third week a shark barnacle was a suggested species, but I decided to look at the whale barnacles.

This hand-printed lino block print with gel plate printed areas is about Coronula diadema, a barnacle which specializes in humpback and some other baleen whales. Each print is 20.3 cm x 20.3 cm (8" x 8") on lovely Japanese mulberry paper and shows the humpback whale swimming above and a close up of the whale below with six barnacles.

The Coronula diadema name comes from its barrel and crown-like shape, which can grow to 5 cm (2") tall and 6 cm (2.4") in diameter. They are common to abundant on humpback whales. Barnacles are actually crustaceans, and C. diadema has 6 plates and a hexagonal opening on top, protected with a pair of opercular valves. The hermaphrodite parasites cluster together in order to breed. The barnacles use the whales as host, and the whales may in turn use the barnacles as a sort of armour and to inflict more damage when fighting in mating battles or against predators. So theirs is a likely a mutually beneficial relationship and are considered commensals.