Bahama Islands Research Articles

Competition among mangrove oomycotes, and between oomycotes and other microbes

AME Aquatic Microbial Ecology Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials AME 12:21-28 (1997) - doi:10.3354/ame012021 Competition among mangrove oomycotes, and between oomycotes and other microbes Newell SY, Fell JW Competition experiments were performed using precolonized leaves or leaf disks of red mangrove Rhizophora mangle with: (1) disks containing pure cultures of single species of marine true fungi or species of Halophytophthora (the principal genus of marine oomycotes); and (2) leaves bearing bacterial films. Preoccupied leaves were exposed to natural microflorae in mangrove creeks at 2 Cays in the Bahama Islands, or placed in laboratory seawater enclosures wherein pairs of halophytophthoras were given equivalent opportunity to occupy fresh leaf material. The ubiquitous coastal-marine oomycote H. vesicula was found to be an able competitor versus true fungi and versus other halophytophthoras. Against other halophytophthoras, this was true for both primary and secondary resource capture. The one exception among the fungi was a species (Dendryphiella salina) common in decaying drift material in high-intertidal zones. H. spinosa was a weak competitor with true fungi and with H. vesicula, though it was not displaced by H. vesicula, and H. spinosa could depress the frequency of H. vesicula occupation when H. spinosa was well established. H. bahamensis did not routinely form sporangia, preventing identification and firm conclusions regarding competitiveness, other than that it could not block H. vesicula, but could block H. spinosa from entering its occupied arenas. When bacterial films were present on leaves prior to access by halophytophthoras, the occupation frequency of halophytophthoras was sharply depressed (by about 70 to 90% with 48 h bacterial films), including for H. vesicula, implying that in some types or parts of mangrove systems, submerged-leaf decomposition may sustain low levels of participation by halophytophthoras. Oomycotes · Halophytophthora · Fungi · Bacteria · Competition · Mangrove · Rhizophora Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in AME Vol. 12, No. 1. Publication date: January 30, 1997 Print ISSN: 0948-3055; Online ISSN: 1616-1564 Copyright © 1997 Inter-Research.

Geochemical and Physical Controls on Vadose Zone Hydrology of Holocene Carbonate Sands, Grand Bahama Island

This paper explores the relationship between vadose zone hydrology and geochemical changes in mixed mineralogy carbonate sands from a Bahamian coastal dune of Holocene age. Cores were taken from two sites: at site A, a shallow humic Entisol is developed beneath open scrub vegetation, while at site B a deeper, more organic-rich Inceptisol has formed beneath a mature hardwood coppice. X-ray diffraction analysis reveals significant contrasts in mineralogy both within and between the two sites, with partial stabilization of high-Mg calcite and aragonite, to low-Mg calcite. Stabilization is greater at site B, and is accompanied by a significant increase in total porosity. Diagenetic changes in pore-size distribution have implications for residence times of percolating water, as determined using measurements of moisture retention characteristics using pressure plate apparatus, and hydrological models of unsaturated zone moisture flux. The diagenetically more mature sands from site B have a 50–100 per cent higher moisture retention, although unsaturated hydraulic conductivity is also higher, particularly at greater suctions. The increase in water retention is likely to enhance further rates of mineral-controlled reactions, while development of an organic-rich soil also enhances the geochemical drive for dissolution. Carbonate diagenesis thus appears to be strongly linked to vadose zone hydrology, and the interactions identified here have important consequences for the nature and long-term rates of mineral stabilization. © 1997 by John Wiley & Sons, Ltd.

The long-horned beetles of south Florida (Cerambycidae: Coleoptera): biogeography and relationships with the Bahama Islands and Cuba

South Florida is a floral and faunal transition zone between the Nearctic region and the West Indian part of the Neotropical region. Ninety-one species of Cerambycidae are known from the south Florida mainland and 53 species of Cerambycidae from the Florida Keys. The cerambycid fauna of south Florida is about equally of Neotropical (53%) and Nearctic origin (47%). Since the Florida Keys were entirely submerged several times in the Pliocene and Pleistocene epochs, the present cerambycid fauna is predominantly the result of late Pleistocene – Holocene overland dispersal from south-central Florida and overwater dispersal from the West Indies (Bahama Islands and Cuba). Species–area and species–distance relationships for the islands form significant regression lines as predicted by the equilibrium theory of island biogeography. 'The presence of a "distance effect" is surprising, since it is usually considered that only during the past 10 000 years has the southern tip of the Florida peninsula been fragmented into the present-day islands of the Keys by a rising sea level. An alternative geological scenario, supported by this study, suggests that the present islands of the Keys have appeared as the sea level fell only within the past 6000 years, and the fauna is a more recently derived one.

Carbonate petrography as an indicator of climate and sea‐level changes: new data from Bahamian Quaternary units

ABSTRACTCoeval stratigraphic units of similar petrology occur throughout the northern Bahamas islands. The petrographic composition of these limestones provides clues about regional sea level and climate changes during the late Quaternary. At least eight fossil shoreline units, which are linked to transgressive episodes between the middle Pleistocene and the late Holocene, are recognized in the Bahamas. The petrographic composition of these units is either dominated by ooids and peloids or by bioclasts. Sedimentological observations demonstrate that oolitic‐peloidal units were formed when sea level was higher than today, whereas skeletal units were deposited at or below modern ordnance datum. Skeletal units may reflect times of partial, or modest platform flooding, when the bulk of sediments brought to islands originates from bank‐margin reefs. In contrast, oolitic‐peloidal units correspond to major flooding events and active water circulation on the bank top. Cement fabrics further show that the early diagenesis of oolitic units took place during warm and humid climatic conditions, whereas skeletal rock bodies underwent subaerial diagenesis during drier climatic conditions characterized by marked seasonal changes. This example from the Bahamas suggests that compositional analysis of limestone from fossil carbonate platforms could be used for resolving ancient climate and sea‐level changes.

Percutaneous closure of an arteriovenous iliac fistula with a Cragg endoluminal graft.

Placement of stents in the iliac arteries has become established in interventional radiology [1]. Conventional stents, such as the Palmaz, Wall, and Strecker stents, are porous and are not suitable for treating arteniovenous fistulas. In 1983, a technique for percutaneous vascular graft placement with closed-wall stents was introduced [2, 3], and in 1993, a new system for endoluminal grafting, the Cnagg Endopro System 1 (Mintec, Bahama Islands), became available [4]. In this report, we describe the first successful pencutaneous treatment of a large arteniovenous fistula between the iliac artery and vein with the Cnagg Endopro System 1.

Economic Analysis of a Commercial-Scale Recirculating, Brackish Water Hatchery for Florida Red Tilapia

An economic analysis was performed on a commercial- scale, recirculating, brackish water hatchery for Florida red tilapia located on Lee Stocking Island (LSI), a privately-owned island in the Bahamas, using actual design criteria and production data collected from 1987-1992. Results were compared with a hypothetical facility based in the city of Freeport, on Grand Bahama Island, Bahamas. At annual production levels of 1.0-2.5 million sex-reversed fry, breakeven prices ranged from $0.16-0.07/fry at LSI and from $0.14-0.06/fry at Freeport. Salaries and benefits represented the largest fixed costs, accounting for 34.6% and 39.1% of annual production costs at LSI and Freeport, respectively. Air-freight shipping to Miami, Florida represented the largest variable cost at both locations, with private air charter from LSI accounting for 16% of the annual operating cost and commercial air freight from Freeport accounting for 6.1% of the total annual costs. At annual sales of 2 million sex-reversed fry, internal ra...

Two new Halophytophthora species, H. tartarea and H. masteri, from intertidal decomposing leaves in saltmarsh and mangrove regions

Two new pythiaceous fungi were obtained from decaying leaves submerged in saltmarsh environments of the east coast of the U.S.A., or fringing mangroves in the Bahama Islands, and are described here asHalophytophthora tartarea andH. masteri. The two species have superficially similar zoosporangia whose dehiscence tubes have ragged-looking apices. However, differences in fine structures and development of the dehiscence tube and plug, characteristics of the dehiscence plugs, and presence or absence of vesicles clearly distinguish the two species.Halophytophthora masteri is the only species ofHalophytophthora that has a zoospore release mechanism involving both an extruded plug and a vesicle. Cultural properties concerning growth and asexual reproduction at various salinities and temperatures are also different between the two, probably reflecting adaptation to their respective habitats. Though zoospore release inH. masteri occurs spontaneously from mature zoosporangia, it is remarkably enhanced inH. tartarea and alsoH. masteri by mildly dehydrating mature zoosporangia followed by rewetting with seawater, which suggests a possible relation between the asexual reproduction of these oomycetes and the tidal rhythm in their natural habitats.

Late pleistocene sea level change in the Bahamas from mass spectrometric U-series dating of submerged speleothem

The dating of sea level events by a method independent of orbital tuning techniques and the marine foraminiferal isotopic record provides a test of both the dating of the marine record and the strength and nature of the relationship between climatic change, sea level change and Milankovitch cycles. Dating of fossil corals and submerged speleothem provides such independent information. Results of thermal ionization mass spectrometric U-series dating on layers of flowstone speleothem from Lucayan Caverns, Grand Bahama Island indicate that multiple sea level events have passed through a depth of −10 to −15 m below modern sea level during the last 300,000 years. These data are used to constrain the magnitude and timing of sea-level fluctuations during the late Pleistocene. The new sea level curve constructed from these data correlates closely with the marine isotopic record: sea level peaks occurred at around 233, 215, 125 and 100 ka BP. There is no evidence at the depth from which this speleothem was retrieved of any high sea stands at 195 or 80 ka corresponding to the foraminiferal 7a and 5a oxygen isotope peaks. There is also no evidence of a double rise around the 125 ka (5e) peak, although such an oscillation could have occurred above −10 m leaving no record in the Lucayan Caverns speleothem.

DODECALANA YAGERAE, NEW GENUS, NEW SPECIES, A TROGLOBITIC MARINE CIROLANID ISOPOD FROM GRAND BAHAMA ISLAND, BAHAMAS

ABSTRACT The troglobitic cirolanid isopod Dodecalana yagerae, new genus, new species, is described from marine caves on Grand Bahama Island, Bahamas. Distinctive characteristics include long projections on pereiopods 1-3, setae on pleopod endopods 1-5, absence of seventh pair of legs, and absence of retinacula on maxillipedal endites. Comparisons are made to other troglobitic cirolanids, especially to Bahalana. Patterns of evolution are suggested.

Daily rhythm of O2-evolution in the cyanobacterium Trichodesmium thiebautii under natural and constant conditions

The rate of oxygen evolution by the tropical marine cyanobacterium Trichodesmium thiebautii was recorded at different times during the day in samples collected in 1992 from the Bahama Islands and the NE Caribbean Sea. This cyanobacterium is unique in that it is the only non-heterocystous diazotroph capable of N2-fixation in daylight. Oxygen evolution was measured under conditions of natural day/night (LD, N=50), constant light (LL, N=14), and constant dark (DD, N=2×14). Photosynthesis vs intensity (P-I) relationships were calculated at various times of day, and the following parameters were used for further evaluation: photosynthesic capacity (Pmax, 66 to 91 mg O2 mg chl a-1 h-1), initial slope of the P-I curve (α, 0.23 to 0.27), dark respiration (R, 12 to 27 mg O2 mg chl a-1 h-1), and the intensity at which O2 consumption is compensated by O2 production (Ic, 78 to 160 μEm-2 s-1). All means showed large standard deviations (for some parameters more than 200%). In some cases, these variations could be explained with a sinusoidal 24-h time course, but only the compensation point showed a significant daily variation (p≤0.001) in both LD and DD. The fact that the time course of Ic typical for natural conditions remains rhythmic under constant dark conditions strongly suggests a circadian regulation. Few circadian rhythms have been observed in prokaryotes, and this appears to be the first observation of such a rhythm in a cyanobacterium which fixes N2 in daytime.

Starfish saponins, 52. Chemical constituents from the starfish Echinaster brasiliensis.

This paper reports an analysis of the chemical constituents from the Caribbean starfish Echinaster brasiliensis collected at Grand Bahama Island. This species is completely devoid of cyclic steroidal glycosides, previously isolated from two species of the genus Echinaster in place of the more common penta- and hexa-glycoside steroidal sulfates ("asterosaponins"). Two typical "asterosaponins" and ten glycosides of polyhydroxysteroids were instead isolated in relatively large amounts from E. brasiliensis. The asterosaponins include the known marthasteroside A1 [1] and the new brasiliensoside [2], while the glycosides of polyhydroxysteroids include seven new compounds (six monoglycosides and one diglycoside). The known echinasteroside A, previously found in Echinaster sepositus and in the related Henricia laeviuscula (both belonging to the family Echinasteridae), and laeviusculosides C and I from H. laeviuscula were also isolated. Most of the glycosides from E. brasiliensis are 3-O-beta-xylopyranosides of delta 4-3 beta,6 beta,8,15 alpha,16 beta pentahydroxysteroid aglycones, having different side chains and sometimes a sulfate group at C-15, structural features which are typical of steroidal glycosides from starfishes of the family Echinasteridae. Continuing the analysis of the constituents of E. brasiliensis, we have also isolated a series of anthraquinones, known animal pigments found only in echinoderms and particularly in Crinoidea and in the Echinasteridae family of Asteroidea.

Computer Simulation of Larval Transport Through Tidal Channels: Role of Vertical Migration

A two-dimensional computer model is used to investigate the long-term net advective transport of larvae in tidal channels. Simulations are made over l-year time periods for Adderley Channel in the Exuma Cays of the Bahama Islands, and Aransas Pass on the Texas Gulf coast. Tidal conditions at these two locations are dominated by semi-diurnal and diurnal constituents, respectively. Larval transport is simulated by the product of the predicted tidal current and the larval concentration in each of five layers. The vertical distribution of larvae is a function of vertical migration, which acts to concentrate larvae in top and bottom layers, and turbulent diffusion, which tends to produce vertically uniform concentrations. The effect of turbulent mixing is inversely related to the vertical swimming ability of the larvae and reduces substantially the net transport of slower swimmers. Both light and tidal phase cued migrations are considered. Diel migration results in a distinct annual cycle in the transport of larvae, as diurnal tidal constituents cycle in and out of phase with light and dark conditions. However, little long-term net transport is indicated. Migration according to tidal phase produces a negligible annual cycle, but a substantial quasi-steady net transport of larvae is indicated for both study sites. In other simulations, non-tidal currents are introduced to represent freshwater outflow and low-frequency estuarine-shelf exchanges, and unspecified retention mechanisms are incorporated into the model. For these study sites, both non-tidal transport and larval retention dominate the effect of vertical migration.

The Longhorn beetles (Coleoptera Cerambycidae) of the Bahama Islands with an analysis of species-area relationships, distribution patterns, origin of the fauna and an annotated species list

A summary is presented of the 63 species of Cerambycidae known from the Bahamas Islands, based mainly on a collection made in 1987 on Andros Island, supplemented by new literature records and material from other islands and collections. The Andros Island collection represented nearly 50% (31 spp.) of the species known from the Bahamas, and increased the number of species known from Andros by over 70% (16 spp.). New records are also given for Eleuthera Island, Great Exuma, Man-o-war Cay, Crooked Islands, New Providence, San Salvador, Abaco, Booby Cay, South Bimini, Long Islands, Grand Bahama, Mayaguana, Ragged Islands, Rum Cay and Nurse Cay. Six species are new to the Bahamas and one species is a new record for the Caribbean region. Sixteen endemic species are present. Log species-log area relationships for the islands form a significant regression line as predicted by the equilibrium theory of island biogeography. Comparison of the distributions of Bahamian tree species and cerambycids is significant. It ...

The Relationship between Variations in the Gulf of Mexico Loop Current and Straits of Florida Volume Transport

Abstract Twelve years of monthly mean positions of the northern boundary of the Loop Current in the eastern Gulf of Mexico from satellite and in situ data have been compared with coincident 1977–1988 estimates of volume transport in the Straits of Florida in the subseasonal frequency band 15−1 to 5−1 cycles per month. Volume transport estimated from Cuba minus Florida sea level difference in this frequency band accounts for 69% of the variance in volume transport estimated from the Florida-Grand Bahama Island submarine cable. On average, the Loop Current has a dominant period of 11 months whereas the volume transport is dominated by annual spectral energy; little significant coherence squared occurs between them. The maximum northward penetration of the Loop Current occurs on average in winter when the volume transport is a minimum, but this is an artifact of the sampling epoch. This negative relationship is most pronounced for 1979–1981 when transport is characterized as unimodal, but for 1984–1985 and 1...

Caribbean Pine in Sustainable Tropical Forestry

The name Pinus caribaea was fust used by Morelet in 1851 to refer to a species of pine in southeastern United States whose range included northern Central America, the Bahama Islands and Cuba. Later this species was separated from those in Central America, the Bahama Islands and Cuba, and identified as Pinus elliotri Engelm. The species in Central America, the Bahama Islands and Cuba retained the name Pinus caribaea. Subsequently, Pinus caribaea was separated into three varieties: caribaea, bahamensis, and hondurensis. The hondurensis variety has been the most widely introduced in plantations in the tropical and subtropical regions of the world; it grows vigorously in the various climates of the tropics and fonns more than 80% of the world's plantations listed under Pinus caribaea. Unfortunately the species is associated with poor seed production outside its native range, and all regeneration methods adopted to grow the species have not been fully satisfactory except for regeneration from seed. Latitudina...

Status and conservation of parrots and parakeets in the Greater Antilles, Bahama Islands, and Cayman Islands: J. W. Wiley, Bird Conservation International, 1(3), 1991, pp 187–214

Status and conservation of parrots and parakeets in the Greater Antilles, Bahama Islands, and Cayman Islands: J. W. Wiley, Bird Conservation International, 1(3), 1991, pp 187–214

Rapid oxygen cycling in Trichodesmium thiebautii

Oxygen uptake and evolution were measured in Trichodesmium thiebautii trichomes with 18O membrane inlet mass spectrometry. Samples were collected in the vicinity of the Bahamas Islands and eastern Caribbean Sea. Trichodesmium exhibited high rates of oxygen uptake in the dark and in the light compared with previously studied cyanobacteria. Oxygen uptake in the dark averaged 23% of the maximum gross oxygen evolution rate and was suppressed minimally at low irradiances or after the addition of cyanide. Oxygen uptake in light increased between 50 and 200 µEinst m−2 s− 1 and was inhibited by 3‐(3,4‐)‐dichlorophenyl)‐1,1‐dimethylurea (DCMU), indicating Mehler reaction activity. I estimate that 48% of the total photosynthetic linear electron flow went to oxygen reduction at moderate but nonsaturating irradiances. Light compensation points ranged from 50 to 300 µEinst m−2 s−1 with values highest for midday samples. Rapid oxygen cycling may contribute to the protection of nitrogenase by reducing the oxygen tension within the cell or colony during oxygenic photosynthesis and by providing a mechanism (pseudocyclic photophosphorylation) for generating excess ATP for nitrogen fixation.

Ultrastructure of the ovary and oogenesis in the jellyfish Linuche unguiculata and Stomolophus meleagris, with a review of ovarian structure in the Scyphozoa

Ovarian structure and oogenesis has been examined in six scyphozoan species including the semaeostome Diplumularis antarctica Maas, 1908 (collected in 1987 in McMurdo Sound, Antarctic), the rhizostomes Cassiopea xamachana Bigelow, 1892 (collected in Belize in 1988), and Stomolophus meleagris L. Agassiz, 1862 (collected in Ft. Pierce Inlet in 1988), and the coronates Periphylla periphylla (Peron and Lesueur, 1810), Nausithoe atlantica Broch, 1914 (both collected in the Bahamas in 1988), and Linuche unguiculata (Schwartz, 1788) (collected in Nassau Harbor, Bahama Islands in 1989). Based on these findings and information on five other scyphozoan species from additional literature sources, at least two fundamentally different types of ovaries exist in the Scyphozoa. In semaeosotome and rhizostome species, oocytes develop in close association with specialized gastrodermal cells called trophocytes which may serve a nutritive function. However, coronate species lack trophocytes and oocytes develop freely in the mesoglea. The ovaries of S. meleagris and L. unguiculata are used as models to represent the ultrastructural events occurring during oogenesis in species having trophocytes and those lacking them, respectively. In both L. unguiculata and S. meleagris, the ovaries arise as evaginations of the gastrodermis in the floor of interradial pouches. Germ cells appear to originate from endodermally-derived gastrodermal cells and migrate into the mesoglea prior to vitellogenesis. In L. unguiculata, the oocytes develop freely within the mesoglea throughout vitellogenesis, while in S. meleagris each oocyte maintains contact with specialized gastrodermal cells called trophocytes. In the vitellogenic oocytes of both species, numerous invaginations of the oolemma result in the formation of intraooplasmic channels throughout the ooplasm. These channels are intimately associated with cisternae of rough endoplasmic reticulum and may play some role in yolk precursor uptake by substantially increasing the surface area of the oocyte. Vitellogenesis is similar in both species and involves the autosynthetic activity of the Golge complex and rough endoplasmic reticulum, and the heterosynthetic incorporation of yolk precursors through receptor-mediated endocytosis. However, in the oocytes of S. meleagris, the trophocytes probably play a role in the transfer of nutrients from the gastrovascular cavity to the oocyte. The present study suggests that scyphozoans were among the first metazoans to develop ovarian accessory cells during their reproductive evolution. The trophocyte-oocyte association observed in some scyphozoans is similar to but structurally less complex than the trophonema-oocyte association described from anthozoans. Scyphozoan ovarian morphology helps support the view that the Scyphozoa share a closer phylogenetic relationship with the Anthozoa than with the Hydrozoa.

Distribution and experimental responses to substrate of marine oomycetes ( Halophytophthora spp.) in mangrove ecosystems

Two marine oomycetes, Halophytophthora vesicula and Halophytophthora spinosa , were predominantly frequent (up to 100% and 80% respectively), on newly submerged leaves of red mangrove ( Rhizophora mangle ) near or within stands of mangroves on cays surrounding Exuma Sound, Bahama Islands. Outside of the mangrove tidal channels, H. vesicula (but not H. spinosa ) was most frequent (47–93%) on newly submerged leaves placed near naturally submerged, decaying leaves. Within a tidal channel in an extensive stand of mangroves (15 km 2 ), H. vesicula was more frequent (67–93%) than H. spinosa (7–40%). H. vesicula may compete better than H. spinosa for new substrate when there is a large zoospore source nearby, and vice versa when zoospores are rare and must travel several metres to new substrate. H. vesicula and H. spinosa selectively colonized mangrove leaves (45–100% frequency) as opposed to mangrove twigs (0–45%), other leaves (0–5%), or cellulose pads (0–5%). Protection of leaves from turbulent diffusion, but not from zoospore-swimming contact, reduced frequencies of both H. vesicula and H. spinosa by ca 75–100%, suggesting that chemotaxis toward leaves is, at most, of only very localized significance.

The Final Campaign of the American Revolution: Rise and Fall of the Spanish Bahamas.

During the War of the American Revolution-after the major actions on the continent had ended but before the projected French-Spanish invasion of Jamaicainfantry and artillery forces based in Cuba, with naval support from South Carolina, successfully attacked New Providence in the Bahama Islands. Spain occupied this colony for eleven months before a private army of British loyalists led by Colonel Andrew Deveaux dislodged its garrison in a campaign that the Paris settlement, negotiated several months before, had actually rendered unnecessary. In the present volume, James A. Lewis advances a carefully documented account of this littleknown but intriguing episode.