Title: Observation on the Distribution of “Conchocelis-phase” of Porphyra tenera Kjellman in the Oyster-shell
Abstract: The shells of Ostrea denselamellosa were experimentally set near to the mature thalli of Porphyra tenera in the sea from Feb. 6 till Apr. 8 1956. Then the Conchocelis-phase of porphyra invaded within the shells was cultured in a laboratory tank till June 6, when the growth and distribution of Conchocelis was examined. It was acknowledged that the Conchocelis grows in a greater number in the left valva than the right ones, and it distributes in most abundance in the section A of the shell, shown in Fig. 1 (Tab. 1). As to the vertical distribution, the Conchocelis phase appears in every layer spreading from the sea surface to the bottom of about 250cm. in depth, and especially in abundance in 24-36cm. zone above the bottom. (Tab. 2). As the chalky-deposit of the oyster shell becomes thinner where the surface layer of the shell shows dark violet color owing to the luxuriant growth of Conchocelis-filaments, it seems probable that the chalky-deposit has some close relation to the growth of the Conchocelis.