PORPHYRA

'''Porphyra''' is a foliose red algal genus of about 70 species.^[1] It lives in the intertidal, typically between the upper intertidal to the splash zone. It is used to make nori, the most commonly eaten seaweed.

Contents

''Porphyra''

Life cycle

Food

References

External links

''Porphyra''

It is considered that there are 60 to 70 species of ''Porphyra'' worldwide^[2] and seven in the British Isles.^[3]

Life cycle

''Porphyra'' displays a alternation of generations. The thallus we see is the haploid generation, it can reproduce asexually by forming spores which grow to replicate the original thallus. It can also reproduce sexually. Both male and female gametes are formed on the one thallus. The female gametes while still on the thallus are fertilized by the released male gametes, which are non-motile. The fertilised, now diploid, carposporangia after meiosis produce spores (carpospores) which settle, then bore into shells, germinate and form a filamentous stage. This stage was originally thought to be a different species of alga, and was referred to as ''Conchocelis rosea''. It is now known to be the diploid stage of ''Porphyra''. ^[4] [1]

Food

Most human cultures with access to ''Porphyra'' use it as a food or somehow in the diet, making it perhaps the most domesticated of the marine algae, ^[5] known as laver, nori, zakai, kim, karengo, sloke or slukos.
The marine red alga ''Porphyra'', which is called ''nori'' in Japanese, has been cultivated extensively in many oriental countries as an edible seaweed used to wrap the rice and fish that compose the Japanese food sushi. In Japan, the annual production of ''Porphyra'' spp. is valued at 100 billion yen (US$ 1 billion).^[6]

References

1. 'Brodie, J.A. and Irvine, L.M.' 2003. ''Seaweeds of the British Isles.'' Volume 1 Part 3b. The Natural History Museum, London.ISBN 1 898298 87 4
2. 'Kain, J.M.' 1991. Cultivation of attached seaweeds. ''in'' Guiry, M.D. and Blunden, G. 1992. ''Seaweed Resources in Europe: Uses and Potential.'' John Wiley and Sons, Chichester ISBN 0 471 92947 6
3. 'Hardy, F.G. and Guiry, M.D.' 2006. ''A Check-list and Atlas of the Seaweeds of Britain and Ireland.'' British Phycological Society, London. ISBN 3 906166 35 X
4. 'Thomas, D.' 2002. ''Seaweeds.'' The Natural History Museum, London. ISBN 0 565 09175 1
5. 'Mumford, T.F. and Miura, A.' 4.''Porphyra'' as food: cultivation and economics. in Lembi, C.A. and Waaland, J.R. 1988. ''Algae and Human Affairs.'' Cambridge University Press, Cambridge. ISBN 0-521-32115-8
6. 'Aoki, Y. and Kamei, Y.' 2006 Preparation of recombinant polysaccharide-degrading enzymes from the marine bacterium, ''Pseudomonas'' sp. ND137 for the production of protoplasts of ''Porphyra yezoensis'' ''Eur. J. Phycol.'' '41': 321 - 328

External links

★ http://www.mbari.org/staff/conn/botany/reds/lisa/consume.htm