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This article presents information related to ecology of Porphyra. Porphyra fallax occurs primarily on upper intertidal rock in moderately protected habitats as a winter-spring or spring-summer species. It becomes reproductive within a month or two of its appearance on the shore. Porphyra perforata occurs on moderately exposed to protected mid intertidal rock, between 1.5 and 3.5 m; it can occur epiphytically, primarily on Fucus. Porphyra perforata is found year round: young thalli are most abundant in fallwinter, and reproductive thalli are evident in late summer late fall.

The article presents studies of the green alga Kornmannia in British Columbia. At Triple Island, Kornmannia Z grew epiphytically on leaf margins of the vascular plant Phyllospadix, colonizing the tips of only a few plants in intertidal pools. Size and habit varied with the season. Early in March, many small cuneate blades were observed, arising directly from a few scattered, minute crust stages. As the season progressed to its peak in May, plants were more conspicuous. Usually, there was a single blade per basal crust, and saccate stages were readily observable.

The article discusses the reproduction in Porphyra maculosa. Margins of immature Porphyra maculose CONWAY blades collected from semi-sheltered coastal regions of British Columbia, Canada at the beginning of the growing season (April- May) consisted of packets of 2 or 4 aplanospores which developed into bipolar sporelings in culture. Mature blades did not develop aplanospores but produced spermatia and carpospores, which subsequently germinated into the conchocelis phase. This is the first observation of aplanospore production in young blades of a Porphyra species which reproduces sexually.

Polysiphonia subtilissima Mont. is reported for the first time from a freshwater environment. The presence of four pericentral cells, subdichotomous branching, apical trichoblasts and rhizoids arising from pericentral cells combined with a lack of cortication and reproductive cells is consistent with marine populations of this species. The range of filament length is 1.4-4.7 cm. Branch diameters are 38-76 μm and pericentral cell lengths are 58-125 μm. Batrachospermum heterocorticum sp. Nov. is distinguished primarily by a developmental change in cortical filaments from typical cylindrical cells (5.0-7.9 μm diam) in initial stages to enlarged, elliptical cells (12.9-24.1 μm diam) in mature axes. Another unique feature of this species is carpogonia with cylindrical, pedicellate trichogynes on straight carpogonial branches in mid to outer portions of lateral whorls. Other characteristics of B. heterocorticum include the following: olive-green color, 2-6 cm length, dichotomous to trichotomous fascicles in 4-7 tiers, 385-647 μm whorl diameters, 109-198 μm carpospore diameters and relatively small "chantransia" filaments. [ABSTRACT FROM AUTHOR]

Cellulose acetate of the hot water soluble polysaccharide extracts from whole filaments, as well as base., mid and tip segments, of marine asexual and sexual Bangia atropurpurea (Roth) C. Ag. yielded distinctive patterns which demonstrated that changes occur in the outer cell walls during sexual reproduction. Heterogeneity of the sulfated polysaccharide components isolated from outer cell walls was shown to be specifically related to sexual reproduction. Two components (Bands I and II) were detected in extracts from tips of sexual filaments, while only one (Band I) was present in the vegetative segments of all filaments and in asexual reproductive regions. The faster running component (Band II) was detected during the later stages of sexual development, prior to maturation. [ABSTRACT FROM AUTHOR]

Presents comparative studies on the cell walls of sexual and asexual Bangia atropurpurea. Histochemical study of the nature and distribution of acidic and neutral cell wall polysaccharides; Detection of neutral polysaccharides in the outer coating; Presence of acidic polysaccharides in the outer wall material; Change in the nature of the acidic component during sexual reproduction.

The fine structure of released, attached, and germinating carpospores of Porphyra variegata (Kjellm.) Hus is described. Adhesive vesicles, formed during sporogenesis and discharged upon settling of the spore, produced a layer of adhesive mucilage around the spore and filled a deep invagination on the spores ventral side. The mucilage layer was punctured by the emergence of a germ tube. Both spore and germ tube were lined by newly deposited cell wall. Germination was accompanied by vacuolation and starch mobilization. The morphological development of the sporeling was not noticeably influenced by the great variability of the timing, location, and orientation of septum formation. The attached carpospore possessed a plastid like that of gamatophyte cells: stellate with one large central pyrenoid and no peripheral encircling thylakoids. Cells of mature vegetative cells of the conchocelis had plastids that were elongate and parietal and had multiple pyrenoids and encircling thylakoids. Most stages in the transition between the two forms of plastids occurred during carpospore germination. [ABSTRACT FROM AUTHOR]

Chromosome number and morphology as well as reproductive seasonality were examined in Bangia populations collected from 88 sites along the British Columbia coasts. Sexual filaments were recorded at 35 sites and asexual filaments at 58. Four different types of Bangia were determined. These were characterized by reproductive state and chromosome number, as well as by their seasonality and range of distribution. A summer-fall three-chromosome sexual type occurred from approximately 50° N northward and a winter-spring four-chromosome sexual type had a northerly limit of approximately 54°N. extending to the southernmost areas of British Columbia. Two asexual types occurred, exhibiting little seasonality, six-chromosome populations at three southerly sites only. Karyograms were prepared for the four chromosomal types, assigning tentative centromere locations. Somatic chromosome pairing was reported for the first time in the Rhodophyta. [ABSTRACT FROM AUTHOR]

Discusses the ultrastructure of sperm from species in genera of Laminariales collected in the northeast Pacific Ocean. Uniqueness of the features in the brown algae; Presence of mitochondria and chloroplasts in the sperm; Support of the concept that Chorda is the most primitive member of the Laminariales.

Reports on a study by electron microscopy of zoospores of Laminariales collected in the northeast Pacific Ocean. Uniqueness of the zoospores in the brown algae; Presence of a distal whiplash portion on the mastigoneme-bearing anterior flagellum; Role of the microtubular cytoskeleton in maintaining the shape of the spore; Variation of the taxonomic significance in the ultrastructure of the vesicles.

In a survey of the distribution of Bangia atropurpurea (Roth) Ag. Along the north and east shorelines of the Laurentian Great Lakes, it was observed that this species was concentrated in the lower lakes. Asexual reproduction by monospore formation was the only form of reproduction in these populations. First generation germlings derived from these spores grew in a wide range of salinities from 1 to 26%, but the rate was inversely proportional to salinity. In addition, acclimation of parent plants to fresh-water or marine media prior to sporulation affected growth rates of first generation germlings placed into a series of salinities. By the second and third generation, germlings with a lineage of seawater showed a preference for the higher salinities, 19 and 26%. Plants collected in Lake Ontario exhibited no decline in photosynthetic rate as salinity was raised by 13% for 15 min. At 26% the rate was reduced by half and thylakoids were disrupted in the region of the pyreniod. On the other hand, third generation plants with a history of seawater attained maximum photosynthetic rates at 26% and contained a normal thylakoid organization. Three chromosomes were observed in these plants, which agrees with some of the previous findings for marine Bangia. Origins and taxonomic status of Bangia growing in the Great Lakes are discussed in light of these findings. [ABSTRACT FROM AUTHOR]

Twenty-one populations of Batrachospermum section Turfosa from North America were compared to nine type and two historically important specimens using multivariate morphometrics and image analysis. The protologues of six other infrageneric taxa were also compared. From this analysis, six species are recognized worldwide: B. desikacharyi Sankaran, B. gombakense Kumano et Ratnasabapathy, B. keratophytum Bory de Saint-Vincent [syn. B. vagum var. keratophytum (Bory de Saint-Vincent) Sirodot, B. gulbenkianum Reis, and B. suevorum Kützing nom. illeg.], B. sinense Jao, B. turfosum Bory de Saint-Vincent [syn. B. vagum (Roth) C. Agardh and B. vagum var. undulato-pedicellatum Kumano et Watanabe], and B. vogesiacum F. G. Schultz ex Skuja [syn. B. vagum var. flagelliforme Sirodot, B. flagelliforme (Sirodot) Necchi]. These species are distinguished on the basis of carposporophyte-bearing branch cortication, secondary fascicle development, monoecy or dioecy, presence of spermatangia on involucral filaments and monosporangia, and dimensions of trichogynes and carposporangia. Peripheral cortication has been previously used to separate species in this section, but we observed that this feature is quite widespread in the section. Presence of indeterminate gonimoblast filaments has been reported for some taxa in section Turfosa, but not such structures were seen in any of the specimen examined. Only B. keratophytum has been collected in North America, ranging from southwestern Greenland (64° N) to Louisiana (30° N). [ABSTRACT FROM AUTHOR]

Thirty-nine populations of Batrachospermum section Virescentia from North America were compared to eight Ope specimens and two historically important specimens using multivariate morphometrics and image analysis. From this analysis, two species ore recognized: B. heiminthosum Bory de Saint-Vincent (syn. B. bruziense Sirodot, B. graibussoniense Sirodot, B. sirodotii Skuja ex Flint, B. testale Sirodot, B. virgatum Sirodot nom. illeg., and B. viride Sirodot) and B. elegans Sirodot (syn. B. coerulescens Sirodot nom. illeg.). In B. helminthosum trichogynes are cylindrical to slightly club-shaped with few to no protuberances, whereas in B. elegans half to all of the trichogynes have one to three basal knobs or branches. None of the qualitative features previously used to separate species in this section were found to be of taxonomic value due to their universal presence; quantitative characteristics were highly variable and overlapped among specimens examined. Emended descriptions of both species are provided. Batrachospermum elegans was collected in northeastern US.A. and central Costa Rica, whereas B. helminthosum ranged from Nova Scotia to Louisiana and was collected in central Mexico, Costa Rica, and northwestern U.S.A. Batrachospermum julianum Arcangeli and B. transtaganum Reis, previously classified in section Virescentia, were observed to have twisted carpogonial branches and, therefore, should be placed in section Contorta. Sections Setacea and Virescentia of Batrachospermum differ in whorl size, ratio of carposporophyte height to whorl diameter, and trichogyne stalking, hence, we continue to recognize them as being distinct taxonomic entities as originally described. [ABSTRACT FROM AUTHOR]

Six populations of Batrachospermum section Setacea from North America were compared to eight type specimens using multivariate morphometrics and image analysis. From this analysis, four species in this section were distinguished worldwide: B. attrum (Hudson) Harvey [syn.B. gallaei Sirodol, B. orthostichum Skuja, B. sertularina (Bory) Bory]; B. diatyches Entwisle; B. androinvolucrum sp. nov.; and B. puiggarianum Grunow in Wittrock et Nordstedt (syn. B. angolense Welwitsch ex West et West, B. nigrescenes Welwitsch ex West et West). Two of these species were found in North America: B. attrum in California and Texas and B. androinvolucrum in British Columbia, Washington State, and Alabama. The new species, B. androinvolucrum, is distinguished by having spermatangia restricted to one-celled involucral bracts of the corpogonial branch [ABSTRACT FROM AUTHOR]