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Comparison of condition indices in migratory passerines at a stopover site in coastal Louisiana Comparison of condition indices in migratory passerines at a stopover site in coastal Louisiana

We evaluated the utility of four nondestructive condition indices—body mass, body mass scaled by wing chord length, fat scoring, and total body electrical conductivity method (TOBEC)—as predictors of lipid levels in migrating Wood Thrushes (Hylocichla mustelina), Swainson's Thrushes (Catharus ustulatus), and Summer Tanagers (Piranga rubra). The Red-winged Blackbird (Agelaius phoeniceus)...
Authors
Terry J. Spengler, P.L. Leberg, Wylie C. Barrow

Effect of increased water depth on growth of a common perennial freshwater-intermediate marsh species in Coastal Louisiana Effect of increased water depth on growth of a common perennial freshwater-intermediate marsh species in Coastal Louisiana

The response of Sagittaria lancifolia to increased water depths of 7.5 and 15 cm was examined in this field study. Water-depth treatments were achieved by digging sods containing one or two individual plants or ramets of S. lancifolia from the marsh, removing sediment from the resulting hole, and replacing the sods in their original location at the appropriate lower elevation. Plants...
Authors
Rebecca J. Howard, Irving A. Mendelssohn

Species-specific patterns of hyperostosis in marine teleost fishes Species-specific patterns of hyperostosis in marine teleost fishes

The occurrence of swollen or hyperostotic bones in skeletal preparations, preserved museum material or whole fresh specimens of marine teleost fishes was identified in 92 species belonging to 22 families. Patterns of hyperostotic skeletal growth were typically consistent and often species-specific in all individuals larger than a certain size. The taxonomic distribution of hyperostosis...
Authors
William F. Smith-Vaniz, L.S. Kaufman, J. Glowacki

Survey for blood parasites in redheads (Aythya americana) wintering at the Chandeleur Islands, Louisiana Survey for blood parasites in redheads (Aythya americana) wintering at the Chandeleur Islands, Louisiana

We detected no infections with species of Plasmodium, Haemoproteus, Leucocytozoon, Sarcocystis or Trypanosoma in blood smears, liver and spleen impressions, and muscle tissue from 136 redheads (Aythya americana) collected or captured at the Chandeleur Islands, Louisiana (USA), during three winters (1987 to 1990). One bird, a juvenile male, was infected with an unidentified species of...
Authors
Thomas C. Michot, Mary C. Garvin, Earl H. Weidner

Seagrass distribution in the Northern Gulf of Mexico Seagrass distribution in the Northern Gulf of Mexico

Seagrass ecosystems are widely recognized as some of the most productive benthic habitats in estuarine and nearshore waters of the gulf coast. Seagrass meadows provide food for wintering waterfowl and important spawning and foraging habitat for several species of commercially important finfish and shellfish. Physical structure provided by seagrasses affords juveniles refuge from...
Authors
Lawrence R. Handley

An alternative bacteriological medium for the isolation of Aeromonas spp. An alternative bacteriological medium for the isolation of Aeromonas spp.

Two solid bacteriologic media were compared for cultivating Aeromonas spp. from piscine sources: the Rimler-Shotts (RS) medium and a starch-glutamate-ampicillin-penicillin-based medium (SGAP-10C) used for the recovery of Aeromonas spp. from water samples. The selective and differential capacities of the media were assessed March through October 1992 by recovery rate and phenotype of 99...
Authors
J.A. Jenkins, P.W. Taylor

The effects of vertebrate herbivory on plant community structure in the coastal marshes of the Pearl River, Louisiana, USA The effects of vertebrate herbivory on plant community structure in the coastal marshes of the Pearl River, Louisiana, USA

In this study, we investigated the impacts of herbivory by the introduced aquatic herbivore, nutria (Myocastor coypus), on three marsh communities of the Pearl River using fenced exclosures and control plots. Although total community above-ground biomass was reduced by 30% in the plots exposed to herbivory as compared to those protected from herbivory, we found species richness to be...
Authors
K.L. Taylor, J.B. Grace

Integration of manatee life-history data and population modeling Integration of manatee life-history data and population modeling

Aerial counts and the number of deaths have been a major focus of attention in attempts to understand the population status of the Florida manatee (Trichechus manatus latirostris). Uncertainties associated with these data have made interpretation difficult. However, knowledge of manatee life-history attributes increased and now permits the development of a population model. We describe a
Authors
L.L. Eberhardt, Thomas J. O'Shea

Determination of selection gradients using multiple regression versus Structural Equation Modeling (SEM) Determination of selection gradients using multiple regression versus Structural Equation Modeling (SEM)

Selection studies involving multiple intercorrelated independent variables have employed multiple regression analysis as a means to estimate and partition natural and sexual selection's direct and indirect effects. These statistical models assume that independent variables are measured without error. Most would conclude that such is not the case in the field studies for which these...
Authors
B.H. Pugesek, A. Tomer

A highly conserved N-terminal sequence for teleost vitellogenin with potential value to the biochemistry, molecular biology and pathology of vitellogenesis A highly conserved N-terminal sequence for teleost vitellogenin with potential value to the biochemistry, molecular biology and pathology of vitellogenesis

N-terminal amino acid sequences for vitellogenin (Vtg) from six species of teleost fish (striped bass, mummichog, pinfish, brown bullhead, medaka, yellow perch and the sturgeon) are compared with published N-terminal Vtg sequences for the lamprey, clawed frog and domestic chicken. Striped bass and mummichog had 100% identical amino acids between positions 7 and 21, while pinfish, brown...
Authors
L.D. Folmar, N. D. Denslow, R.A. Wallace, G. LaFleur, T. S. Gross, S. Bonomelli, C.V. Sullivan
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