Life Sciences Commons^™

A Review Of Polylekithum Arnold, 1934 And Its Familial Affinities Using Morphological And Molecular Data, With Description Of Polylekithum Catahoulensis Sp Nov., Stephen S. Curran, Vasyl V. Tkach, Robin M. Overstreet

Faculty Publications

The type material of Polylekithum ictaluri, P. halli, and Maculifer chandleri was examined from the United States National Parasite Museum, and we determined that the material was conspecific, making P. halli and M. chandleri junior subjective synonyms of P. ictaluri. Polylekithum catahoulensis sp. nov. was described from material collected from catfishes at the Catahoula Wildlife Refuge, LaSalle Parish, Louisiana, USA, and compared with P. ictaluri collected from catfishes in Reelfoot Lake, Obion County, Tennessee, USA, and the Pearl River, Hancock County, Mississippi, USA. Polylekithum catahoulensis had smaller eggs (77–88 μm long by 51–63 μm wide vs. 94–108 μm by …

Red Tides In The Gulf Of Mexico: Where, When, And Why?, J. J. Walsh, J. K. Jolliff, B. P. Darrow, J. M. Lenes, S.P. Milroy, A. Remsen, D.A. Dieterle, K.L. Carder, F.R. Chen, F.R. Chen, G.A. Vargo, R.H. Weisberg, K.A. Fanning, F.E. Muller-Karger, E. Shinn, K.A. Steidinger, C.A. Heil, C.R. Tomas, J.S. Prospero, T.N. Lee, G.J. Kirkpatrick, T.E. Whitledge, D.A. Stockwell, T.A. Villareal, A.E. Jochens, P.S. Bontempi

Faculty Publications

Independent data from the Gulf of Mexico are used to develop and test the hypothesis that the same sequence of physical and ecological events each year allows the toxic dinoflagellate Karenia brevis to become dominant. A phosphorus-rich nutrient supply initiates phytoplankton succession, once deposition events of Saharan iron-rich dust allow Trichodesmium blooms to utilize ubiquitous dissolved nitrogen gas within otherwise nitrogen-poor sea water. They and the co-occurring K. brevis are positioned within the bottom Ekman layers, as a consequence of their similar diel vertical migration patterns on the middle shelf. Upon onshore upwelling of these near-bottom seed populations to CDOM-rich …

Effects Of Long-Term Hypoxia On Enzymes Of Carbohydrate Metabolism In The Gulf Killifish, Fundulus Grandis, Mery L. Mártinez, Christie Landry, Ryan Boehm, Steve Manning, Bernard B. Rees

Faculty Publications

The goal of the current study was to generate a comprehensive, multi-tissue perspective of the effects of chronic hypoxic exposure on carbohydrate metabolism in the Gulf killifish Fundulus grandis. Fish were held at approximately 1.3 mg l(-1) dissolved oxygen (similar to 3.6 kPa) for 4 weeks, after which maximal activities were measured for all glycolytic enzymes in four tissues (white skeletal muscle, liver, heart and brain), as well as for enzymes of glycogen metabolism (in muscle and liver) and gluconeogenesis (in liver). The specific activities of enzymes of glycolysis and glycogen metabolism were strongly suppressed by hypoxia in white skeletal …

Dissolved Gallium In The Northwest Pacific And The South And Central Atlantic Oceans: Implications For Aeolian Fe Input And A Reconsideration Of Profiles, Alan M. Shiller, Gautam Raj Bairamadgi

Faculty Publications

[1] The distribution of dissolved gallium, a less-reactive analogue of aluminum, has the potential to reveal information about the averaged dust input to the surface ocean and to complement studies using aluminum as a tracer. New data are presented here on the distribution of dissolved Ga, including six profiles in the south and central Atlantic as well as seven shallow and two deep profiles from the northwest Pacific. The Atlantic data allow for an estimate of Ga in Antarctic Bottom Water ( similar to 25 - 30 pmol kg(-1)) and show reasonably conservative behavior in deep waters. In the northwest …

Source And Transport Of Terrigenous Organic Matter In The Upper Yukon River: Evidence From Isotope (𝛿c-13, Δc-14, And 𝛿n-15) Composition Of Dissolved, Colloidal, And Particulate Phases, Laodong Guo, Robie W. Macdonald

Faculty Publications

Natural organic matter was collected from the upper Yukon River and size fractionated into the (LMW-DOC), colloidal (COC, 1 kDa to 0.45 mu m) and particulate organic carbon (POC, > 0.45 mu m) phases for characterization of elemental (C and N) and isotopic (C-13, C-14 and N-15) composition to examine their sources and transport. Concentrations of total organic carbon (TOC) decreased from 3010 mu M in mid-May to 608 mu M in September, accompanying an increase in river water delta O-18 from the snowmelt to summer and early fall. COC was the predominant OC species, comprising, on average, 63 +/- 8% …

Summer Transport Estimates Of The Kamchatka Current Derived As A Variational Inverse Of Hydrophysical And Surface Drifter Data, G.G. Panteleev, P. Stabeno, V.A. Luchin, Dmitri A. Nechaev, M. Ikeda

Faculty Publications

The quasistationary summer Bering Sea circulation is reconstructed as a variational inverse of the hydrographic and atmospheric climatologies, transport estimates through the Bering Strait, and surface drifter data. Our results indicate the splitting of the Kamchatka Current in the vicinity of the Shirshov Ridge. This branching is in agreement with independent ARGO drifter observations. It was also found, that transport of the Kamchatka Current gradually increases downstream from 14 Sv in the Olyutorsky Gulf to 24 Sv in the Kamchatka Strait, which is twice higher than previous estimates.

Vittatispora, A New Melanosporaceous Genus From Indian Soil, Preeti Chaudhary, Jinx Campbell, David L. Hawksworth, Kedarnath N. Sastry

Faculty Publications

Vittatispora coorgii gen. sp. nov., isolated from soil in India, is described and illustrated. The fungus has morphological characteristics of the genera Melanospora, Sphaerodes and Syspastospora. The most striking feature is the presence of a thick hyaline ridge along the vertical axis of the lemonshaped ascospores wall. Perithecia also have a long neck composed of adhering hyphae, similar to that of Syspatospora. Phylogenetic studies on the 28S rDNA indicate it is closely related to Melanospora and Sphaerodes and belongs in the Ceratostomataceae. The new genus is based on the distinctive morphology and phylogenetic analyses. The fungus grew in culture only …

Antiestrogens Inhibit Xenoestrogen-Induced Brain Aromatase Activity But Do Not Prevent Xenoestrogen-Induced Feminization In Japanese Medaka (Oryzias Latipes), Adam J. Kuhl, Marius Brouwer

Faculty Publications

In fish, exposure to estrogen or estrogen-mimicking chemicals (xenoestrogeus)during a critical period of development can irreversibly invert sex differentiation. In medaka, a male-to-female reversal upon exposure to a xenoestrogen is accompanied by an increase in brain aromatase expression and activity. However, whether this increase is the direct cause of sex reversal is unknown. In this study we further examined the role brain aromatase plays in genesis of developmental abnormalities in response to endocrine-disrupting chemicals (EDCs). Further, the effects of a mixture of apparent antagonistic environmentally relevant EDCs on development were examined to determine if their combined actions could lessen each …

Zonal Patterns Of Delta C-13, Delta N-15 And Po-210 In The Tropical And Subtropical North Pacific, Min Chen, Laodong Guo, Qiang Ma, Yusheng Qiu, Run Zhang, E Lv, Yipu Huang

Faculty Publications

Nitrogen fixation process may supply a significant fraction of bioavailable nitrogen to surface waters, increase the oceanic sequestration of atmospheric CO2, and alter the distribution of geochemical parameters. We report a zonal pattern of delta N-15 and delta C-13 in particulate organic matter (POM), and ratios of particulate Po-210 to dissolved Po-210 along a transect through the subtropical and tropical North Pacific. Both N-15 and Po-210 signals indicated an enhanced N-2 fixation in the northwestern subtropical North Pacific. The eastward decrease of N-2 fixation along this transect testified the role of aeolian Fe and P in controlling marine N-2 fixation. …

Benthic Nutrient Flux In A Small Estuary In Northwestern Florida (Usa), Guy T. Didonato, Emile M. Lores, Michael C. Murrell, Lisa M. Smith, Jane M. Caffrey

Gulf and Caribbean Research

Benthic nutrient fluxes of ammonium (NH₄⁺), nitrite/nitrate (NO₂^- + NO₃^-), phosphate (PO₄^-3), and dissolved silica (DSi) were measured in Escambia Bay, an estuary within the larger Pensacola Bay system of northwestern Florida (USA). Our study occurred during a severe drought which reduced riverine inputs to Escambia Bay. Laboratory incubations of field-collected cores were conducted on 8 dates between June and October 2000 to estimate nutrient flux, and cores were collected from locations exhibiting a range of sediment organic matter content. NH₄⁺ flux ranged from – 48.1 to …

Feeding Habits Of Common Snook, Centropomus Undecimalis, In Charlotte Harbor, Florida, David A. Blewett, Rebecca A. Hensley, Philip W. Stevens

Gulf and Caribbean Research

We examined the feeding habits, ontogenetic and seasonal diet variations, and predator size–prey size relationships of common snook, Centropomus undecimalis, in Charlotte Harbor, Florida, through stomach contents analysis. A total of 694 stomachs were extracted from common snook (300–882 mm standard length [SL]) during a 24-month period (March 2000–February 2002); 432 stomachs contained prey items. At least 37 prey taxa were identified, including 19 that had not been previously reported. Fishes made up 71% of the prey by number and 90% by weight. Three prey items made up almost 50% of the diet numerically—Lagodon rhomboides, Anchoa spp., …

Comparison Of Fish Assemblages And Water Quality In Two Marinas In The British Virgin Islands, Brian Gratwicke, Martin R. Speight

Gulf and Caribbean Research

Eutrophication is a widespread problem in tropical marine environments that leads to the increase of nutrients in a water body, usually nitrate and phosphate, and is usually associated with the discharge of untreated sewage, intensive farming or fertilizer-enriched agricultural runoff (Wu 1999). Common symptoms are increased N and P levels, increased macroalgal production in shallow areas, reduced dissolved oxygen, loss of seagrass and coral habitats and changes in the fish community (Hallock and Schlager 1986, Granelli et al. 1990, Valiela 1995, Hemminga and Duarte 2000). Direct chemical testing to establish pollution levels can be difficult because of sharp pollution gradients, …

Body Size Of The Endosymbiotic Pea Crab Tumidotheres Maculatus: Larger Hosts Hold Larger Crabs, Karen Kane, Gregory S. Farley

Gulf and Caribbean Research

The endosymbiotic pea crab, Tumidotheres maculatus, uses a broad range of host taxa, including several bivalve species, in the northern Gulf of Mexico. Because shelter size affects the size of other, free-living crab species, we hypothesized that pea crabs living in larger bivalve hosts should attain larger sizes. Crabs and hosts collected from 3 field sites in northern Florida show this trend. We examined crabs living in a large host, the pen shell Atrina rigida, and found them to be larger than pea crabs living in a small host, the bay scallop Argopecten irradians. Moreover, this trend …

Marionia Tedi Ev. Marcus, 1983 (Nudibranchia, Tritoniidae) In The Gulf Of Mexico: First Record Of An Opisthobranch Mollusk From Hydrocarbon Cold Seeps, Angel Valdes

Gulf and Caribbean Research

Cold seeps in the Gulf of Mexico contain relatively diverse molluscan assemblages primarily composed of species that support chemoautotrophic symbionts, such as vesicomyid and mytilid bivalves, but also numerous species of shelled gastropods, bivalves, monoplacophorans, and polyplacophorans (Cordes 2004).

Recent exploration of hydrocarbon seep sites in the Mississippi Canyon and the Vioska Knoll revealed the presence of an unidentified species of nudibranch. The present paper describes the single specimen collected, which constitutes the first published record of an opisthobranch mollusk from a cold seep. The material examined is deposited at the Field Museum of Natural History (FMNH).

New Records For Cubanocuma Gutzui Băcescu And Muradian, 1977 (Crustacea: Cumacea: Nannastacidae) From The Western Atlantic, Richard W. Heard, Joel W. Martin, Thomas J. Hansknecht, Donald B. Cadien

Gulf and Caribbean Research

Because the original description and many subsequent records for Cubanocuma gutzui have appeared in a Romanian journal, Travaux du Muséum d’Histoire naturelle “Grigore Antipa,” which has limited distribution in the west, many workers studying tropical western Atlantic crustaceans still remain unaware of both the genus and species. Also, the species may have gone unrecognized (recorded as an odd specimen of Campylaspis, for instance) or may have been overlooked because of its small size. As part of an ongoing survey of the marine invertebrates of Guana Island, British Virgin Islands (BVI) (led by T.L. Zimmerman and J.W. Martin), numerous specimens …

Baseline Mapping Of Phragmites Australis (Common Reed) In Three Coastal Mississippi Estuarine Basins, Mark S. Peterson, Melissa L. Partyka

Faculty Publications

Over the last two decades, the northern Gulf of Mexico has undergone tremendous growth and development that has resulted in extensive and ongoing habitat modification. We had the opportunity to survey the main channels and bayous of three coastal estuarine basins for the presence and coverage of the invasive Phragmites australis (common reed). The occurrence and area of P. australis was highly variable among the lower Pascagoula River, Back Bay of Biloxi, and St. Louis Bay basins, with the largest amount of coverage (0.489 km(2)) found within the lower Pascagoula River basin and the smallest in Back Bay of Biloxi …