Life cycles Porphyra

Question 1

What is the genus of Porphyra?

Answer 1

Rhodophyta, Bangiales

Question 2

What led to the cultivation of Porphyra in Japan in the XVII century?

Answer 2

Demand for Porphyra as food was higher than availability from the sea.

Question 3

What cultivation method was used for Porphyra until 1949?

Answer 3

Empirical systems, including planting bamboo poles supporting ropes in autumn and moving them to sandy areas in winter.

Question 4

What did Kathleen Drew Baker’s publication reveal about Porphyra?

Answer 4

That the microscopic red alga settled on shells, known as the genus Conchocelis, is actually the sporophyte of Porphyra.

Question 5

How did Kathleen Drew Baker’s finding change Nori cultivation?

Answer 5

It allowed for the development of biomass cultivation of Nori in Asian areas.

Question 6

What are the 5 steps involved in the cultivation of Nori?

Answer 6

1. Production and harvesting of carpospores and inoculum on mollusc shells.
2. Mass cultures of conchocelis phase on sterile oyster shells.
3. Keeping in culture of conchocelis phase in hatchery (May – October).
4. Induction of conchospores production and settlement on floating or fixed nets through suitable environmental conditions.
5. Transplanting of nets in the sea for foliose thallus growth (~35 cm in length) (October – April).

Question 7

What recent development has been made in Nori cultivation?

Answer 7

It has been shown that “free” conchocelis can be produced and kept in large quantities in Bioreactors.

Question 8

What do we see in the picture?

Answer 8

Cultures of conchocelis on oyster shells in hatchery

Optimal growth between 20-25 °C.

Question 9

What do we see here?

Answer 9

Free conchocelis can be cultivated in this bioreactor.

Question 10

What do we see here?

Answer 10

Floating or fixed nets, supporting the young foliose thalli, are settled on bamboo poles

Question 11

What do we see here?

Answer 11

Harvesting of Porphyra thalli from the farms in the sea

Question 12

What do we see here?

Answer 12

End result of Nori cultivation

Question 13

Most common cultivated porphyra species in Japan and China are..

Answer 13

• Neopyropia yezoensis
• Pyropia tenera

Question 14

What does this map show?

Answer 14

Main producer countries of Pyropia tenera (FAO Fishery Statistics, 2006)

Question 15

Global aquaculture production of Pyropia tenera (FAO Fishery Statistic)

Answer 15

Question 16

Porphyra umbilicalis (Atlantic Nori)

Answer 16

• It is a common and abundant species of Porphyra along the European coasts of the North Atlantic
• Also known as: Purple Laver; Pink Laver; Laver
• Atlantic nori is not cultivated
• It is collected exclusively from marine spontaneous populations.

Question 17

Uses of the Porphyra (Nori) species

Answer 17

• Primary use: as food (high nutritional value, pleasant taste)
• Phycoerythrin production
  (used as a fluorescent dye in diagnostics)
• As a source of food supplements