Balanus nubilus
| Balanus nubilus | |
|---|---|
| Giant acorn barnacles with cirri extended for feeding | |
| Scientific classification | |
| Domain: | Eukaryota | 
| Kingdom: | Animalia | 
| Phylum: | Arthropoda | 
| Class: | Thecostraca | 
| Subclass: | Cirripedia | 
| Order: | Balanomorpha | 
| Family: | Balanidae | 
| Genus: | Balanus | 
| Species: | B. nubilus | 
| Binomial name | |
| Balanus nubilus Darwin, 1854 | |
Balanus nubilus, commonly called the giant acorn barnacle, is the world's largest barnacle, reaching a diameter of 15 cm (6 in) and a height of up to 30 cm (12 in), and containing the largest known muscle fibres.