BIOTIC

BIOTIC Species Information for Balanus crenatus
All Taxonomy Biology Distribution Reproduction

Researched by	Nicola White	Data supplied by	MarLIN
Refereed by	Prof. Alan J. Southward
General Biology
Growth form	Conical	Feeding method	Passive suspension feeder Active suspension feeder
Mobility/Movement	Permanent attachment	Environmental position	Epifaunal Epilithic
Typical food types	Zooplankton and other organic particles of a suitable size, such as detritus and phytoplankton.	Habit	Attached
Bioturbator	Not relevant	Flexibility	None (< 10 degrees)
Fragility	Robust	Size	Small(1-2cm)
Height	Insufficient information	Growth Rate	4.4 mm/month
Adult dispersal potential	None	Dependency	Independent
Sociability	Gregarious
Toxic/Poisonous?	No
General Biology Additional Information	Balanus crenatus has a calcareous base, while Semibalanus balanoides has a membranous base. Feeding Balanus crenatus feeds by extending thoracic appendages called cirri out from the shell to filter zooplankton from the water. In the absence of any current, the barnacle rhythmically beats the cirri. When a current is present Balanus crenatus holds the cirri fully extended in the current flow. Barnacles feed most during spring and autumn when plankton levels are highest. Little if any feeding takes place during winter, when barnacles rely on stored food reserves. Feeding rate is important in determining the rate of growth. Moulting Barnacles need to moult in order to grow. Frequency of moulting is determined by feeding rate and temperature. Moulting does not take place during winter when phytoplankton levels and temperatures are low. Size: Balanus crenatus is hermaphroditic and grows up to 25mm in diameter.
Biology References	Rainbow, 1984, Barnes et al., 1963, Bassindale, 1964,