BIOTIC Species Information for Pelvetia canaliculata
Researched byNicola White Data supplied byMarLIN
Refereed byDr Dagmar Stengel
Scientific namePelvetia canaliculata Common nameChannelled wrack
MCS CodeZR386 Recent SynonymsNone

PhylumChromophycota Subphylum
Superclass ClassPhaeophyceae
Subclass OrderFucales
Suborder FamilyFucaceae
GenusPelvetia Speciescanaliculata

Additional InformationPelvetia canaliculata has an obligate endophytic fungus Mycosphaerella acophylli (Ascomycetes).
Taxonomy References Subrahmanyan, 1960,
General Biology
Growth formShrub
Feeding methodPhotoautotroph
Mobility/MovementPermanent attachment
Environmental positionEpifloral
Typical food typesNo text entered HabitAttached
BioturbatorNot relevant FlexibilityHigh (>45 degrees)
FragilityIntermediate SizeMedium(11-20 cm)
HeightUp to 15 cm Growth Rate3-4 cm/year
Adult dispersal potentialNone DependencyIndependent
General Biology Additional InformationPelvetia canaliculata is very tolerant of desiccation. It may spend up to 90 percent of the time out of the water and can tolerate 65 percent water loss. The species can photosynthesise when exposed to air but may suffer nutrient stress as it can only obtain nutrients when submerged. The species supports an impoverished fauna due to the harsh physical conditions on the upper shore. A few species of wandering isopods and amphipods may be found sheltering underneath the fronds at low tide.
Biology References Subrahmanyan, 1960,
Distribution and Habitat
Distribution in Britain & IrelandAll coasts of Britain and Ireland
Global distributionNorway, Iceland, UK, Ireland, Atlantic coast of France, Spain and Portugal.
Biogeographic rangeNot researched Depth rangeNot relevant
MigratoryNon-migratory / Resident   
Distribution Additional Information
  • Pelvetia canaliculata is the highest living fucoid on the shore. The upper limits of the species distribution are controlled by its physiological tolerances, whereas it's lower limits on the shore are controlled by its ability to compete with %Fucus spiralis%. Pelvetia canaliculata is capable of growing further down the shore but it is out-competed by faster growing species such as %Fucus spiralis% and is also heavily grazed. However, this is one of the few algae which requires regular aerial exposure to survive and prolonged submersion, such as in rockpools actually kills the algae.
  • In moderately exposed conditions Pelvetia canaliculata is capable of growing above the high water mark, where it is supplied with water through spray and waves. In sheltered conditions it grows further down the shore where it will be immersed by spring tides but often not covered by neaps. It has been estimated that some plants spend up to 90 percent of their time out of the water (Fish & Fish, 1996).
  • Pelvetia canaliculata lives in some lower salinity sites although the balance between the algae and the obligate endophytic fungus Mycosphaerella ascophylli seems to be affected (D. Stengel pers. comm.)

Substratum preferencesBedrock
Large to very large boulders
Small boulders
Physiographic preferencesOpen coast
Strait / sound
Ria / Voe
Biological zoneLower Littoral Fringe
Wave exposureModerately Exposed
Very Sheltered
Tidal stream strength/Water flowStrong (3-6 kn)
Moderately Strong (1-3 kn)
Weak (<1 kn)
SalinityFull (30-40 psu)
Variable (18-40 psu)
Habitat Preferences Additional Information
Distribution References Subrahmanyan, 1960, Fish & Fish, 1996, Hardy & Guiry, 2003, NBN, 2002,
Reproduction/Life History
Reproductive typePermanent hermaphrodite
Developmental mechanismNot relevant
Reproductive SeasonAugust to September Reproductive LocationInsufficient information
Reproductive frequencyAnnual episodic Regeneration potential No
Life span3-5 years Age at reproductive maturity1-2 years
Generation time1-2 years FecundityInsufficient information
Egg/propagule sizeInsufficient information Fertilization typeExternal
Larval/Juvenile dispersal potentialInsufficient information Larval settlement periodInsufficient information
Duration of larval stageInsufficient information   
Reproduction Preferences Additional Information
  • Age at maturity:In Ireland Pelvetia canaliculata is at least two years old before it reaches maturity (D. Stengel pers. comm.)
  • Pelvetia canaliculata produces gametes within receptacles on the tips of the fronds. Receptacles are initiated in January when they start to swell and become distinguishable. In July, the receptacles start ripening and gametes are released from August to early September, after which the receptacles are shed. Gametes are fertilised externally forming zygotes which then settle. A sporeling is produced of 800um length in six months. Plants first produce receptacles at a size of 4 to 5 cm long when they are in their first year.
Reproduction References Subrahmanyan, 1960,
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