N2 fixation in the rhizosphere of Thalassia testudinum

1980 ◽  
Vol 26 (8) ◽  
pp. 998-1005 ◽  
Author(s):  
Douglas G. Capone ◽  
Barrie F. Taylor
Keyword(s):  
Organic Compounds ◽  
Seasonal Variations ◽  
N2 Fixation ◽  
Nitrogenase Activity ◽  
Late Summer ◽  
Thalassia Testudinum ◽  
South Florida ◽  
Biscayne Bay ◽  
The Bahamas ◽  
Lag Period

N2 fixation (C2H2 reduction) associated with the roots, rhizomes, and sediments (rhizosphere cores) of the seagrass Thalassia testudinum was measured at sites in South Florida (Soldier Key, Biscayne Bay) and the Bahamas (Bimini Harbor). Rates of C2H2 reduction were higher in anaerobic than in aerobic assays and were linear for several hours after an initial lag period of 1–2 h. Nitrogenase activity was proportional to the weight of rhizomes plus roots but showed no correlation with the total weight of the rhizosphere cores. C2H2 reduction occurred to depths of at least 30 cm but the majority (>85%) of the activity was in the 0- to 20-cm fraction; also the ratio of activities for the 0- to 10- and 10- to 20-cm depths was about 2:1. Most investigations were carried out using anaerobic assays of the 0- to 10-cm fractions and rates calculated for the period of 3–6 h after adding C2H2. These rates were not stimulated by organic compounds (glucose, lactate, succinate) but were approximately halved by a decrease in temperature of 10 °C. In a seasonal study at Soldier Key the rates of N2 fixation varied about 20-fold with maximal rates in late summer and minimal rates in winter (January). On a diurnal basis, C2H2 reduction increased in the morning but was depressed in midafternoon, probably due to O2 buildup in the rhizosphere. Daily rates of N2 fixation, during the summer months of 1975–1978, varied between 5 and 24 mg N m−2 and the estimated annual rates of N2 fixation were 10–50 kg N ha−1, taking into account seasonal variations and activities to a depth of 20 cm.

Estimating Nitrogenase Activity of Faba Bean (Vicia faba) by Acetylene Reduction (Ar) Assay

1990 ◽  
Vol 17 (5) ◽  
pp. 489 ◽  
Author(s):  
Herdina ◽  
JH Silsbury
Keyword(s):  
Diurnal Variation ◽  
Vicia Faba ◽  
Faba Bean ◽  
Closed System ◽  
N2 Fixation ◽  
Acetylene Reduction ◽  
Nitrogenase Activity ◽  
Electron Flow ◽  
Specific Rate ◽  
Rooting Medium

Methods of conducting acetylene reduction (AR) assay were appraised for estimating the nitrogenase activity of nodules of faba bean (Vicia faba L.). Factors considered were: (i) disturbance of plants when removing the rooting medium; (ii) assay temperature; (iii) the use of whole plants rather than detached, nodulated roots; (iv) diurnal variation in nodule activity; and (v) a decline in C2H4 production after exposure to C2H2. Plants growing in jars of 'oil dry' (calcined clay) had the same AR activity when assayed in situ in a closed system as when assayed after removal of the rooting medium. Assay temperatures of 12.5, 17.5 and 22.5°C influenced the specific rate of AR with the optimum at 17.5°C. Removal of the shoot resulted in a rapid decrease in AR activity in both vegetative and reproductive plants but the effect was much larger in the latter. AR and respiration by nodulated roots were closely linked and both varied markedly over a diurnal 12 h/12 h cycle. Since no fluctuation was found after nodules were detached, diurnal variation in the respiration of nodulated roots is attributed to change in nodule activity. Half of the dark respiration of nodulated roots was associated with respiration of the nodules and thus largely with N2 fixation. Since the AR assay provides no information on how electron flow in vivo is partitioned between reduction of N2 and reduction of protons, diurnal variation in hydrogen evolution (HE) in air and Ar/O2 in an open system was used to estimate this partitioning. Diurnal variation in apparent N2 fixation estimated in this manner was examined at a 'low' PPFD (300 μmol m-2 s-1) and at 'high' (1300 μmol m-2 s-1) to explore whether variation could be attributed to change in carbohydrate supply. Although HE in air and in Ar/O2 were both closely linked with the respiration of the nodulated root, apparent N2 fixation showed only a slight diurnal variation at 'low' light and almost none at 'high'. Vegetative plants showed no C2H2-induced decline in activity with exposure to C2H2 but reproductive plants did. This difference appears to be an age effect rather than attributable to flowering per se, since a decline occurred even when plants were kept vegetative by disbudding. A closed system for AR assay appears satisfactory for vegetative faba bean but such an assay over a 40-min period during the reproductive stage would underestimate nitrogenase activity by about 20%.

A quantitative study of the helminth parasites of the Newfoundland short-finned squid, Illex illecebrosus illecebrosus (LeSueur) (Cephalopoda:Decapoda)

1968 ◽  
Vol 46 (6) ◽  
pp. 1087-1093 ◽  
Author(s):  
Elizabeth L. Brown ◽  
William Threlfall
Keyword(s):  
Quantitative Study ◽  
Seasonal Variations ◽  
Standard Length ◽  
New Records ◽  
Parasite Burden ◽  
Late Summer ◽  
Eastern Coast ◽  
Published Data ◽  
Helminth Parasites ◽  
Host Animal

Ommastrephid squid of the subspecies Illex illecebrosus illecebrosus (LeSueur) were obtained during the late summer and early autumn of 1966 and 1967 from numerous areas around the eastern coast of the island of Newfoundland. Helminths of five genera were found, namely, Phyllobothrium sp. and Dinobothrium plicitum (both of which had previously been recorded from this host), Pelichnibothrium speciosum, Scolex polymorphus, and Nybelinia sp. The last three represent new records from this ommastrephid. The incidence of these parasites was tested for correlation with standard length and with sex of the host animal. Annual and seasonal variations in degree of infection were also noted. The greatest number of procercoids encountered were Dinobothrium plicitum. Degree of infection with helminths in 1966 and 1967 was similar (39%:40%) and contrary to earlier published data, infection by cestodes is not always directly correlated with mantle length. Any possible relations between sex of the squid and parasite burden are unclear.

Volatile organic compounds at a coastal site. 1. Seasonal variations

1982 ◽  
Vol 16 (1) ◽  
pp. 31-38 ◽  
Author(s):  
Philip M. Gschwend ◽  
Oliver C. Zafiriou ◽  
R. Fauzi C. Mantoura ◽  
Rene P. Schwarzenbach ◽  
Robert B. Gagosian
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Seasonal Variations ◽  
Coastal Site ◽  
Volatile Organic

Book Reviews

1994 ◽  
Vol 68 (1-2) ◽  
pp. 135-205
Author(s):  
Redactie KITLV
Keyword(s):  
New York ◽  
Cultural History ◽  
Economic History ◽  
West Indies ◽  
South Florida ◽  
The West ◽  
The Bahamas ◽  
University Of Florida ◽  
The People ◽  
The Caribbean

-Peter Hulme, Simon Gikandi, Writing in limbo: Modernism and Caribbean literature. Ithaca: Cornell University Press, 1992. x + 260 pp.-Charles V. Carnegie, Alistair Hennessy, Intellectuals in the twentieth-century Caribbean (Volume 1 - Spectre of the new class: The Commonwealth Caribbean). London: Macmillan, 1992. xvii 204 pp.-Nigel Rigby, Anne Walmsley, The Caribbean artists movement, 1966-1972: A literary and cultural history. London: New Beacon Books, 1992. xx + 356 pp.-Carl Pedersen, Tyrone Tillery, Claude McKay: A black poet's struggle for identity. Amherst: University of Massachusetts Press, 1992. xii + 235 pp.-Simone Dreyfus, Irving Rouse, The Tainos: Rise and decline of the people who greeted Columbus. New Haven: Yale University Press, 1992. xii + 211 pp.-Louis Allaire, Antonio M. Stevens-Arroyo, Cave of the Jagua: The mythological world of the Taino. Alburquerque: University of New Mexico Press, 1988. xiii + 282 pp.-Irving Rouse, William F. Keegan, The people who discovered Columbus: The prehistory of the Bahamas. Gainesville: University of Florida Press, 1992. xx + 279 pp.-Neil L. Whitehead, Philip P. Boucher, Cannibal encounters: Europeans and Island Caribs, 1492-1763. Baltimore: John Hopkins University Press, 1992. xii + 217 pp.-Peter Kloos, Kaliña, des amérindiens à Paris: Photographies du prince Roland. Présentées par Gérard Collomb. Paris: Créaphis, 1992. 119 pp.-Maureen Warner-Lewis, Alan Gregor Cobley ,The African-Caribbean connection: Historical and cultural perspectives. Bridgetown, Barbados: Department of History, University of the West Indies, Cave Hill, 1990. viii + 171 pp., Alvin Thompson (eds)-H. Hoetink, Jean-Luc Bonniol, La couleur comme maléfice: une illustration créole de la généalogie des 'Blancs' et des 'Noirs'. Paris: Albin Michel, 1992. 304 pp.-Michael Aceto, Richard Price ,Two evenings in Saramaka. Chicago and London: University of Chicago Press, 1991. xvi + 417 pp., Sally Price (eds)-Jorge Pérez Rolón, Vernon W. Boggs, Salsiology: Afro-Cuban music and the evolution of Salsa in New York City. New York: Greenwood, 1992. xvii + 387 pp.-Martin F. Murphy, Sherri Grasmuck ,Between two islands: Dominican international migration. Berkeley: University of California Press, 1991. xviii + 247 pp., Patricia R. Pessar (eds)-Rosario Espinal, Richard S. Hillman ,Distant neighbors in the Caribbean: The Dominican Republic and Jamaica in comparative perspective. New York: Praeger, 1992. xviii + 199 pp., Thomas D'Agostino (eds)-Svend E. Holsoe, Neville A.T. Hall, Slave society in the Danish West Indies: St. Thomas, St. John and St. Croix. Edited by B.W. Higman. Mona, Jamaica: University of the West Indies Press, 1992. xxiv + 287 pp.-Light Townsend Cummins, Francisco Morales Padrón, The journal of Don Francisco Saavedra de Sangronis 1780-1783. Translated by Aileen Moore Topping. Gainesville: University of Florida Press, 1989. xxxvii + 380 pp.-Francisco A. Scarano, Laird W. Bergad, Cuban rural society in the nineteenth century: The social and economic history of monoculture in Matanzas. Princeton: Princeton University Press, 1990. xxi + 425 pp.-Robert L. Paquette, Larry R. Jensen, Children of colonial despotism: Press, politics, and culture in Cuba, 1790-1840. Tampa: University of South Florida Press, 1988. xviii + 211 pp.-Robert L. Paquette, Anton L. Allahar, Class, politics, and sugar in colonial Cuba. Lewiston NY; The Edwin Mellen Press, 1990. xi + 217 pp.-Aline Helg, Josef Opatrny, U.S. Expansionism and Cuban annexationism in the 1850s. Prague: Charles University, 1990. 271 pp.-Rita Giacalone, Humberto García Muñiz ,Bibliografía militar del Caribe. Río Piedras PR: Centro de Investigaciones Históricas, Universidad de Puerto Rico, 1992. 177 pp., Betsaida Vélez Natal (eds)-Carlos E. Santiago, Irma Tirado de Alonso, Trade issues in the Caribbean. Philadelphia: Gordon & Breach, 1992. xv + 231 pp.-Drexel G. Woodson, Frantz Pratt, Haiti: Guide to the periodical literature in English, 1800-1990. Westport CT: Greenwood, 1991. xiv + 313 pp.-Gary Brana-Shute, Livio Sansone, Hangen boven de oceaan: het gewone overleven van Creoolse jongeren in Paramaribo. Amsterdam: Het Spinhuis, 1992. 58 pp.-Ronald Gill, Dolf Huijgers ,Landhuizen van Curacao en Bonaire. Amsterdam: Persimmons Management. 1991. 286 pp., Lucky Ezechiëls (eds)-Alex van Stipriaan, Waldo Heilbron, Colonial transformations and the decomposition of Dutch plantation slavery in Surinam. Amsterdam: Amsterdam centre for Caribbean studies (AWIC), University of Amsterdam, 1992. 133 pp.-Rosemarijn Hoefte, Bea Lalmahomed, Hindostaanse vrouwen: de geschiedenis van zes generaties. Utrecht: Jan van Arkel, 1992. 159 pp.-Aart G. Broek, Peter Hoefnagels ,Antilliaans spreekwoordenboek. Amsterdam: Thomas Rap, 1991. 92 pp., Shon Wé Hoogenbergen (eds)

scholarly journals Dynamic of decapod crustacean larvae on the entrance of Guanabara bay

2002 ◽  
Vol 45 (4) ◽  
pp. 491-498 ◽  
Author(s):  
Lohengrin Dias de Almeida Fernandes ◽  
Sérgio Luiz Costa Bonecker ◽  
Jean Louis Valentin
Keyword(s):  
Reproductive Cycle ◽  
Seasonal Variations ◽  
Coastal Waters ◽  
Decapod Crustacean ◽  
Late Summer ◽  
Late Winter ◽  
Guanabara Bay ◽  
Tidal Cycles ◽  
Decapod Larvae

In the present study, we observed seasonal variations in the density of decapod larvae as well as changes in density related to diurnal and tidal cycles. Among the decapod larvae collected, portunids and grapsids were the most abundant, especially during nocturnal ebb tides and near the surface. The same results were obtained in late winter (September) and late summer (March). These results demonstrated a flow of decapod larvae from Guanabara Bay to adjacent coastal waters. Luciferid (Lucifer faxoni) was the only group with high densities during flood tides and we suggest this is an evidence of L. faxoni larvae entering Guanabara Bay in late winter. Probably these changes in distribution of Lucifer faxoni among winter and summer were related to reproductive cycle in the bay. For the portunids, grapsids and ocypodids, a similar dispersion strategy was observed towards adjacent coastal waters in the surface during nocturnal ebb tides.

STREPSIPTERA OF SOUTH FLORIDA AND THE BAHAMAS WITH THE DESCRIPTION OF A NEW GENUS AND NEW SPECIES OF CORIOXENIDAE

1994 ◽  
Vol 126 (1) ◽  
pp. 125-134 ◽  
Author(s):  
Jeyaraney Kathirithamby ◽  
Stewart B. Peck
Keyword(s):  
West Indies ◽  
New Record ◽  
New Genus ◽  
The United States ◽  
South Florida ◽  
Fire Ants ◽  
The West ◽  
The Bahamas ◽  
Andros Island ◽  
First Time

AbstractEight species of Strepsiptera have been reported so far from Florida, but none from the Bahamas. This study reports five species from southern subtropical Florida, and one species from Andros Island, the Bahamas. Of these, Floridoxenos monroensis gen.nov., sp.nov. Kathirithamby and Peck (Corioxenidae: Corioxeninae) is described and added to the subfamily Corioxeninae based on the 4-segmented tarsi without claws; Strichotrema beckeri (Oliveira and Kogan) (Myrmecolacidae) of Brazil is reported from the United States for the first time; a second record for Elenchus koebelei Pierce (Elenchidae) from Florida is reported; and Caenocholax fenyesi Pierce (Myrmecolacidae) is a new record for Bahamas. This latter species is generally a widespread parasite of fire ants in the southern parts of North America, in the West Indies, and in the northern Neotropics.

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