Serological tracers of meiofaunal food webs

Serological methods utilizing taxon-specific antibodies were used to identify trophic connections in a salt marsh of South Carolina (U. S. A.). The incorporation of meiofauna within the benthic invertebrate food web was detected with these methods when microscopial examinations of predator stomachs revealed nothing but amorphous material and detritus. Measurements of soluble prey proteins in both predator guts and surficial sediments provided data to quantify the trophic connections. Difficulties with data interpretation limit the utility of serological methods for quantifying predation in the field.     

Development and application of monoclonal antibodies for the detection of white spot syndrome virus of penaeid shrimp.

Monoclonal antibodies (MAbs) were produced against white spot syndrome virus (WSSV) of penaeid shrimp. The virus isolate used for immunization was obtained from China in 1994 and was passaged in Penaeus vannamei. The 4 hybridomas selected for characterization all produced MAbs that reacted with the 28 kD structural protein by Western blot analysis. The MAbs tested in dot-immunoblot assays were capable of detecting the virus in hemolymph samples collected from moribund shrimp during an experimentally induced WSSV infection. Two of the MAbs were chosen for development of serological detection methods for WSSV. The 2 MAbs detected WSSV infections in fresh tissue impression smears using a fluorescent antibody for final detection. A rapid immunohistochemical method using the MAbs on Davidson's fixed tissue sections identified WSSV-infected cells and tissues in a pattern similar to that seen with digoxigenin-labeled WSSV-specific gene probes. A whole mount assay of pieces of fixed tissue without paraffin embedding and sectioning was also successfully used for detecting the virus. None of the MAbs reacted with hemolymph from specific pathogen-free shrimp or from shrimp infected with infectious hypodermal and hematopoietic necrosis virus, yellow head virus or Taura syndrome virus. In Western blot analysis, the 2 MAbs did not detect any serological differences among WSSV isolates from China, Thailand, India, Texas, South Carolina or Panama. Additionally, the MAbs did not detect a serological difference between WSSV isolated from penaeid shrimp and WSSV isolated from freshwater crayfish.     

Generalized avian dispersal syndrome contributes to Chinese tallow tree (Sapium sebiferum, Euphorbiaceae) invasiveness

Abstract. Plants possessing generalized dispersal syndromes are likely to be more invasive than those relying on specialist dispersal agents. To address this issue on a local and regional scale, avian seed dispersal of the invasive alien Chinese tallow tree (Sapium sebiferum (L.) Roxb.) was assessed in forests and spoil areas of South Carolina and along forest edges in Louisiana during the 1997–99 fruiting seasons. Tallow trees in these floristically distinct habitats had a few common and many casual visitors, and considerable species overlap among habitats was found. However, bird species differed in the importance of dispersing and dropping seeds among habitats. Important dispersal agents common to forests and spoil areas of South Carolina included Northern Flicker, American Robin and Red‐winged Blackbird, whereas Red‐bellied Woodpecker and European Starling were important in the former and latter habitat, respectively. In Louisiana, Red‐bellied Woodpecker, American Robin, Northern Cardinal and Eastern Bluebird dispersed many seeds. Nearly all species foraging on seeds were winter residents. Estimated numbers of seeds dispersed and dropped were higher in spoil areas of South Carolina than in Louisiana because of higher numbers of individuals per visit, higher seed consumption and seed dropping rates, and longer foraging durations. Within South Carolina, more seeds were dispersed and dropped in spoil areas than in forests because of higher numbers of birds per visit. These findings show that among habitats, tallow tree attracts diverse but variable coteries of dispersal agents that are qualitatively similar in seed usage patterns. We suggest that its generalized dispersal syndrome contributes to effective seed dispersal by many bird species throughout its range. Effects of differential avian use among locales may include changes in local bird communities, and differing tallow tree demographics and invasion patterns.     

Scleroblast cultures from the gorgonianLeptogorgia virgulata (Lamarck) (Coelenterata: Gorgonacea)

Summary Scleroblasts were separated from fragmented tissue of growing tips ofLeptogorgia virgulata and cultured using a modification of the technique of Rannou. Replacement of fetal bovine serum with horse serum seemed to increase scleroblast viability. Cell adhesion occurred from 14 to 43 d. Cultured scleroblasts demonstrated cell aggregation, spicule formation, and extrusion of spicules into the external medium. Cells showing spicules in the process of being extruded appeared on the average after 24 d of culture. Variability among cultures was marked with respect to both division and spicule formation. Healthy cultures were maintained for more than 4 mo. This work was supported by National Science Foundation grants PCM8201389 and DCB8502698. This is contribution No. 674 of Belle W. Baruch Institute for Marine Biology and Coastal Research, University of South Carolina.     

Spatial analysis of Protected Areas of the coastal/marine environment of Brazil

This study analyses the spatial distribution pattern of the Protected Areas (PA) of the Brazilian coastal and marine environments using Ripley's function. The PA are classified in accordance with the three Large Marine Ecosystems (LME) of the Brazilian coast, also incorporating the divisions provided in the National Coastal Management Plan. The similarity among management strategies in the three LME was analysed by the Morisita-Horn index. The assumptions are as follows: (i) the PA will be aggregated in the coastal environment for the three LME and (ii) differences exist with regard to the similarities within and between the LME. The analysed PA showed an aggregate pattern for shorter distances and a uniform pattern for longer distances. These patterns were significant for the East Coast and the South Platform. The management similarity was greater between the East Coast and the South Platform, suggesting that these two LME use similar strategies to manage natural resources. The coastal environment is more protected than the marine environment. Results indicate that the marine environment has a small number of protected environments. Both environments use more frequently the management model of Sustainable-Use Protected Area, with the participation of several social players in the management area. The country is still far from reaching the Targets of Aichi and of the Ministry of the Environment.     

Purification of cytoplasmic antigens from the mycelial phase of Candida albicans: Possible advantages of its use in Candida serology

The serology of candidiasis is complicated by the use of poorly defined antigens. Total extracts of the yeast phase have been commonly used as cytoplasmic antigen, without regard to the significant amounts of carbohydrate that may contaminate such preparations. This is particularly true in the case of commercially available antigens that have been used as cytoplasmic antigens but actually are richer in carbohydrate than in protein. Affinity chromatography in concanavalin A — Sepharose provides a simple procedure to separate carbohydrates, mainly mannan, from protein antigens in whole Candida extracts. By using mannan-poor antigens, the specificity of serological reactions can be increased considerably, since both the positive reactions seen in asymptomatic donors and the cross-reactions seen in patients infected with other fungi are due to anti-mannan antibodies. In contrast, both anti-mannan and anti-cytoplasmic antigen antibodies can be detected in patients suspected of systemic candidiasis. On the other hand, absolute specificity may never be achieved for systemic candidiasis. We have found antibodies against cytoplasmic antigen in a patient allergic to C. albicans, in whom the microorganism was isolated from fecal material. It appears that, under favorable conditions, mucosal sensitization may also trigger a systemic reaction directed against both mannan and cytoplasmic antigens.Publication no. 341 from The Department of Basic and Clinical Immunology and Microbiology, Medical University of South Carolina.     

Serological Strains of Tobacco Ringspot Virus Transmitted by Xiphinema americanum

Five serological strains of tobacco ringspot virus isolated from naturally infected tobacco in North Carolina, and a strain isolated from watermelon in the Rio Grande Valley of Texas were transmitted from cucumber to cucumber by mass-screened and handpicked Xiphinerna americanum from North Carolina. The Eucharis mottle strain from Peru was not transmitted, indicating that a specific strain-vector relationship may exist between the geographically isolated strains from North and South America.     

Ultrastructural investigation of spicule formation in the gorgonianLeptogorgia virgulata (Lamarck) (Coelenterata: Gorgonacea)

Summary Ultrastructural examination of original and regenerated branch tips of the gorgonianLeptogorgia virgulata reveals that spicule formation begins with the aggregation of scleroblasts in the mesoglea. Calcite crystal deposition occurs within a Golgi vacuole containing organic matrix. Vacuole size increases while matrix incorporation and subsequent crystal growth continue, filling the vacuole. At approximately this time, the scleroblasts dissociate and wart formation begins. Further spicule growth stretches the cell into a thin envelope. Fusion of vacuole and plasma membrane followed by breach formation during spicule growth, as well as scleroblast atrophy or migration from mature spicules, result in the transition of the spicule from the intracellular to the extracellular environment. The results also reveal aborted spicules and digestive bodies, implying possible relationships among calcification, detoxification, and waste management.Contribution No 436, Belle W. Baruch Institute for Marine Biology and Coastal Research, University of South Carolina, Columbia, South Carolina, 29208, USA     

Convergent evolution of embryonic growth and development in the eastern fence lizard (Sceloporus undulatus)

Theory predicts that cold environments will select for strategies that enhance the growth of ectotherms, such as early emergence from nests and more efficient use of resources. We used a common garden experiment to detect parallel clines in rates of embryonic growth and development by eastern fence lizards (Sceloporus undulatus). Using realistic thermal conditions, we measured growth efficiencies and incubation periods of lizards from five populations representing two distinct clades. In both clades, embryos from cold environments (Indiana, New Jersey, and Virginia) grew more efficiently and hatched earlier than embryos from warm environments (Florida and South Carolina). Because eggs from cold environments were larger than eggs from warm environments, we experimentally miniaturized eggs from one population (Virginia) to determine whether rapid growth and development were caused by a greater maternal investment. Embryos in miniaturized eggs grew as efficiently and incubated for the same duration as embryos in unmanipulated eggs. Taken together, our results suggest countergradient variation has evolved at least twice in S. undulatus.     

Synthesis and transport of the organic matrix of the spicules in the gorgonian Leptogorgia virgulata (Lamarck) (Coelenterata: Gorgonacea)

Summary The sequence of the synthesis and transport of the organic matrix of spicules has been elucidated in the gorgonian Leptogorgia virgulata by use of ³H-aspartic acid as the tracer in electron-microscopic autoradiography. The entire process of matrix synthesis and transport takes approximately 2 h. It seems that the protein moiety of the organic matrix is synthesized in the RER prior to 5 min following the initial 10 min incubation in the tracer. At the 5 min chase the label is moving from the RER to the Golgi complexes where the carbohydrate moiety of the matrix is presumed to be synthesized. At the 5 to 15 min chases the label is transported out of the Golgi complexes via Golgi vesicles. This phase continues for 30 min. From 60 to 120 min the ³H-aspartic acid moves to the spicules. After 120 min the majority of the label has moved into the spicules. Silver grain counts over both multivesicular and electron-dense bodies remain at relatively low and constant levels over 4 h indicating that neither organelle is involved in the synthesis and transport of the organic matrix.Contribution No 512; Belle W. Baruch Institute for Marine Biology and Coastal Research, University of South Carolina, Columbia, South Carolina 29208, USA     

An autoradiographic study of calcium transport in spicule formation in the gorgonian Leptogorgia virgulata (Lamarck) (Coelenterata: Gorgonacea)

Summary The route of calcium transport to the sites of spicule formation in the gorgonian Leptogorgia virgulata has been examined by the use of ⁴⁵Ca as a tracer in light- and electron-microscopic autoradiography. From 1 to 15 min after the 15-min incubation the tracer accumulates in the axis. After 15 min there is a movement of label out of the axis largely to the peripheral region of the axis, the axial epithelium, and the mesoglea. By 60 min much of the label is in the spicules reaching its maximum level at 120 min. When calcium enters the scleroblast from the mesoglea, it appears to be transported to the spicule by electron-dense bodies. There does not appear to be a simultaneous release of all ionic calcium from the axis, but rather a continuously increasing efflux which levels off at 60–120 min. Not all of the calcium reaching the axis will traverse it en route to spicules; instead, a portion of it apparently precipitates as an amorphous compound.Contribution No. 550; Belle W. Baruch Institute for Marine Biology and Coastal Research, University of South Carolina, Columbia, South Carolina 29208 USA     

Foraminiferal assemblage and reef check census in coral reef health monitoring of East Brazilian margin

Human activity is changing environmental conditions on a global scale. Among the ecosystems that are affected by human activities, coral reefs are among the most prominent. In Brazil, the coral reefs of the Corumbau Marine Extractive Reserve (CMER) and Abrolhos National Marine Park (ANMP) in Bahia state have some of the highest coral cover in the South Atlantic Ocean. Hard coral cover, algal cover, and foraminiferal population distribution patterns were used to assess the coral reef benthic environments, and define a background that can be used in worldwide comparisons in future studies. To compare these two monitoring approaches in different coral reef environments, relative frequency data for occurrence of hard coral and algal cover, using point-intercept transects as proposed by the Reef Check protocol, and foraminiferal samples were collected from Corumbau (nearshore) and Abrolhos (offshore) in April 2005. The foraminiferal assemblage was evaluated using the FORAM index (FI — Foraminifera in Reef Assessment and Monitoring), which provides a numeric diagnosis of suitability of benthic habitat to support calcifying organisms that host algal symbionts, originally developed for Caribbean reef areas. Coral cover in the surveyed areas, both in Corumbau and in Abrolhos, ranged from 13% to 37%, while high foraminiferal diversities (H') were found in all stations. Dominance of symbiont-bearing taxa of Amphistegina lessonii and Archaias angulatus only occurred at two shallow stations, Mato Verde and Siriba, both in Abrolhos, where FI > 4.00. Stations located in Corumbau and Abrolhos had FI values < 4.00. Q-mode cluster analysis showed that foraminifers have specific preferences for physical conditions, especially hydrodynamics and light availability, which influence the FI index. Although coral cover in these areas can be considered good by regional standards, foraminifer analysis showed that the benthic system was unfavorable for symbiont-bearing foraminiferal species at most stations. This discrepancy reveals that the FI must be used with caution in areas other than the northwestern Atlantic and Caribbean where it was developed, and that some coral species can thrive in muddier conditions than can most symbiont-bearing foraminifers.     

Spatial Homogeneity and Temporal Heterogeneity of Red Drum (Sciaenops ocellatus) Microsatellites: Effective Population Sizes and Management Implications

The red drum (Sciaenops ocellatus) is one of a number of species that occupy estuarine waters as juveniles and migrate to open ocean waters as adults. This species has experienced dramatic declines in population numbers over the past 2 decades, which has prompted increasing fishery restriction. In addition, hatchery augmentation has been initiated by several states to increase the abundance of juveniles in local areas. In South Carolina hatchery-reared fish have made significant (20%) contributions to the juvenile population on very local scales. As hatchery-reared fish are typically produced by a small number of individuals, the genetic consequences of augmentation programs are of concern. In this article we assess genetic variation at 5 microsatellite loci in S. ocellatus. The data indicate little geographic differentiation among samples collected along the Atlantic Coast of the United States, but substantial differences among year classes taken from South Carolina. The gene frequency differences among year classes were used to estimate the effective population size (Nc) of S. ocellatus in South Carolina and suggested that Ne was less than 300 from 1990 to 1993 and increased to about 1000 in 1994 and 1995. Whether this increase reflects the effectiveness of management regulations or simply a random fluctuation in S. ocellatus populations is not clear. The data suggest that a limited number of individuals produce the bulk of a given year class and support the sweepstakes hypothesis. Given the small Ne and estimates of the contribution of hatchery-reared fish to the wild stock, it is suggested that programs have the potential to increase, rather than decrease; Ne in the wild.     

Spatial and temporal variation in species-area relationships in the Fynbos biological hotspot

Species-area relations (SARs) are among the few recognized general patterns of ecology, are empirical relations giving the number of species found within an area of a given size and were initially formulated for island environments. The use of SARs has been extended to mainland environments, and to give baseline estimates of extinction rates attending habitat loss. Using current species distributions based on atlas data, we examined the spatial variation of rates of species accumulation and species-area curves for Proteaceae species for all one-minute by one-minute areas within the Cape Floristic Region, South Africa. We compared SARs for current distributions to those generated from modeled future Protea distributions following climate change. Within one biome and for two different scales, there exists a very large spatial variation in turnover rates for current Proteaceae distributions, and we show that these rates will not remain constant as climate warming progresses. As climate changes in coming years, some areas will gain species due to migration, as other areas lose species, and still other areas maintain current rates of species accumulation/turnover. Both current and future distributions show highly variable rates of species accumulation across the landscape. This means that an average species-area relationship will hide a very large interval of variation among SARs, for both current and future Proteaceae distributions. The use of species-area relations to estimate species extinctions following loss of current habitat, or loss of future climatically-suitable area is likely to result in erroneous predictions.     

Coastal and marine wetlands in Gulf St. Vincent,South Australia: understanding their loss and degradation

Despite the vastness of South Australia's coastline, approximately 95% of the state's population of 1.4 million is on the Adelaide metropolitan coast of Gulf St. Vincent. The concentration of human activity around this shallow, sheltered gulf ecosystem has led to conflict and competition over the use of marine and coastal resources. The gulf supports extensive areas of ecologically significant subtidal and tidal coastal wetlands, comprising seagrass meadows, mangroves and saltmarshes, with nine wetlands having recognized national importance. The wetlands support economic activities such as commercial and recreational fishing, tourism and aquaculture, and to a lesser extent, mineral and petroleum exploration and shipping. These environments and activities are threatened by the effects of land-based urbanization, coastal development, stormwater runoff effluent and industrial discharges, and the resultant decline in water quality and food-chain contamination. Marine activities can also have adverse effects (i.e., dredging, sea-dumping, overfishing, fishing methods, oil spills, antifoulants, ballast water introductions), including the developing aquaculture industry. The continued loss and degradation of marine and coastal wetlands in the gulf is exacerbated by inadequate protection measures, lack of integrated management structures and policies, and conflict between competing user groups. Strong policies and integrated decision making based on sound information is required for the equitable and sustainable use of these wetlands. Gulf-level management of multiple-uses would limit the cumulative impacts of human use and coastal development. There is a particular need to protect areas with high conservation value and for future research and marine conservation to focus on the coastal nearshore ecosystem. High priorities are coastal and biodiversity inventories, understanding of ecological processes, linkages between coastal and offshore habitats, and coastal spatial mapping and information systems.     

Distribution of Spiculopteragia pursglovei and S. odocoilei (Nematoda: Trichostrongyloidea) from white-tailed deer (Odocoileus virginianus) in the southeastern United States

The distribution of Spiculopteragia pursglovei (= Apteragia pursglovei) and S. odocoilei (= A. odocoilei) in 12 southeastern states was determined after examining the abomasal contents of 1,369 white-tailed deer over an 8-yr period. Spiculopteragia odocoilei was encountered with much greater frequency than S. pursglovei except in some areas along the Mississippi River drainage and the coasts of North Carolina and South Carolina. In instances where both parasites were found in a population, one usually expressed a dominance in both prevalence and intensity. These findings are in agreement with those of an earlier study conducted in the southeastern United States.     

A Comparison of Hybridization between Mottled Ducks (<Emphasis Type="Italic">Anas fulvigula</Emphasis>)and Mallards (<Emphasis Type="Italic">A. platyrhynchos</Emphasis>) in Florida and South Carolina using Microsatellite DNA Analysis

Interspecific hybridization has been implicated in population declines for some waterfowl species within the mallard complex, and hybridization with mallards (Anas platyrhynchos) is currently considered the largest threat to mottled ducks (A. fulvigula), one North American member of that complex. We assessed genetic variation among 225 mottled ducks and mallards using five microsatellite loci, and detected significant overall differences between these species within two geographic areas. We characterized hybridization in Florida, where mottled ducks are endemic and mallards are beginning to appear on the breeding grounds, and in South Carolina, where mottled ducks were introduced outside their native range. We used Bayesian genetic mixture analysis in an attempt to distinguish between these closely related species. In Florida, we detected two distinct genetic groups, and 10.9% of our samples from Florida mottled ducks were inferred to have been hybrids. In contrast only 3.4% of Florida mallards were inferred to have been hybrids, suggesting asymmetric hybridization. Populations from different geographic areas within Florida exhibited hybridization rates ranging from 0% to 24%. These data indicate a genetic component would be appropriate in actively managing interspecific hybridization in Florida mottled ducks. In contrast, South Carolina mottled ducks and mallards cannot be differentiated.     

Discovery of novel metabolites from marine actinomycetes

Recent findings from culture-dependent and culture-independent methods have demonstrated that indigenous marine actinomycetes exist in the oceans and are widely distributed in different marine ecosystems. There is tremendous diversity and novelty among the marine actinomycetes present in marine environments. Progress has been made to isolate novel actinomycetes from samples collected at different marine environments and habitats. These marine actinomycetes produce different types of new secondary metabolites. Many of these metabolites possess biological activities and have the potential to be developed as therapeutic agents. Marine actinomycetes are a prolific but underexploited source for the discovery of novel secondary metabolites.     

Serological identification of group D streptococci using commercial antisera

Three commercial group D streptococcal antisera were tested for the serological identification of 100 group D enterococci; 20 Streptococcus bovis; 5 isolated from each of the following streptococcal groups: A, B, C and G; and 3 isolates from serological group F. Antisera from Difco Laboratories, BBL, and Wellcome Reagents Limited were used in the classic capillary tube precipitin test on extracts prepared using the Rantz and Randall procedure. No false positive precipitin reactions were observed. Of the enterococcal isolates, all 100 reacted with the Wellcome, 99 reacted with the BBL, and 96 reacted with the Difco group D antisera. However, of the 20 S. bovis isolates, only 2 reacted with the BBL, and 1 reacted with both the Difco and the Wellcome antisera. Each antiserum was then used to prepare staphylococcal coagglutination (CoA) reagents and each isolate was subsequently tested. A simple extraction procedure was performed by suspending colonies of an isolate in a loopful of salin on a microscope slide and gently heating the slide directly in the flame of a Bunsen burner. All 100 enterococci and all 20 S. bovis gave positive results with the BBL and the Wellcome CoA reagents. Using the Difco reagent, 2 S. bovis isolates failed to produce postitive results. No false positive results were observed with the non-Group D isolates. Our results indicate that the CoA technique using commercial group D antisera may provide faster and sometimes more sensitive serological identification than the classic capillary tube precipitin test.