Lithophyllum incrustans

Researched By	Dr Keith Hiscock	Data Supplied By	MarLIN
Refereed by	Dr Yvonne Chamberlain
Taxonomy
Scientific name	Lithophyllum incrustans	Common name	An encrusting coralline alga
MCS Code	ZM231	Recent Synonyms	None
Phylum	Rhodophycota	Subphylum
Superclass		Class	Rhodophyceae
Subclass	Floridophycidae	Order	Corallinales
Suborder		Family	Corallinaceae
Genus	Lithophyllum	Species	incrustans
Subspecies
Additional Information	Difficult to identify with certainty in the field and often recorded as 'lithothamnia' or 'encrusting Rhodophycota (indet.)' in surveys.
Taxonomy References	Hiscock, 1986b, Irvine & Chamberlain, 1994
General Biology
Growth form	Crustose hard	Feeding method	Photoautotroph
Mobility/Movement	Permanent attachment	Environmental position	Epilithic
Typical food types	Not relevant	Habit	Attached
Bioturbator	Not relevant	Flexibility	None (< 10 degrees)
Fragility	Intermediate	Size	Medium-large(21-50cm)
Height	Insufficient information	Growth Rate	<7 mm/year
Adult dispersal potential	None	Dependency	Independent
Sociability	Colonial
Toxic/Poisonous?	No
Additional Information	Dominant in rockpools and over much of the lower shore and sublittoral fringe at least. Covers the surface of rocks under canopies of algae.
Biology References	Littler, 1972, Irvine & Chamberlain, 1994
Distribution and Habitat
Distribution in Britain & Ireland	Present all around the British Isles but rarer on the east coast between Yorkshire and east Kent. Encrusting coralline species are difficult to distinguish and few surveys record to species level. Its distribution is probably under recorded.
Global distribution	Present in the Faroes, Norway at least south from Trondheimfjord to Spain and the Mediterranean. May also be present in Morocco and Mauritania. Recorded in South Africa (Chamberlain 1996)
Biogeographic range	Not researched	Depth range	Mid-littoral to at least 8 m.
Migratory	Non-migratory / Resident
Distribution Additional Information	No text entered
Substratum preferences	Rockpools	Physiographic preferences	Open coast, Offshore seabed, Strait / sound, Sealoch, Ria / Voe
Biological zone	Mid Eulittoral, Lower Eulittoral, Sublittoral Fringe, Upper Infralittoral	Wave exposure	Extremely Exposed, Very Exposed, Exposed, Moderately Exposed, Sheltered, Very Sheltered
Tidal stream strength/Water flow	Very Strong (>6 kn), Strong (3-6 kn), Moderately Strong (1-3 kn), Weak (<1 kn), Very Weak (negligible)	Salinity	Full (30-40 psu), Variable (18-40 psu)
Habitat Additional Information
Distribution References	Irvine & Chamberlain, 1994, Chamberlain, 1996, Hardy & Guiry, 2003
Reproduction/Life History
Reproductive type	Gonochoristic	Developmental mechanism	Spores (sexual / asexual)
Reproductive Season	October to April	Reproductive Location	Insufficient information
Reproductive frequency	Biannual episodic	Regeneration potential	No
Life span	21-50 years	Age at reproductive maturity	2-3 years
Generation time	Insufficient information	Fecundity	See additional information
Egg/propagule size	Insufficient information	Fertilization type	Insufficient information
Larvae/Juveniles Larval/Juvenile dispersal potential >10km Larval settlement period Insufficient information Duration of larval stage Insufficient information
Additional Information	Gametangial and tetrasporangial plants occur commonly on some shores in Devon and Cornwall but are rare in the north. The 'Time of first and last gamete' refers to the time when reproductive types occur however, some conceptacles are present throughout the year. (Irvine & Chamberlain 1994.) Assuming one layer of conceptacles is produced each year, plants up to 30 years old are reported (Edyvean pers. comm.. in Irvine & Chamberlain 1994). Reproductive types occur from October to April but tail-off into summer. It has been calculated that 1 mm x 1mm of reproductive thallus produces 17.5 million bispores per year with average settlement of only 55 sporelings/year (Edyvean & Ford 1984)
Reproduction References	Irvine & Chamberlain, 1994, Edyvean & Ford, 1984, Edyvean & Ford, 1987