
Species profile
Giant Acorn Barnacle
Balanus nubilus
At a glance
Giant Acorn Barnacle (Balanus nubilus) is a barnacle regulated in 2 of 66 jurisdictions tracked by CatchRules across the U.S. and Canada.
Bag limits are uniform at 6 per angler across the 2 regulating jurisdictions.
Confirmed by 1,060 research-grade iNaturalist observations, with British Columbia, California, and Washington the top jurisdictions by observation count.
Notable details
- One of the world's largest barnacle species, reaching up to 7 cm (3 inches) tall.
- Found along the Pacific coast from Alaska to Baja California on rocks and pilings.
- Sweeps the water with feathery cirri to capture plankton and organic particles.
- Can live 10–15 years, making it one of the longest-lived barnacle species.
- Once attached as an adult, it cements itself to hard surfaces permanently and never moves.
Where Giant Acorn Barnacle are seen
Jurisdictions with rules for Giant Acorn Barnacle
Background
Balanus nubilus, commonly called the giant acorn barnacle, is the world's largest barnacle, reaching a diameter of 15 centimetres (5.9 in) and a height of up to 30 centimetres (12 in), and containing the largest known muscle fibres.
Background excerpt adapted from Wikipedia's Giant Acorn Barnacle article (CC BY-SA). Visit Wikipedia for the full entry.
Other barnacles on CatchRules
Photo credit: iNaturalist / Wikipedia. Identification reference only — verify regulations with the issuing wildlife agency before retaining a catch.