Michael J. Wynne

Introduction to the algae: structure and reproduction

Very comprehensive text for physiology (algae) and/or limnology (freshwater biology) courses at the junior/senior/grad level.

A synoptic review of the classification of red algal genera a half century after Kylin's “Die Gattungen der Rhodophyceen”

Abstract Classification of the red algae (Rhodoplantae) has undergone significant change since the seminal work of Harald Kylin, “Die Gattungen der Rhodophyceen,” a half century ago. The number of genera has nearly doubled over this time period, at least in part due to recent molecular comparative work. Information gleaned from gene-sequencing analyses has resulted in a red algal classification that reflects a more accurate phylogenetic framework than that based solely on morphological data. This paper tabulates the known 834 genera of red algae today with taxonomic synonyms and literature references reflecting the great change over fifty years.

THE FINE STRUCTURE OF THE NUCLEUS AND NUCLEAR ASSOCIATIONS OF DEVELOPING CARPOSPORANGIA IN POLYSIPHONIA NOVAE-ANGLIAE (RHODOPHYTA) 1

A high degree of activity of the nuclei in the developing carposporangia of the red alga Polysiphonia novae‐angliae Taylor is described. Profiles of the nucleus are greatly convoluted, resulting in a much increased surface area. Regions where endoplasmic reticulum substitutes for the nuclear envelope are frequently observed. Various cytoplasmic reserves are associated with the nucleus during carposporangium maturation. Lipid bodies, fibrillar bodies, and striated vesicles (or cylindrical bodies) may occur within the nucleoplasm beneath areas of the nuclear envelope substituted by ER. Granules of Floridean starch are observed in proximity to the outer surface of these same areas as well as the nuclear membrane. The homologous nature of the nuclear envelope with the ER is stressed. The role of the nucleus as being actively involved in the synthesis of materials is suggested.

ENDOCYTOSIS OF MICROCYSTIS AERUGINOSA BY OCHROMONAS DANICA1

Ochromonas danica Prings., a chrysomonad alga which demonstrates a high degree of nutritional versatility, is capable of feeding on the toxic blue‐green alga Microcystis aeruginosa Kuetz. In this paper light microscopic, electron microscopic, and cytochemical examinations of endocytosis in O. danica are reported, with particular emphasis on the vicissitudes of endocytic and lysosomal activities during intra‐cellular digestion. An interpretation of the function of organelles associated with endocytosis is presented.

The Benthic Marine Algal Flora of the Sultanate of Oman: New Records

Floristic studies along the coast of the Sultanate of Oman, both on the northern Arabian Sea and on the Gulf of Oman, have resulted in the recognition of a number of new reports of algal species for this coastline. The publication of a catalogue of benthic marine algae of the Indian Ocean by Silva et al. (1996) has greatly facilitated the process of checking whether species have been reported for a given country bordering the Indian Ocean. The Sultanate of Oman has not received nearly the same degree of attention that has been directed toward the coastlines of other countries in the region, such as Pakistan, India, Somalia, and, to a lesser extent, Yemen. Yet a significant fact is that the Sultanate of Oman is a country with an area of over 300 000 km, approximately equivalent to that of the United Kingdom and Ireland combined, and has a coastline of 1800 km (Clarke et al. 1986). The relative paucity of literature on Omani seaweeds is striking, especially in light of the conspicuous growth of marine algae in the littoral zone during the summer monsoon. The coastline of Dhofar in southern Oman is greatly impacted by this seasonal monsoon, such as has been shown for the coast of adjacent Yemen (Ormond and Banaimoon 1994), at which time constant winds bring about much wave action, upwelling, and elevated nutrient levels (Savidge et al. 1990). Several technical reports on the ecology of the kelp and Sargasswn beds in the Dhofar region have been published (Anon. 1988, Barratt et al. 1984, 1986). Earlier efforts toward identifying the benthic marine algae of the northern Arabian Sea include papers by B0rgesen (1934), who treated collections from Karachi (Pakistan) and Dwarka (India), and Newton (1953), who listed some species based on collections made at the Al Halaaniyaat Islands (formerly the Kuria Muria Islands) on the southern coast of Oman. A technical report by Mardela International (Anon. 1975) compiled a detailed survey of seaweed resources from the standpoint of potential economic value for the entire coastline of Oman; algal taxa, however, were categorized only to the generic level. Cordero (1993) published a list of about 50 taxa of marine algae (many merely to genus level) for the Muscat area, but this paper was not included by Silva et al (1996). Therefore, our list includes names of some taxa that have been reported by Cordero (1993) but not in Silva et al. (1996) tally for Oman. A species of Sargassum, S. zanardinii Schiffn., with a distribution restricted to Oman, Pakistan, and Yemen, was segregated into its own new genus, Sargassopsis, by Nizamuddin et al. (1993). This name, however, proved to be a later homonym and thus an illegitimate name, and Silva (in Silva et al 1996) replaced it with the name Nizamuddinia.

Hypoglossum caloglossoides sp. nov. (Delesseriaceae, Rhodophyta) from Lord Howe Island, South Pacific

An alga superficially resembling the genus Caloglossa in its habit is a previously undescribed species of Hypoglossum (Delesseriaceae, Rhodophyta). Hypoglossum caloglossoides sp. nov. occurs at Lord Howe Island in the South Pacific at a depth of 11 m, where it grows as a creeping system over coral. Additional material of this alga was found in collections from Samoa (misidentified as Calaglossa vieillardii) and from the Southern Marshall Islands (misidentified as C. leprieurii var. pygmaea). Observations are made on tetrasporangial, male and female specimens, and the relationships of this new species with other members of the genus and with Caloglossa are discussed.

Further connections between the benthic marine algal floras of the northern Arabian Sea and Japan

Identifications made on some recent collections of benthic marine algae from the Sultanate of Oman, northern Arabian Sea, have revealed several new records for this region. A total of eight species, representing five species of Rhodophyceae, two species of Phaeophyceae, and a single species each of Chlorophyceae, are newly reported for Oman. Of particular interest is the fact that these species represent new records for the Indian Ocean, some of which had previously been known from Japan and environs.

Delineation of the Genera Struvea Bonder and Phyllodictyon J. E. Gray (Cladophorales, Chlorophyta)

Plants of the stalked, net‐forming green alga Struvea plumosa Sender, the type species of the genus Struvea, divide segregatively at every stage of their multicellular differentiation. The segregative process results in virtually simultaneous internal cleavage of the cytoplasts of parent axes or laterals into uniseriate series of nearly identically sized daughter cells m which intercalary cross‐wall formation never takes place. Several branch orders result through a repeated process by which each daughter cell produces a pair of opposite protrusions at its distal end; the protruded arms subsequently undergo segregative divisions themselves after reaching a sufficient length. Struvea elegans Børgesen is seemingly the only other member of the genus in which the thallus divides by this segregative process. The remaining species appear to lack segregative cell division, their septation resulting from non‐synchronous, centripetal wall ingrowths that divide parent cells into more or less equal halves. Intercalary cell divisions are common, this process being easily seen in the most widely distributed member of the genus, Struvea anastomosans (Harv.) Pice, et Grunov ex Pice. Phyllodictyon J. E. Gray, based on Phyllodictyon putcherrimum. is currently considered a synonym of Struvea but should be reinstated to accommodate those former species of Struvea that have Cladophoratype. as opposed to segregative, cell division. Although the two genera thus differ substantially in their modes of cytokinesis and are assumed to represent independent developmental lines, both Struvea and Phyllodictyon are assigned to the Cladophorales on the basis of molecular studies by others showing that recognition of the separate order Siphonocladales renders the Cladophorales paraphyletic.

The genus Hypoglossum Kützing (Delesseriaceae, Rhodophyta) in the tropical western Atlantic, including H. anomalum sp. nov.

Observations are made on the occurrence and distribution of the red algal genus Hypoglossum Kützing (Delesseriaceae, Ceramiales) in the tropical western Atlantic. In addition to the type of the genus, H. hypoglossoides (Stackh.) Coll. & Herv., three other species are reported: H. anomalum sp. nov., H. involvens (Harv.) J. Ag., and H. tenuifolium (Harv.) J. Ag. A key is presented to distinguish these four species. The newly described species, H. anomalum, is like other species in the genus in that its branches arise endogenously from the primary axial row but it is unique in that the branches emerge from the parent blade at some point between the midline and the margin of the blade. The new species is reported from Puerto Rico and Florida.

Culture studies of Pacific coast Phaeophyceae

SummarySyringoderma abyssicola, the little known type species of an apparently dictyotalean genus, is reported on after field and culture observations. Fungal infestations of the genus Eurychasma produce conspicuous sporangia which give the appearance of reproductive structures of the alga itself, and perhaps SETCHELL and GARDNER observed these when they figured « aplanosporangia » for this species. Sporangia belonging to the alga itself have not been seen. The genus may be better placed in the Sphacelariales than with the Dictyotales.Coilodesme bulligera and C. fucicola (Punctariaceae) both demonstrated in culture direct development of new saccate thalli from spores of unilocular sporangia. In Coilodesme califomica, Saundersella simplex, and Halorhipis winstonii plethysmothalli which repeated themselves were obtained. These microscopic phases formed plurilocular and unilocular organs in C. califonica and S. simplex. The alga that has been called Stictyosiphon tortilis in California and Washington lacks t...