Pelvetia canaliculata

Researched By	Nicola White	Data Supplied By	MarLIN
Refereed by	Dr Dagmar Stengel
Taxonomy
Scientific name	Pelvetia canaliculata	Common name	Channelled wrack
MCS Code	ZR386	Recent Synonyms	None
Phylum	Chromophycota	Subphylum
Superclass		Class	Phaeophyceae
Subclass		Order	Fucales
Suborder		Family	Fucaceae
Genus	Pelvetia	Species	canaliculata
Subspecies
Additional Information	Pelvetia canaliculata has an obligate endophytic fungus Mycosphaerella acophylli (Ascomycetes).
Taxonomy References	Subrahmanyan, 1960
General Biology
Growth form	Shrub, Foliose	Feeding method	Photoautotroph
Mobility/Movement	Permanent attachment	Environmental position	Epifloral
Typical food types	No text entered	Habit	Attached
Bioturbator	Not relevant	Flexibility	High (>45 degrees)
Fragility	Intermediate	Size	Medium(11-20 cm)
Height	Up to 15 cm	Growth Rate	3-4 cm/year
Adult dispersal potential	None	Dependency	Independent
Sociability	Solitary
Toxic/Poisonous?	No
Additional Information	Pelvetia 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 & Ireland	All coasts of Britain and Ireland
Global distribution	Norway, Iceland, UK, Ireland, Atlantic coast of France, Spain and Portugal.
Biogeographic range	Not researched	Depth range	Not relevant
Migratory	Non-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 preferences	Bedrock, Large to very large boulders, Small boulders, Cobbles	Physiographic preferences	Open coast, Strait / sound, Sealoch, Ria / Voe
Biological zone	Lower Littoral Fringe	Wave exposure	Moderately Exposed, Sheltered, Very Sheltered
Tidal stream strength/Water flow	Strong (3-6 kn), Moderately Strong (1-3 kn), Weak (<1 kn)	Salinity	Full (30-40 psu), Variable (18-40 psu)
Habitat Additional Information
Distribution References	Subrahmanyan, 1960, Fish & Fish, 1996, Hardy & Guiry, 2003, NBN, 2002
Reproduction/Life History
Reproductive type	Permanent hermaphrodite	Developmental mechanism	Not relevant
Reproductive Season	August to September	Reproductive Location	Insufficient information
Reproductive frequency	Annual episodic	Regeneration potential	No
Life span	3-5 years	Age at reproductive maturity	1-2 years
Generation time	1-2 years	Fecundity	Insufficient information
Egg/propagule size	Insufficient information	Fertilization type	External
Larvae/Juveniles Larval/Juvenile dispersal potential Insufficient information Larval settlement period Insufficient information Duration of larval stage Insufficient information
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