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Life History and Growth of the Epiphytic Thallus of Porphyra lacerata (Bangiales, Rhodophyta) in Culture

1998; Korean Society of Phycology; Volume: 13; Issue: 2 Linguagem: Inglês

2093-0860

Masahiro Notoya, Kazuhiro Nagaura,

Polar Research and Ecology

This is the first report on small epiphytic foliose thalli of Porphyra lacerata from Banda, Chiba Prefecture, Japan. Matured foliose thalli from the field were in maximum length and width, and occurred as epiphytes on Myeluphycus simplex or Ishige okamurae. They were clearly smaller than those of epilithic thalli from Enoshima, Kanagawa Prefecture. Zygotospores and conchospores were cultured to observe their life history at various temperatures (5, 10, 15, 20, 25 and ) and two photoperiods (14L:10D and 10L:14D) under a photon flux density of . Typical biphasic cycle of the P. lacerata-type was observed. The foliose thalli produced archeospores at under both photoperiods, and produced zygotospores at under short photoperiod and at under long photoperiod. The foliose thalli and the conchocelis filaments could not survive at . The maximum size of foliose thallus, () was observed at under a 10L:14D after 15 weeks in culture. The size and shape of thalli in culture were similar to the field materials, epiphytic on Myeolphycus simplex. Hus' formula in cultured thalli, was 64 (a/4, b/4, c/4) or 32 (a/4, b/2, c/4) in spermatangium and 8 (a/2, b/2, c/2) or 4 (a/2, b/1, c/2) in zygotosporangium, respectively. Zygotospore germlings grew to conchocelis filaments. It grew quickly at under long photoperiod. Conchosporangial branches were produced at under both photoperiods. Conchocelis produced neither monospores nor protothalli.