Fucus ceranoides

Researched By	Nicola White	Data Supplied By	MarLIN
Refereed by	Dr Graham Scott
Taxonomy
Scientific name	Fucus ceranoides	Common name	Horned wrack
MCS Code	ZR377	Recent Synonyms	None
Phylum	Chromophycota	Subphylum
Superclass		Class	Phaeophyceae
Subclass		Order	Fucales
Suborder		Family	Fucaceae
Genus	Fucus	Species	ceranoides
Subspecies
Additional Information	No text entered
Taxonomy References	Fish & Fish, 1996, Howson & Picton, 1997
General Biology
Growth form	Foliose	Feeding method	Photoautotroph
Mobility/Movement	Permanent attachment	Environmental position	Epifloral
Typical food types	Not relevant	Habit	Attached
Bioturbator	Not relevant	Flexibility	High (>45 degrees)
Fragility	Intermediate	Size	Large(>50cm)
Height	Up to 60 cm	Growth Rate	Insufficient information
Adult dispersal potential	None	Dependency	Independent
Sociability	Solitary
Toxic/Poisonous?	No
Additional Information	Fucus ceranoides is physiologically adapted to brackish conditions. Suryono & Hardy (1997) found that growth rate was highest between 5 and 25 psu and growth was depressed at 0 and 35 psu. When cultured in high salinity they found that plant tissue decayed within 5 to 6 weeks. Khjafi & Norton (1979) recorded similar results but Baeck et al. (1992) found that Fucus ceranoides grew at full salinity for 11 weeks.
Biology References	Suryono & Hardy, 1997, Lein, 1984, Khfaji & Norton, 1979, Fish & Fish, 1996, Baeck et al., 1992
Distribution and Habitat
Distribution in Britain & Ireland	All coasts of Britain and Ireland
Global distribution	Spitsbergen, Iceland, Norway, Heligoland, Netherlands, Ireland, Britain, N. France, Portugal and Azores.
Biogeographic range	Not researched	Depth range	Not relevant
Migratory	Non-migratory / Resident
Distribution Additional Information	The species is commonly found in the upper reaches of estuaries. It appears to be physiologically adapted to living in reduced salinity and exhibits its maximum growth rate at 11 psu. It is thought to be absent from fully saline sites due to an inability to compete with the faster growing fucoids, such as %Fucus vesiculosus% and a physiological intolerance of fully saline conditions. In areas of estuaries where salinity varies between 11 and 25 psu, Fucus ceranoides and %Fucus vesiculosus% can be found living together.
Substratum preferences	Bedrock, Large to very large boulders, Small boulders, Cobbles, Pebbles, Gravel / shingle	Physiographic preferences	Estuary, Strait / sound, Sealoch, Ria / Voe, Open coast
Biological zone	Upper Eulittoral, Mid Eulittoral	Wave exposure	Sheltered, Very Sheltered
Tidal stream strength/Water flow	Strong (3-6 kn), Moderately Strong (1-3 kn), Weak (<1 kn), Very Weak (negligible)	Salinity	Reduced (18-30 psu), Low (<18 psu)
Habitat Additional Information
Distribution References	Suryono & Hardy, 1997, Lein, 1984, JNCC, 1999, Norton, 1985, Hardy & Guiry, 2003
Reproduction/Life History
Reproductive type	Gonochoristic	Developmental mechanism	Insufficient information
Reproductive Season	Insufficient information	Reproductive Location	Insufficient information
Reproductive frequency	Annual episodic	Regeneration potential	No
Life span	3-5 years	Age at reproductive maturity	Insufficient information
Generation time	Insufficient information	Fecundity	Insufficient information
Egg/propagule size	Insufficient information	Fertilization type	Insufficient information
Larvae/Juveniles Larval/Juvenile dispersal potential Insufficient information Larval settlement period Not relevant Duration of larval stage Insufficient information
Additional Information	The species is usually dioecious but monoecious plants have been recorded, although it has been suggested that these are hybrids. Well developed gametangia are present on plants in southern Norway from the end of May to December. Gametes are released on daytime high tides at about full and new moon. Germlings are found from the end of May to the beginning of August. Receptacles usually drop off by October or November.
Reproduction References	Lein, 1984, Brawley, 1992, Baeck et al., 1992