877 research outputs found

    A checklist of the marine Harpacticoida (Copepoda) of the Caribbean Sea

    Get PDF
    Recent surveys on the benthic harpacticoids in the northwestern sector of the Caribbean have called attention to the lack of a list of species of this diverse group in this large tropical basin. A first checklist of the Caribbean harpacticoid copepods is provided herein; it is based on records in the literature and on our own data. Records from the adjacent Bahamas zone were also included. This complete list includes 178 species; the species recorded in the Caribbean and the Bahamas belong to 33 families and 94 genera. Overall, the most species family was the Miraciidae (27 species),followed by the Laophontidae (21), Tisbidae (17), and Ameiridae (13). Up to 15 harpacticoid families were represented by one or two species only. Excluding the Bahamian records, the number of species recorded herein for the Caribbean Basin is 139. The distribution of the species richness within the Caribbean Basin is asymmetrical; the northwestern sector (Mexican Caribbean) is the most species, it concentrates up to 45% of the species recorded in the Caribbean. The insular Caribbean is nearly as diverse as the continental areas (75 vs 83 species recorded, respectively). The dominance of taxa related to coastal systems with coarse and fine sands and carbonatesediments reveals the general trend in the type of habitats surveyed in the Caribbean Sea. Up to 37 species found in the Mexican Caribbean represent new records for this country. There are enormous hiatuses in the knowledge of the Caribbean harpacticoids in terms of geographic, bathymetric, and environmental coverage. It is expected this list will grow rapidly and many undescribed forms will be discovered when understudied or unexplored environments are surveyed in detail

    The South American Neritic Copepod Ctenocalanus heronae Vega-Pérez and Bowman (Calanoida) in the Gulf of Mexico, with Comments on the Taxonomy of the Genus

    Get PDF
    A single adult female specimen of the calanoid copepod Ctenocalanus heronaeVega-Pérez and Bowman was collected during a zooplankton survey carried out in February 1997 in Campeche Sound, the central-southeastern portion of the Gulf of Mexico. The taxonomy of the genus Ctenocalanus Giesbrecht is still unclear. Characters used to separate the species have been considered rather subtle. In this paper the taxonomic illustrations of the specimen collected are accompanied by a revision of the taxonomic features commonly used to identify the species. New, previously overlooked characters such as the cephalosome/urosome ratio, the shape of the 5th legs and particularly the structure of legs 1 and 2, are presented and might turn out to be useful to separate some of the species. This record of C. heronae in the Gulf of Mexico also represents the first reported occurrence of the genus in the Northwestern Tropical Atlantic and increases remarkably the known distribution of the species from the 24°S to the 18°N

    A Survey of the Reef-Related Medusa (Cnidaria) Community in the Western Caribbean Sea

    Get PDF
    The species composition, distribution, and abundance of medusae collected during a 4-day plankton survey in a reef system of the Mexican Caribbean were studied. Highest mean medusae abundance was observed over the fore-reef zone and in daytime samples. Lowest abundances occurred in the reef lagoon and at dusk. Seventeen species were identified, with Liriope tetraphylla, Aglaura hemistoma, Cubaia aphrodite, and Sarsia prolifera being the most abundant. They belong to a group of medusae dominant along the world\u27s second largest barrier reef. Cluster analysis revealed primary (fore-reef) and secondary (reef lagoon, channel) oceanic groups, showing the strong oceanic influence along and across the reef system. Day-to-day variation in the reef medusan community seemed relatively unimportant. The community structure of the reef medusa fauna appeared to be quite uniform despite the expected migratory behavior of these predators, tidal exchange across the reef, introduction of oceanic species, and time of day. The species composition was most closely related to that of the Campeche Bank and oceanic Caribbean waters. Dominance of oceanic medusae within the reef lagoon was attributed to the narrowness of the continental shelf and the mesoscale hydrological features of the zone

    A Survey of the Reef-Related Medusa (Cnidaria) Community in the Western Caribbean Sea

    Get PDF
    The species composition, distribution, and abundance of medusae collected during a 4-day plankton survey in a reef system of the Mexican Caribbean were studied. Highest mean medusae abundance was observed over the fore-reef zone and in daytime samples. Lowest abundances occurred in the reef lagoon and at dusk. Seventeen species were identified, with Liriope tetraphylla, Aglaura hemistoma, Cubaia aphrodite, and Sarsia prolifera being the most abundant. They belong to a group of medusae dominant along the world\u27s second largest barrier reef. Cluster analysis revealed primary (fore-reef) and secondary (reef lagoon, channel) oceanic groups, showing the strong oceanic influence along and across the reef system. Day-to-day variation in the reef medusan community seemed relatively unimportant. The community structure of the reef medusa fauna appeared to be quite uniform despite the expected migratory behavior of these predators, tidal exchange across the reef, introduction of oceanic species, and time of day. The species composition was most closely related to that of the Campeche Bank and oceanic Caribbean waters. Dominance of oceanic medusae within the reef lagoon was attributed to the narrowness of the continental shelf and the mesoscale hydrological features of the zone

    An Illustrated Record and Range Extension of Caligus chelifer (Copepoda, Siphonostomatoida) in the Gulf of Mexico

    Get PDF
    A male specimen of the copepod Caligus chelifer Wilson, 1905, was collected during a plankton survey carried out during February 1994 off the Mexican coasts of the eastern Gulf of Mexico (Tamaulipas state). This is the first record of this species in Mexican waters and south of the 25ºN in the Northwestern Atlantic. Taxonomic illustrations of the specimen are provided

    The pathogenesis of low pathogenicity H7 avian influenza viruses in chickens, ducks and turkeys

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Avian influenza (AI) viruses infect numerous avian species, and low pathogenicity (LP) AI viruses of the H7 subtype are typically reported to produce mild or subclinical infections in both wild aquatic birds and domestic poultry. However relatively little work has been done to compare LPAI viruses from different avian species for their ability to cause disease in domestic poultry under the same conditions. In this study twelve H7 LPAI virus isolates from North America were each evaluated for their comparative pathogenesis in chickens, ducks, and turkeys.</p> <p>Results</p> <p>All 12 isolates were able to infect all three species at a dose of 10<sup>6 </sup>50% egg infectious doses based on seroconversion, although not all animals seroconverted with each isolate-species combination. The severity of disease varied among isolate and species combinations, but there was a consistent trend for clinical disease to be most severe in turkeys where all 12 isolates induced disease, and mortality was observed in turkeys exposed to 9 of the 12 viruses. Turkeys also shed virus by the oral and cloacal routes at significantly higher titers than either ducks or chickens at numerous time points. Only 3 isolates induced observable clinical disease in ducks and only 6 isolates induced disease in chickens, which was generally very mild and did not result in mortality. Full genome sequence was completed for all 12 isolates and some isolates did have features consistent with adaptation to poultry (e.g. NA stalk deletions), however none of these features correlated with disease severity.</p> <p>Conclusions</p> <p>The data suggests that turkeys may be more susceptible to clinical disease from the H7 LPAI viruses included in this study than either chickens or ducks. However the severity of disease and degree of virus shed was not clearly correlated with any isolate or group of isolates, but relied on specific species and isolate combinations.</p

    Socio-occupational status and congenital anomalies

    Get PDF
    Background: The aim of this study is to investigate the association between socio-occupational status and the frequency of major congenital anomalies in offspring. Methods: The study population comprised 81 435 live singletons born to mothers enrolled in the Danish National Birth Cohort between 1996 and 2002. A total of 3352 cases of major congenital anomalies (EUROCAT criteria) were identified by linkage to the National Hospital Discharge Register. Malformations were recorded at birth or in the first year of life. Information about maternal and paternal socio-occupational status was collected prospectively using telephone interviews in the second trimester of pregnancy and was categorized as high, middle or low. Associations were measured as relative prevalence ratios using the highest socio-occupational status within the couple as the reference group. Results: The prevalence of all recorded major congenital anomalies was similar, about 4%, in all the socio-occupational categories. Low social status of the couple did, however, correlate with a higher prevalence of congenital anomalies of the ‘respiratory system’. No association was substantially attenuated when we adjusted for maternal and paternal age, smoking status, maternal alcohol habits, folic acid intake and body mass index. When malformations of the heart and the cardiovascular system were grouped together, they were more frequent in families where both parents presented a low socio-occupational status. Conclusion: We detected an association between low socio-occupational status and congenital anomalies of the respiratory system, the heart and the circulatory system. These malformations are good candidates for a large study on occupational, environmental and social determinants
    • …
    corecore