The barnacles and whales share a commensal relationship. Charles Darwin. Ring a bell? He was known to be a major contributor to the research of the lives of these barnacles (Cirripedia). In the earlier years, the Cirripedia was classified in the same category as crustaceans because of their outer shell. However, a major difference that was found that put the Cirripedia in a different category was its hermaphroditism characteristic (1). They are known to be invertebrates, meaning a host is essential to travel. The barnacles attach themselves to the whales as the whales make their way across the sea for nutrients and new habitats. These hermaphrodites consist of six free-swimming plankton naupliar stages (4). Even though the barnacle eggs can self fertilize, it is more likely for another barnacle to fertilize it. However, it is as adults when they are able to attach to the hosts for an adventure around the sea (2).
In the life cycle of the barnacle, the last larval stage is known as the cyprid stage. This is the stage before it goes into its adult stage. As adults, the barnacles have “six pairs of feathery thoracic limbs” (4), which helps them grab their food and nutrients while being attached to the whales and traveling under the sea. They produce a "sticky cement" which helps the barnacle stay on the whale without falling off, under the ocean. At first, they attach anywhere on the whale, but then they find their way around particularly near the nostrils or fin, where water is easily accessible (3).