Barnacle Facts

Barnacle Facts
Barnacle is a type of sea invertebrate that belongs to the phylum Arthropoda. There are around 1220 species of barnacle that can be found in the oceans around the world. Most species reside in the shallow coastal areas (few species can be found in deeper parts of the sea). Barnacles have appeared on the planet 510 million years ago and they haven't changed much since that time. Some species of barnacles are used in human diet. Unlike most other sea creatures, barnacles do not feel consequences of the pollution of the sea.
Interesting Barnacle Facts:
Barnacle can reach 0.4 to 2.7 inches in diameter, depending on the species.
Barnacle can be pink, yellow, orange, green, brown or covered with stripes. Color of the body matches with the colors of the habitat and provides camouflage.
Barnacle has hard outer shell which resembles the shell of mollusks. It is made of 6 calcareous plates and usually circular in shape.
Barnacle does not have heart and gills. It breathes through the body wall and via feathery appendages called cirri.
Barnacle swims only short time after hatching and spends the rest of its life attached to the hard surface (rock, shell, boat...).
Barnacle often chooses to settle in the areas where plenty of other barnacles already exist (large number of animals of the same species in a certain area indicates that life conditions are optimal and that food is plentiful).
Besides for rocks, shells and boats, barnacle can be also seen glued for the body of whales, turtles, crabs and other sea creatures. Most animals are not even aware of barnacles on their body because they do not produce harmful effects.
Barnacle is an omnivore. Its diet is based on plankton and algae.
Barnacle is filter-feeder. It collects small particles of food from the water using its feathery appendages (modified legs).
Sea stars, snails (such as whelks) and mussels are natural enemies of both free-swimming larvae and sessile adults.
Mating season of barnacles takes place during the autumn and winter (in the water of low temperature).
Barnacles are hermaphrodites (they possess both types of reproductive organs), but they don't reproduce via self-fertilization.
Barnacles have very large penises which can deliver sperm cells into the body of the nearby barnacles.
Fertilized eggs spend winter inside the sac. Barnacles undergo two larval stages: nauplius and cyprid, before they reach adulthood. Nauplius is free-swimming larva which transforms into cyprid 6 months after hatching. Cyprid phase lasts few days or few weeks. Main goal of this phase is to find suitable substrate. Cyprid secretes sticky substance from the cement gland at the base of its antennas to glue itself to the substrate. Soon afterwards, it starts to produce hard outer shell and transform into adult barnacle.
Barnacle has a lifespan of 5 to 10 years.

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