ThePorphyra species of Helgoland (Bangiales, Rhodophyta)

Abstract

"In an investigation into the life-history of an alga the aim should be to obtain a series of observations of the development of the thallus from the germinating spore and then of the development of the reproductive organs on the mature thallus. In cases where both sexual and asexual spores are formed the germination of both types of spore should be followed .... " (Drew, 1954, p. 184) ABSTRACT: This revision of seven Porphyra species of Helgoland was based on a study of the structure of their fertile thalli and the behaviour of their spores. Regarding the reproductive organization the species may be arranged in two groups. P. leucosticta and P. purpureo-violacea are obligate monoecious species, Asexual thalli have never been observed in the field. The other five species are generally dioecious. Isomorphic sexual thalli and asexually propagating ones are mixed in uniform populations. Carpospores originating from sexual fusion develop into the diploid Conchocelis phase. Sporangia of asexual plants, though homologous in formation, produce spores of different kinds: aplanospores that give rise to the vegetative thallus directly {in P. umbilicalis, P. insolita n. sp. and P, ochotensis) and spores that develop into haploid Conchocelis (in P. laciniata and in P. linearis). P. laciniata -formerly considered synonymous with P, purpurea -is an independent species,

Molecular and morphological characters distinguishing twoPorphyraspecies (Rhodophyta: Bangiophycidae)

“…4, all appear to have the characteristics of P. laciniata. This makes sense in view of the fact that Conway based her data on plants that Kornmann & Sahling (1991) realized later were P. Iaciniata.…”

“…by Baker, 1965) following Kornmann (1961). Kornmann & Sahling (1991) stated categorically, however, that the material she studied was their P. laciniata. Conway (I964) in her autecological studies of Porphyra in Britain used the name P. purpurea.…”

“…monoecious in Helgoland. Thirty years later, Kornmann & Sahling (1991) realized that Kornmann's (1961) opinion was incorrect and that P. umbilicalis f. laciniata was distinct from P. purpurea in Helgoland. They provided a description of both species in Helgoland, using the names P. laciniata for P. umbilicalis f. laciniata and P. purpureoviolacea for P. purpurea, following Krishnamurthy (1972) who had found the combination P. purpurea to be illegitimate.…”

The marine macroalgae of Helgoland (North Sea): an annotated list of records between 1845 and 1999

“…P. ochotensis is a doubtful entity and isozyme electrophoresis data suggest that it may be the same as P. dioica (Bartsch, unpublished). P. insolita (Kornmann and Sahling 1991) is a separate species according to Rubisco spacer sequences (Brodie et al 1998), but is particularly difficult to identify in the field as it is similar to P. umbilicalis. P. yezoensis sensu Kornmann was described for Helgoland on the basis of culture studies (Kornmann 1986), but is not the same as Japanese material of P. yezoensis according to Rubisco spacer sequence data (Brodie et al 1998) and not the same as P. insolita.…”

Marine algae of Helgoland: Second supplement

“…Eine ausffihrliche Darstellung fiber die Porphyra-Arten Helgolands und ihre Taxonomie erschien vor wenigen Jahren (Kornmann & Sahling, 1991: The Porphyra species of Helgoland -Bangiales, Rhodophyta). Die hier folgende Fassung soil in erster Linie den Teilnehmern an Kursen als Hflfe ffir die Identifizierung der Arten dienen.…”