46 research outputs found

    Marine Biodiversity in the Caribbean: Regional Estimates and Distribution Patterns

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    This paper provides an analysis of the distribution patterns of marine biodiversity and summarizes the major activities of the Census of Marine Life program in the Caribbean region. The coastal Caribbean region is a large marine ecosystem (LME) characterized by coral reefs, mangroves, and seagrasses, but including other environments, such as sandy beaches and rocky shores. These tropical ecosystems incorporate a high diversity of associated flora and fauna, and the nations that border the Caribbean collectively encompass a major global marine biodiversity hot spot. We analyze the state of knowledge of marine biodiversity based on the geographic distribution of georeferenced species records and regional taxonomic lists. A total of 12,046 marine species are reported in this paper for the Caribbean region. These include representatives from 31 animal phyla, two plant phyla, one group of Chromista, and three groups of Protoctista. Sampling effort has been greatest in shallow, nearshore waters, where there is relatively good coverage of species records; offshore and deep environments have been less studied. Additionally, we found that the currently accepted classification of marine ecoregions of the Caribbean did not apply for the benthic distributions of five relatively well known taxonomic groups. Coastal species richness tends to concentrate along the Antillean arc (Cuba to the southernmost Antilles) and the northern coast of South America (Venezuela – Colombia), while no pattern can be observed in the deep sea with the available data. Several factors make it impossible to determine the extent to which these distribution patterns accurately reflect the true situation for marine biodiversity in general: (1) highly localized concentrations of collecting effort and a lack of collecting in many areas and ecosystems, (2) high variability among collecting methods, (3) limited taxonomic expertise for many groups, and (4) differing levels of activity in the study of different taxa

    Genetic relationships of grizzly bears (Ursus arctos) in the prudhoe bay region of Alaska: Inference from microsatellite DNA, mitochondrial DNA, and field observations

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    Grizzly bears are abundant in the region of the Prudhoe Bay oil fields in northern Alaska. We used field observations and molecular genetic data to identify parent-offspring and sibling relationships among bears in this region. We determined genotypes at 14 microsatellite DNA loci and the cytochrome b gene of mitochondrial DNA (mtDNA) for 36 bears. We identified 17 possible mother-offspring pairs and 8 possible father-offspring pairs. This includes verification of the relationships of 14 mother-offspring pairs identified from field observations. Three additional mother-offspring pairs and all eight father-offspring pairs were determined from genetic and age data. Relatedness coefficients based on numbers of shared alleles between individuals were as expected: approximately 0.50 for parent-offspring and sibling pairs and approximately 0.75 for a father-offspring pair resulting from a father-daughter mating. The level of genetic variation (mean number of alleles per locus = 6.6, mean heterozygosity = 70%) and allele frequencies in grizzly bears in the Prudhoe Bay region are similar to those in other parts of the species' range

    Comments on brazilian Halichondria Fleming (Halichondriidae, Halichondrida, Demospongiae), with the description of four new species from the S\ue3o Sebasti\ue3o Channel and its environs (Tropical Southwestern Atlantic)

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    Over 70 species of Halichondria Fleming, 1828 are known world-wide, but only five from the Brazilian Coast. Brazilian records have their status re-evaluated here, and four new species are described for the SĂŁo SebastiĂŁo Channel area, in the Tropical Southwestern Atlantic, viz. H. cebimarensis sp. n., H. sulfurea sp. n., H. migottea sp. n. and H. tenebrica sp. n

    Shallow-water Aplysina Nardo (Aplysinidae, Verongida, Demospongiae) from the SĂŁo SebastiĂŁo Channel and its environs (Tropical southwestern Atlantic), with the description of a new species and a literature review of other brazilian records of the genus

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    Two species of Aplysina Nardo, 1834 are described in this article, Aplysina caissara sp. n. and A. fulva (Pallas, 1766). Additionally, a possible third species was identified as A. aff. cauliformis. Collections were done in the SĂŁo SebastiĂŁo Channel area as an ongoing effort to assess the poriferan biodiversity of the northern sector of the SĂŁo Paulo State coastline. Specimens were collected by scuba diving, and descriptions of external morphology are based on the observation of populations alive, and on extensive underwater photography. A literature review of other brazilian records of Aplysina was undertaken, and an ammended species list is offered
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