摘要:

Abstract.The sinking rate (ψ) characteristics of a natural community of phytoplankton in the size range from 5 to 102 μn were determined. The following trends in ψ were observed: coc‐colithophorids>dinoflagellates>diatoms; large cells>small cells; attenuate shapesorganic‐loricate tintinnids. Dtnoflagellate swimming rates appear to be considerably greater than their sinki

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1983.tb00115.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Abstract.The cyanophyte(Cyanobaclerium)that causes black band disease of Atlantic reef corals is described under the namePhormidium corallyticum, new species (familyOscillatoriaceae), and its generic placement is discussed from the standpoint of the GEITLERian (classical) and Drouetsystems. Distinguishing characters include densely interwoven filaments that form a blackish mat and trichomes without significant cell wall constrictions, almost isodiametric cells (4.2 μm mean width, 4.0μm mean length) tapering end cells, and thin (0.1 μm or less) mucilaginous wall coating. Transmission electron microscopy shows typical cyanophyte cell walls, sheath, nucleoplasm, and cytoplasmic inclusions, but an unusual thylakoid of straight, and, as seen in cell cross section, radiating lamellae. The dark coloration is due to a high concentration of phycocyanin and some phycoerythrin. The species is similar toOscillatoria(=Phormidium) submembranacea, which differs in several morphological features and does not infect coral tissue. It is concluded thatPhormidiumshould be used for this and related species that have external mucilage but not the distinct sheath found inLyngb

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1983.tb00116.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Abstract.Tissue necrosis in reef corals is associated with the appearance of the cyanobacterium,Phormidium corallyticumRützler&Santavy, occurring in dense growths at the boundary between living and dead polyps. Studies at several sites in Florida, the Bahamas and Jamaica confirm the correlation between diseased tissues and the growth of this cyanobacterium. As a prerequisite to further investigations of the disease, its causes and control,Phormidium corallyticumwas isolated from necrotic areas on four separate species of reef corals, and grown in axenic culture using liquid and semisolid media. Data on its growth and nutrition in culture are presented. Growth rates appear to be sub‐optimal under the conditions used, suggesting possible nutrient deficiencies that could not be identified in this study.Phormidium corallyticumwill grow in the dark or with low light (20μEin m‐1s‐1) when the medium is supplemented with a range of organic co

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1983.tb00117.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Abstract.Some reef building corals in the western Atlantic are susceptible to an infection known as black band disease that is caused by the cyanophyte (cyanobacterium)Phormidium corallyticumRützler&Santavy. Field observations on the barrier reef of Belize and on reefs of the Bermuda platform indicate the disease is fairly common in susceptible species. Coral tissue destruction monitoredin situin Belize reveals rapid spreading rates and seasonality of the disease. Laboratory experiments confirm thatP. corallyticumis the etiologic agent and we speculate that a toxic exudate is the cause of histolysis observed in coral penetrated by the organism. Coral tissue is further broken down by a rapidly developing disease microcommunity, including bacteria and ciliate protozoans, identified with the aid of light, SEM, and TEM photomicrography. Study ofP. coraltyticumin culture away from its host coral reveals several ecological requirements, including dependence for optimal growth on yet unidentified organic substances contained in coral tissue. Healthy corals inoculated with various control organisms ‐ including the gliding bacteriumBeggiatoa, a filamentous chlorophyte, and six cyanophytes other thanP. corallyticum ‐did not develop the disease. Gorgonacean corals, too, can be artificially infected withP. corallyticum, but naturally occurring gorgonian bands are composed only of noninfectious cyanophyc

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1983.tb00118.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Abstract.The patterns and rates of feeding by the copepodAcartia hudsonicaand larvae of the polychaetePolydorasp. were investigated during the spring in an estuarine embayment. These dominant macrozooplankters fed upon the natural particulate assemblages (predominantly dino‐flagellates) spiked with the toxic dinoflagellateGonyaulax tamarensis. G. tamarensiswas ingested by both zooplankters, as wasHeterocapsa triquetra, the most abundant alternative food item. Ingestion rates generally increased as dinoflagellate concentrations increased, resulting in a relatively constant (and low) filtration rate for each grazer.Dinophysis acuminata, another dominant dinoflagellate, was essentially ungrazed. Thus, the zooplankters did not ingest one dinoflagellate and consumed others in proportion to their availability but at low rates. Based on these low rates and the small number ofA. hudsonicaobserved during the spring, we infer minima! grazing impact on a 1980G. tamarensisbloom. In contrast, the impact of polychaete larvae may have been substantial, since their extreme numerical abundance more than compensated for low filtration rates.In one instance, the tintinnidEutintinnus pectiniswas accidentally included in a grazing experiment. Our ingestion data demonstrate thatA. hudsonica, when presented with a combination of tintinnids and several species of phytoplankton(G. tamarensisandD. acuminata)ingested the tintinnids at high rates, in proportion to their high abundance. Since the nanoflagellateChroomonas amphioxeawas found within the loricae of many of the surviving tintinnids, this also provided a qualitative demonstration of the often‐hypothesized nanoplankton to tintinnid to copepod link in a marine food ch

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1983.tb00119.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Book reviewed in this article:Flemming, N. C.&J. Meincke(Eds.): Das Meer. Enzyklopädie der Meeres‐forschung und Meeresnutzung. Herder Verlag, Freiburg‐Basel‐WienAus dem Englischen von J. Kinzer&W. Brumm(The Atlas of the Oceans): Der große Kriiger Atlas der Ozeane. ‐ Wolfgang Krüger Verlag, Fra

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1983.tb00120.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY