Abstracts of papers read at the winter meeting at University College,London 2–4 January 1974

Dermocorynus montagnei Crouan frat., a red seaweed previously known only from a few dredged specimens collected in the Bretagne region of France, mostly in the last century, has been found growing subtidally on small stones at two sites in Galway Bay. Tetrasporangial and cystocarpic plants are present during most of the year and an account of the structure and development of these is given. It is concluded from these studies that Dermocorynus Crouan frat. is correctly placed in the Halymeniaceae Bory (=Cryptonemiaceae Harv.) and is best characterized generically by its unusual habit rather than by any of its reproductive characters. Culture studies show that the species has a Polysiphonia-type life history.     

Biosystematics of Gracilaria foliifera (Gigarthales, Rhodophyta)

Strains of Gracilaria foliifera (Forsskål) Børgesen isolated into culture from Ireland (where the species would appear to be introduced), England and the Atlantic coast of France were interfertile. Strains of G. foliifera from Texas and North Carolina, U.S.A. were similarly interfertile but did not cross with the European strains. The North Carolina strain was distinctly flattened in culture and superficially resembled G. foliifera from Europe whereas the Texas strain was terete or slightly flattened. Both of the American strains were interfertile with an isolate of G. tikvahiae McLa-chlan from the type locality of this species in northern Nova Scotia, Canada. It seems likely from these data that G. foliifera is not represented on the coast of North America and that G. tikvahiae is a highly morphologically variable species widely distributed from Nova Scotia south to the Caribbean. Examination of type material of Gracilaria foliifera and G. multipartita (Clemente) Harvey, together with phyto-geographical considerations, suggests that the species known as G. foliifera on eastem Atlantic masts should be known as G. rnultipartita , and that G. foliifera s. str . is probably confined to the Red, Arabian, and Indian Seas.     

A Higher Level Classification of All Living Organisms

We present a consensus classification of life to embrace the more than 1.6 million species already provided by more than 3,000 taxonomists’ expert opinions in a unified and coherent, hierarchically ranked system known as the Catalogue of Life (CoL). The intent of this collaborative effort is to provide a hierarchical classification serving not only the needs of the CoL’s database providers but also the diverse public-domain user community, most of whom are familiar with the Linnaean conceptual system of ordering taxon relationships. This classification is neither phylogenetic nor evolutionary but instead represents a consensus view that accommodates taxonomic choices and practical compromises among diverse expert opinions, public usages, and conflicting evidence about the boundaries between taxa and the ranks of major taxa, including kingdoms. Certain key issues, some not fully resolved, are addressed in particular. Beyond its immediate use as a management tool for the CoL and ITIS (Integrated Taxonomic Information System), it is immediately valuable as a reference for taxonomic and biodiversity research, as a tool for societal communication, and as a classificatory “backbone” for biodiversity databases, museum collections, libraries, and textbooks. Such a modern comprehensive hierarchy has not previously existed at this level of specificity.     

Crystal polymorphism of pharmaceuticals: probing crystal nucleation at the molecular level

Paracetamol, sulfathiazole and L-glutamic acid are presented as examples of pharmaceutical crystal polymorphic systems. The effect of N-acylated sulfathiazole derivatives (3-6) on sulfathiazole crystallisation is discussed, and possible modes of action presented. Methods for the control of the crystal polymorphism of L-glutamic acid which utilise the principles of conformation mimicry and co-operative binding are presented. The preparation of a series of bis-amides of EDTA derived from sulfathiazole, 5-aminoisophthalic acid and 4-hydroxyaniline (i.e. compounds 9a-c) is presented, as is data on the effect of these compounds on the crystallisation of, respectively, sulfathiazole, L-glutamic acid and paracetamol.     

MOLECULAR PHYLOGENY OF ANTARCTIC PRASIOLA (PRASIOLALES,TREBOUXIOPHYCEAE) REVEALS EXTENSIVE CRYPTIC DIVERSITY1

Trebouxiophytes of the genus Prasiola are well known in Antarctica, where they are among the most important primary producers. Although many aspects of their biology have been thoroughly investigated, the scarcity of molecular data has so far prevented an accurate assessment of their taxonomy and phylogenetic position. Using sequences of the chloroplast genes rbcL and psaB, we demonstrate the existence of three cryptic species that were previously confused under Prasiola crispa (Lightfoot) Kützing. Genuine P. crispa occurs in Antarctica; its presence was confirmed by comparison with the rbcL sequence of the type specimen (from the Isle of Skye, Scotland). Prasiola antarctica Kützing is resurrected as an independent species to designate algae with gross morphology identical to P. crispa but robustly placed in a separate lineage. The third species is represented by specimens identified as P. calophylla (Carmichael ex Greville) Kützing in previous studies, but clearly separated from European P. calophylla (type locality: Argyll, Scotland); this alga is described as P. glacialis sp. nov. The molecular data demonstrated the presence of P. crispa in Maritime and Continental Antarctica. P. antarctica was recorded from the Antarctic Peninsula and Shetland Islands, and P. glacialis from the Southern Ocean islands and coast. Such unexpected cryptic diversity highlights the need for a taxonomic reassessment of many published Antarctic records of P. crispa. The results also indicate that marine species of Prasiola form a well‐supported monophyletic group, whereas the phylogenetic diversity of freshwater species is higher than previously suspected (at least three separate lineages within the genus include species living in this type of environments).     

HOW MANY SPECIES OF ALGAE ARE THERE?

Algae have been estimated to include anything from 30,000 to more than 1 million species. An attempt is made here to arrive at a more accurate estimate using species numbers in phyla and classes included in the on‐line taxonomic database AlgaeBase ( http://www.algaebase.org ). Despite uncertainties regarding what organisms should be included as algae and what a species is in the context of the various algal phyla and classes, a conservative approach results in an estimate of 72,500 algal species, names for 44,000 of which have probably been published, and 33,248 names have been processed by AlgaeBase to date (June 2012). Some published estimates of diatom numbers are of over 200,000 species, which would result in four to five diatom species for every other algal species. Concern is expressed at the decline and potential extinction of taxonomists worldwide capable of improving and completing the necessary systematic studies.     

Life history regulation and phenology of the red algaBonnemaisonia hamifera

Bonnemaisonia hamifera Hariot (Rhodophyceae, Bonnemaisoniales) from Galway Bay, Ireland has been studied in the field and in laboratory culture. The reproductive behaviour of tetrasporophytes and gametophytes in the field appeared to be strictly regulated by their temperature/daylength responses as observed in culture. Tetrasporangia were abundant in early autumn when short days (<12 h of light per day) coincided with seawater temperatures over about 11°C, the lower limit for sporangium formation. Spermatangia were observed in very young gametophytes between mid-December and February, and in adult plants from late March until the end of May. They were absent in mid-winter when low temperatures of about 2°C inhibited their formation. Carpogonia were first observed at the end of April as seawater temperatures had by then risen to the required value of around 10°C. Carpogonia were fertilised and plants with mature cystocarps were present until early July. The onset of reproduction was accompanied by a cessation of growth and led to senescence within 2–3 months. Thus, gametophytes were absent in summer in spite of persistently favourable seawater temperatures. In various parts of the North Atlantic Ocean, annual temperature regimes are such as to cause a certain lack of synchronisation in the occurrence of reproductive male and female plants. This may account for the many anomalous reports of reproductive plants in the wild. Dedicated to Dr. Dr. h. c. P. Kornmann on the occasion of his eightieth birthday.     

A species of Cryptonemia new to Europe

The morphology, reproduction and seasonal variation of a large foliose species of Cryptonemia collected in the drift in 1971–73 at Cork Harbour, Republic of Ireland, is described and compared with the known species of the genus. Although obviously closely related to a group of foliose Pacific species: C. borealis Kylin, C. obovata J. Ag. and C. angustata (Setch. et Gardn.) Dawson, the Irish Cryptonemia is not completely identifiable with any one of these and is therefore described as C. hibernica sp. nov., pending a revision of the genus.     

SEASONAL GROWTH AND PHENOTYPIC VARIATION IN PORPHYRA LINEARIS (RHODOPHYTA) POPULATIONS ON THE WEST COAST OF IRELAND1

The phenology and seasonal growth of Porphyra linearis Grev. were investigated in two morphologically dissimilar populations from the west coast of Ireland. Thallus size and reproductive status of individuals were monitored monthly between June 1997 and June 1998. Both populations exhibited a similar phenology: gametophyte stages appeared on the shore in October, with spermatangial and zygotosporangial sori appearing the following February; the gametophyte stage began to degenerate in April and had disappeared completely by June. However, significant differences in growth and reproduction in the field and in cultures of plants from the two populations were observed. Thallus length and width of individuals from one population were significantly longer throughout the sample period, and reproduction and sporulation occurred 1 month earlier. Also, in situ relative growth rates (RGRs) of plants differed significantly and were correlated with different climatic factors (sunshine, day length, irradiance, rainfall, seawater temperature, and intertidal temperatures), suggesting that plants were affected by two different microhabitats. At one site, blades were more exposed to wave action, sunshine, and extreme minimum temperatures, while at the other site, blades were more protected in winter, spring, and early summer. In culture, RGRs of blades from the second site were higher than RGRs of blades from the first site under short days, corroborating the field results and suggesting a degree of phenotypic differentiation between the two populations. However, there were no sequence divergences of the RUBISCO spacer between strains of the two P. linearis populations.