Barnacles are Reproducing

​Can you feel the magic! Barnacles are in the mood for love.
 
Barnacles are spawning in and around New York Harbor now. It usually occurs in mid- to late spring. Since barnacles are stationary or sessile aquatic creatures, they can’t really swim around looking for a mate. This is why barnacles live in groups. They mate with a neighbor.
 
All barnacles are hermaphrodites; both male and female at the same time. But only one individual cross-fertilizes with another individual. 
 
A sperm tube or a penis extends from one barnacle into a neighboring barnacle to fertilize eggs. Once the eggs hatch, a barnacle releases tiny larvae into the water in the spring when there is enough food or plankton for tiny barnacles to feed. After a few days floating around and looking for a good surface to settle, tiny barnacle larvae will eventually attach themselves to a hard surface using a cement-like substance secreted from a unique internal gland. Within 12 hours of attachment, larvae develop white shell plates or cones and become a mature barnacle. A complex and pretty amazing life cycle mostly unknown to the general public. 

Barnacle larvae

​While there are different species of barnacles, the most common in New York Harbor is most likely the Atlantic acorn barnacle (Semibalanus balanoides), also known as the Northern rock barnacle. But there are certainly others like the Little Gray barnacle. 
 
You probably see barnacles every time you visit the edge of the estuary and didn’t even know it. They live on rocks, reefs, jetties, pilings, boat hulls and other hard surfaces, and even on other living organisms like whales and horseshoe crabs.
 
Barnacles are small, grayish-white crustaceans that live throughout New York Harbor. They might not look like much, but barnacles are actually related to crabs, lobsters, and shrimp.
 
Barnacles are an important part of the harbor’s complex aquatic food web. The main predators of barnacles are marine snails, including whelks, but also crabs, sea stars, fish, and even humans. The New York Times reported in 2001 that barnacles were becoming an increasingly familiar item on the menus of high-end restaurants. Most likely goose barnacles, which is the only real edible species of barnacle for people.
 
Barnacles in turn are filter feeders. During high tide, these petite crustaceans will open their shells to release feathery appendages that collect and sweep in tiny food particles such as plankton and detritus. In their own small way, barnacles help to keep bay waters healthy. 

Read more about the amazing way barnacles reproduce here