BIOTIC

BIOTIC Species Information for Phymatolithon calcareum
All Taxonomy Biology Distribution Reproduction

Researched by	Angus Jackson	Data supplied by	MarLIN
Refereed by	Dr Christine Maggs
General Biology
Growth form	Algal gravel	Feeding method	Photoautotroph
Mobility/Movement	See additional information	Environmental position	Epifloral
Typical food types	Not relevant	Habit	Bed forming
Bioturbator	Not relevant	Flexibility	None (< 10 degrees)
Fragility	Fragile	Size	Small-medium(3-10cm)
Height	Insufficient information	Growth Rate	1-2 mm/year
Adult dispersal potential	10-100m	Dependency	Independent
Sociability	Gregarious
Toxic/Poisonous?	No
General Biology Additional Information	Mobility is recorded as not relevant here since Phymatolithon calcareum does not fall into the available categories. It does have a crustose permanently attached form but this has not been recorded in the British Isles. It is typically found as an unattached plant. Coralline algal thalli that form maerl beds have been found in densities of up to 22,000 thalli per square metre. The proportion of live to dead nodules varies considerably. As far as is known maerl continues to grow throughout its life but fragmentation limits the size of the nodules. There are no sexes and individual plants may reach up to 5 cm across. Maerl beds are highly species rich with 150 macroalgal species and over five hundred faunal species (of which 120 are molluscs) recorded as living on or in maerl beds (Birkett et al., 1998(a)); see the maerl biotope £IGS.Phy.HEc£ for further information. As far as is known, the maerl does not host any commensal or parasitic species. However, a few algae are almost entirely restricted to maerl communities e.g. the red algae Gelidiella calcicola, Gelidium maggsiae and the crustose Cruoria cruoriaeformis (Birkett et al., 1998(a)).
Biology References	Adey & McKibbin, 1970, Donnan & Davies, 1996, Birkett et al., 1998(a), Potin et al., 1990, Grall & Glémarec, 1997, Hall-Spencer & Moore, 2000a,