Arthropoda · arthropods

Northern rock barnacle

Semibalanus balanoides

Archaeobalanidae · acorn barnaclesIUCN: Not evaluated

A white acorn barnacle that forms a band on Northeast rocky shores.

Fun factBarnacles glue themselves down head-first and kick food into their mouths with their legs.

Classification

Arthropoda › Thecostraca › Archaeobalanidae

Kingdom Animalia animals
- Many-celled organisms that eat other living things for energy (heterotrophs)
- Cells have no cell walls
- Most can move at some stage of life
Clade Bilateria bilateral animals
- Body has a left and right side that mirror each other (bilateral symmetry)
- Head end with concentrated nerves; three tissue layers
- Includes about 99% of all living animal species
Clade Protostomia protostomes
- In the embryo, the first opening usually becomes the mouth
- Main nerve cord runs along the belly (ventral)
- Includes mollusks, worms, and arthropods
Clade Ecdysozoa molting animals
- Grow by shedding their outer layer (molting, ecdysis)
- No cilia used for movement
- Includes arthropods and nematode worms
Phylum Arthropoda arthropods
- Hard outer skeleton made of chitin (exoskeleton)
- Jointed legs and a segmented body
- The largest animal phylum by species count
Subphylum Crustacea crustaceans
- Two pairs of antennae
- Branched (biramous) legs in many species
- Most breathe with gills
Class Thecostraca barnacles
- Barnacles: adults cement themselves head-down to a surface
- Kick food into the mouth with feathery legs (cirri)
Family Archaeobalanidae acorn barnacles
- Acorn barnacles with a cone of hard wall plates
Genus Semibalanus
- Species in the same genus are very close relatives and often look alike.
Species Semibalanus balanoides Northern rock barnacle