The Perforating Growth of Conchocelis into the Substratum of Coralline Algae

The perforating growth of Conchocelis-phase of Porphyra in various substrata such as shells and calcareous stones are well known. In this work, the penetrating growth of Conchocelis was obserbed experimentally, using the dead thalli of coralline algae, Lithophyllum okamurai, L. yendoi, Goniolithon sp., as substrata. On the other hand, the resistibility of Conchocelis against desiccation and direct sunlight were investigated in the laboratory. The results are as follows; 1) On the coralline algae, the carpospore of Porphyra germinates, and then penetrates into the inner layer of the thallus. It develops to the Conchocelis-phase as in the shell (Fig. 1). 2) The Conchocelis-filaments grow along the calcium depositing layer between cells. Consequently the arrangement of Conchocelis-filaments becomes very curious. The sporangia of the Conchocelis-phase are also similar to the case of shells. 3) When the Conchocelis is exposed to direct sunlight in the air, it dies after about 10 minutes, but in the shade it survives for about 40 minutes (Tab. 2-3). 4) Some dead coralline algae containing Conchocelis-filaments were collected in the culture ground of laver in Ariake Bay