Home / Browns / Macrocystis

Home button

Click on images for larger format

Name derivation:

Macrocystis: L. macro- large+ cystis- a cavity

pyrifera; L.pyriform in shape

Common name: Giant kelp

Classification:

Macrocystis C.Agardh 1820; there are 18 species of which 1 has been taxonomically accepted.

Order Laminariales; Family Laminariaceae

Morphology:

The largest seaweed in the world, growing to 60 m long. Thallus consists of a large massive holdfast, multiple stipes, 'pneumatocysts' (air-filled bladders) for floatation at the upper end of the stipes, and corrugated blades.

Species of Macrocystis are distinguished primarily on the basis of their holdfast morphologies.

Species are distinguished primarily on characteristics of the holdfast.

Macrocystis is a perennial.

 

Fastest growth rate of all organisms

M. pyrifera holds the record for fastest elongation of up to 60 cm per day and more tha 45 m in one growing season.

Similar genera:

Nereocystis, Laminaria, Saccharina

Habitat:

Growing in semi-exposed open coastal habitats, forming extensive kelp 'forests'. It is harvested for aligin (alginic acid) in some temperates areas of the world (e.g. California).  Distribution includes North and South America, South Africa, New Zealand and southern Australia.

 

 

Use:

Macrocystis is harvested for the commercial extraction of alginin. Harvest in California has been restricted to the upper two meters of the algae, considered to be a minimal affect on the kelp forest because growth continues from the base, is rapid, and the algae are perennial.

 

References:

Abbott I. A. and G. J. Hollenberg. 1976, Marine Algae of California. Stanford University Press, Stanford, xii + 827 pp.

Agardh, C.A. (1820 '1821'). Species algarum rite cognitae, cum synonymis, differentiis specificis et descriptionibus succinctis. Volumen primum. Pars prima. pp. [i-iv], [1]-168. Lundae [Lund]: ex officina Berlingiana.

Guiry, M.D., and G.M. Guiry 2013. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 16 January 2013.

 

 

 

 

Home / Browns / Macrocystis