A Study on the Influence of Some Environmental Factors Upon the Development and the Maturity of the Conchocelis-phase of a Laver, Porphyra tenera KJELLMANN

The present study was carried out to clarity the influence of the environmental factors such as chlorinity of sea water, burying in the mud, and desiccation in the air, on Conchocelis-phase of a laver, Porphyra tenera KJELLMANN. Results are as follows: (1) In dilute sea water (less than 10 Cl ‰) the development of carpospores into the Conchocelis is retarded and disturbed. The development of the Conchocelis which has penetrated within oyster shell is almost unaffected by lower chlorinity, although only some delay in growth is observed in its younger stage. The formation of sporangia on the Conchocelis is delayed by the effect of lower chlorinity. (2) When the Conchocelis is buried by various kinds of bottom substances, it stops to grow. If it is returned into normal condition after shorter periods of burying, it can grow further and become mature, But it can not resist longer in the mud or muddy sand which are rich in organic substances. (3) The Conchocelis is fatally-affected by desiccation and direct sunlight when they are exposed in the air. It dies in about 15 minutes outdoors and in about 30 minutes indoors.