摘要:

SUMMARYCladophora glomerata(L.) Kütz. was the dominant attached alga in streams and along lake shores in southern Ontario. Maximum production occurred in summer and resulted from 2 short periods of intensive vegetative growth (June and September). Optimum habitat conditions consist of a firm substrate in shallow alkaline water. These conditions are provided by harbor facilities where man‐made structures supplement naturally occurring rock outcrops or cobble beaches and where nutrients are available from tributaries draining agricultural and urban land areas.Periodicity appears to be related to temperature; the interval between the 2 periods of intensive growth during warm weather decreases at successively more northern locations.Frequent observation ofCladophoragrowing at a single stream station revealed that variations in thallus morphology and relative cell dimensions ofC. glomerataare greater than has generally been recognized. These variations can be attributed to changes in environmental conditions and events in the annual life cycle of the al

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1967.tb04631.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARYResults of the study ofMonostroma fuscumfrom Son Juan Island, Washington, fully support the separation of the speciesM. fuscumfromMonostromasensu Wittrock into a taxon includingM. obscurum.It would appear from this and previous studies that theM. obscunim‐M. fuscumcomplex is clearly Ulvacean. The characteristics of the complex include (1) alternation of morphologically similar haploid and diploid generations; (2) production of biflagellate gametes and quadriflagellate zoospores; (3) a uniseriate form in early ontogeny; (4) thallus development progressing through a vesicular stage that, as a result of localized degenerative processes, opens at a size of less than I cm into a monostromatic blade; (5) cells elongated perpendicular to the plane of the thallus and with rotund‐truncate ends: (6) a single elongate plastid, thickened at the opposite poles of the cell and thinner in the equatorial region of the cell; (7) a thallus composed of cells with relatively inelastic walls; and (8) discrete discharge pores. The chromosome number ofMonostroma fuscumisn =9. The first division of the zoosporangium nucleus is meiosi

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1967.tb04632.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARYCells in a ‐wild population of a species belonging to the diatom germsMastogloiamay form frustules of 2 strikingly different morphologic types during their vegetative life cycle. Total conversion from coarsely structured morphologic form to a more finely structured form takes place during a single division; hence no inter gradations between the 2 forms are evident. Intact frustules with 1 valve of each type leave no reasonable doubt of the ability to make the chang

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1967.tb04633.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARYThe lunate cysts ofPyrocystis lunulahave a bioluminescent emission spectrum with a peak intensity of 477.5 ± 1 mμ. The light originates from the protoplasm in the center of the cysts. Six to eight hr after the cysts were placed in the dark, they produced 300 to 800 times more luminescence than controls maintained under constant, illumination. Plastids contract distally when the cysts are placed in the dark. If kept in the dark, the plastids contract distally and expand with a circadian rhythm persisting several days. At intensities of 2200 μm cm‐’or less, the plastids are expanded. The plastids are contracted into the central area of the cysts at light intensities of 4000 μw cm‐2and above. TheGymnodiniumstage of the life cycle is not biolu

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1967.tb04634.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARYFructose diphosphate aldolase activity was examined in acetone powders and cell‐free extracts of 15 photoautotrophically grown marine planktonic species belonging to 6 algal divisions as follows: Chlorophyta:Tetraselmis maculata, Dunaliella tertiolecta;Chrysophyta:Monochrysis lutheri, Isochrysis galbana, Prymnesium parvum, Coccolithus huxleyi;Bacillariophyta:Phaeodactylum tricornutum, Skeletonema costatum, Cyclotella nana;Cryptophyta:Cryptomonassp.,Rhodomonas lens, Hemiselmis virescens;Pyrrophyta:Amphidinium carteri;Cyanophyta:Anacystis marina, Agmenellum quadruplicatum.Indications of the types of aldolase (Rutter's classes) present in each alga were obtained from comparative studies of the effects of pH and of the following reagents on the activity: ethylenediamine tetraacetate, dithiothreitol, p‐chloromercuriphenyl sulfonate. Type I (higher plant‐animal type) aldolase only was indicated in the 2 chlorophytes, in I chrys‐ophyte(M. lutheri),and in 1 bacillariophyte(P. tricornutum),while the remaining algae appeared to contain either exclusively or principally Type II (bacterial‐fungal type) aldolase. The evolutionary implications of these findings are

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1967.tb04635.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARYThe diffusion coefficient of oxygen in stirred water in which the surface is unbroken is approximately 0.01 me cm.‐2min‐1atm‐1. Under these conditions, the modified Barcroft respirometer would not give valid results. Hence, it is recommended that this method be abandoned for studies of algal metab

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1967.tb04636.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARYThe similarity amongTetraspora, Chlorosaccus,andPhaeosphaera,belonging to the Chlorophyceae, Xanlhophyceae, and, Chrysophyceae, adds to the concept of parallel evolution among algal classes. Not only are all 3 genera characterized by colonial organization, nonmotile vegetative cells embedded in a gelatinous matrix, but the genera are also found in the same habitat. Further, the characteristic pseudocilia ofTetrasporacells are also found in colonics ofPhaeosphaera.Morphological features of pseudocilia ofTetrasporaand the nature of papillae inChlorosaccusare also presented.

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1967.tb04637.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARYGermination tests were conducted on 39 collections ofCharaoospores stored under 4 different conditions for periods of approximately 4 yr. In general, storage of dried oospores at low temperatures (3 C) provided the most satisfactory means for long‐term preservation of viable disseminules. Oospore germination zuas higher in light than in darkness. Effects of temperature and substrate upon germination were explored briefl

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1967.tb04638.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARYField and laboratory phycologists are still following different paths. This is regrettable because their labors supplement one another, and only by co‐operation can progress be achieve

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1967.tb04639.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARYA sexual cycle and a newly discovered mode of asexual reproduction by azygotes arc described forPediastrum simplex.In the sexual cycle isogametes from colony cells fuse in pairs, develop into zygotes, which grow and divide, producing motile cells which become angular polyeders. Polyeders may divide internally to form 4‐celled colonies, or they enlarge, cleave, and produce zoospores or nonmotile cells. Zoospores are released in vesicles, swarm, adhere to each other, and form, flat colonies I cell thick. The nonmotile cells adhere to each other, enlarge, break out of the polyeder, and become spheroidal colonies. In the asexual cycle, nonfusing gametes, and motile cells derived from colony cells, become 4‐spined azygotes which enlarge, divide internally, and release motile cells developing into polyeders. These polyeders develop further like those from zygo

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1967.tb04640.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY