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1.
2.
The recent introduction of the macroalgaUndaria pinnatifida (Harvey) Suringar into the North Atlantic is the latest of a large number of introductions, which have occurred over many years. Some have been deliberate introductions for mariculture or research, while most have been accidental, via vectors such as shipping and shellfish imports. Not all newly recorded species are introductions; some are thought to be merely extensions of distribution, e.g.Laminaria ochroleuca, while others may have been overlooked previously, e.g.Scytosiphon dotyi. Subsequent to its accidental introduction into the waters around the Mediterranean French coast at Sete, most likely with imported oysters,Undaria was deliberately introduced into the North Atlantic, to Brittany, in 1983 by IFREMER for commercial exploitation.Undaria has since spread from the original sites in Brittany, and is now established at several sites on the south coast of England. This paper discusses the introduced brown algae in the North Atlantic and outlines the establishment ofUndaria in the UK.  相似文献   

3.
This work describes a single-locus multiplex PCR assay based on partial COI mitochondrial gene polymorphisms for identification of two Atlantic cryptic species of the sea-bob shrimp, Xiphopenaeus kroyeri (Heller, 1862) that were recently identified using molecular approaches. Reliable identification of cryptic species of Xiphopenaeus spp. has fundamental implications for management and conservation of the sea-bob shrimp fishery stocks. The assay was developed based on sequence polymorphisms of 130 specimens of both species, comprising samples from Venezuela to the southern coast of Brazil, validated by the amplification of 368 adult shrimp samples from nine different locations and confirmed by direct sequencing. The methodology has been optimized to enable the identification of equi-molar mixtures of DNA from up to 10 individuals by PCR reaction, allowing the fast and cheap identification of many specimens for large scale studies on fisheries biology and population genetics. The DNA pooling strategy enabled the identification of a new locality of occurrence of Xiphopenaeus sp. II in the Brazilian coast, Caravelas, indicating that the species distribution may be continuous on the coast, and not disjoint as observed so far.  相似文献   

4.
The South African coastline can be divided into at least four temperature-defined marine bioregions, including the tropical north-east coast, the subtropical east coast, the warm-temperate south coast, and the cool-temperate west coast. There are also two biogeographical transition zones, the south-west coast and the south-east coast (or Wild Coast). The former is sometimes considered a distinct marine bioregion, but no such status has yet been suggested for the Wild Coast. Previous data on the distribution of a recently described but very common coastal crab, Hymenosoma longicrure, indicated that this species could be a Wild Coast endemic. If confirmed, this would be a first indication that this region harbours unique fauna, and that additional research is required to determine whether the Wild Coast constitutes a distinct bioregion that needs to be managed separately from other coastal regions. In the present study, we generated novel genetic data for H. longicrure and compared the species’ range with that of its southern African congeners. We found that H. longicrure occurs north of the Wild Coast, where its range overlaps with that of H. projectum. This finding rejects the idea that the Wild Coast harbours endemic fauna and suggests that the ranges of the two species may be linked to the subtropical and tropical bioregions, respectively, with some southward dispersal facilitated by the southward-flowing Agulhas Current. We conclude that there is as yet no compelling evidence that the Wild Coast is a distinct marine bioregion, and concur with previous biogeographical studies which have suggested that the Wild Coast is an area in which species from the subtropical and warm-temperate bioregions have overlapping ranges. Nonetheless, that fact that no biological information is available for the majority of the region’s estuaries highlights the necessity of comprehensively documenting the biodiversity of this understudied region to fully resolve this issue.  相似文献   

5.
The present study documents three specimens of Benthophiloides brauneri from the River Dniester. It is one of the rarest freshwater fishes in Europe, living along the western coast of the Black and Asov Seas, but these new records are 200 river km from the coast. We discuss whether the species has recently started to establish inland populations or inland specimens have previously been overlooked.  相似文献   

6.
《Biological Control》2001,20(1):76-83
A survey of the phytophagous arthropod fauna associated with sicklepod, Senna obtusifolia, was undertaken between 1991 and 1993 to find biological control agents for this increasingly serious weed in Australia and its closely related congener, Senna tora. The survey concentrated in Mexico on the Gulf coast, the Pacific coast, and the Yucatan peninsula. Additional searching was undertaken in the state of Morelos, Mexico and Honduras. Some 108 phytophagous insect species were found. Literature searches and preliminary observation indicated that 10 species were sufficiently stenophagous to warrant further consideration as potential biocontrol agents. Two species, Mitrapsylla albalineata (Homoptera: Psyllidae) and Conotrachelus sp. ‘Morelos’ (Coleoptera: Curculionidae), have been brought to Australia for further study.  相似文献   

7.
In spite of the utility of DNA barcoding in discriminating marine fish species, few studies using this technique are available along the Brazilian coast, which encompasses nearly 9000 km, distinct biogeographic regions and endemism rates. Therefore, in the present work, we provided the first DNA barcode library based on sequencing of the mitochondrial gene cytochrome c oxidase subunit I (COI) for Actinopterygii fish from northeastern coast of Brazil. The database included 459 specimens from 54 genera, 31 families and 13 orders, with mean interspecific genetic distance of and mean intraspecific distance of 0.15%. As a result, the neighbor-joining (NJ) tree resulted in the molecular identification of 78 taxa. Cryptic species were indicated in Eucinostomus (mojarras) since the 82 specimens morphologically identified as Eucinostomus melanopterus or Eucinostomus sp. formed five clusters with intraspecific genetic distances up to 0.31% and lowest interspecific distance of 11.14%. Eucinostomus jonesii and Eucinostomus harengulus were identified for the first time in ichthyofauna inventories from northeastern Brazil. The present work has also added new records to the Barcode of Life Data System (BOLD), thereby favoring the identification of other specimens at different life stages or in forensic studies. The present dataset reinforces the reliability of DNA barcoding to estimate the overlooked richness of marine fish in Brazilian coast with application in conservation, ecology, systematics and fisheries.  相似文献   

8.
Examination of genetic data (mitochondrial cytochrome c oxidase I) for western Atlantic clingfishes revealed two distinct lineages within a group of individuals originally identified as Acyrtus artius. Subsequent investigation of preserved voucher specimens was conducted to reconcile the genetic data and the existing classification, which is based on morphology. In addition to discovering that one of the genetic lineages is an undescribed species, which we describe as Acyrtus lanthanum, new species, we found that the nominal species Acyrtus artius has a putative venom gland associated with the subopercle that has been overlooked since the species was described nearly 60 years ago. The new species lacks the subopercular gland as does Acyrtus rubiginosus, but one is present in the related Arcos nudus. Venom glands have not been reported previously for the Gobiesocidae, and the venom gland described herein for Acyrtus and Arcos represents the first example in teleost fishes of a venom gland associated with the subopercle.  相似文献   

9.

Background

Over the past 20 years, numerous studies have investigated the ecology and behaviour of malaria vectors and Plasmodium falciparum malaria transmission on the coast of Kenya. Substantial progress has been made to control vector populations and reduce high malaria prevalence and severe disease. The goal of this paper was to examine trends over the past 20 years in Anopheles species composition, density, blood-feeding behaviour, and P. falciparum sporozoite transmission along the coast of Kenya.

Methods

Using data collected from 1990 to 2010, vector density, species composition, blood-feeding patterns, and malaria transmission intensity was examined along the Kenyan coast. Mosquitoes were identified to species, based on morphological characteristics and DNA extracted from Anopheles gambiae for amplification. Using negative binomial generalized estimating equations, mosquito abundance over the period were modelled while adjusting for season. A multiple logistic regression model was used to analyse the sporozoite rates.

Results

Results show that in some areas along the Kenyan coast, Anopheles arabiensis and Anopheles merus have replaced An. gambiae sensu stricto (s.s.) and Anopheles funestus as the major mosquito species. Further, there has been a shift from human to animal feeding for both An. gambiae sensu lato (s.l.) (99% to 16%) and An. funestus (100% to 3%), and P. falciparum sporozoite rates have significantly declined over the last 20 years, with the lowest sporozoite rates being observed in 2007 (0.19%) and 2008 (0.34%). There has been, on average, a significant reduction in the abundance of An. gambiae s.l. over the years (IRR?=?0.94, 95% CI 0.90–0.98), with the density standing at low levels of an average 0.006 mosquitoes/house in the year 2010.

Conclusion

Reductions in the densities of the major malaria vectors and a shift from human to animal feeding have contributed to the decreased burden of malaria along the Kenyan coast. Vector species composition remains heterogeneous but in many areas An. arabiensis has replaced An. gambiae as the major malaria vector. This has important implications for malaria epidemiology and control given that this vector predominately rests and feeds on humans outdoors. Strategies for vector control need to continue focusing on tools for protecting residents inside houses but additionally employ outdoor control tools because these are essential for further reducing the levels of malaria transmission.  相似文献   

10.
The critically endangered leaf-scaled (Aipysurus foliosquamaI) and short-nosed (A. apraefrontalis) sea snakes are currently recognised only from Ashmore and Hibernia reefs ~600km off the northwest Australian coast. Steep population declines in both species were documented over 15 years and neither has been sighted on dedicated surveys of Ashmore and Hibernia since 2001. We examine specimens of these species that were collected from coastal northwest Australian habitats up until 2010 (A.foliosquama) and 2012 (A. apraefrontalis) and were either overlooked or treated as vagrants in conservation assessments. Morphological variation and mitochondrial sequence data confirm the assignment of these coastal specimens to A. foliosquama (Barrow Island, and offshore from Port Hedland) and A.apraefrontalis (Exmouth Gulf, and offshore from Roebourne and Broome). Collection dates, and molecular and morphological variation between coastal and offshore specimens, suggest that the coastal specimens are not vagrants as previously suspected, but instead represent separate breeding populations. The newly recognised populations present another chance for leaf-scaled and short-nosed sea snakes, but coastal habitats in northwest Australia are widely threatened by infrastructure developments and sea snakes are presently omitted from environmental impact assessments for industry. Further studies are urgently needed to assess these species’ remaining distributions, population structure, and extent of occurrence in protected areas.  相似文献   

11.
We compare ‘temperate data’ with information contained in 49 surveys of cryptomonads from Brazilian tropical regions. These surveys contain a total of 351 records relative to a total of 38 taxa at the species level or below. All taxa were identified using traditional morphological characters visible with the light microscope. Two taxa appear to be new species, and amongst the known species Cryptomonas erosa Ehrenberg is the most frequently recorded one. To date two species of Pseudocryptomonas Bicudo & Tell (all containing multiple photosynthetic endosymbionts/chloroplasts) and the species Cryptomonas brasiliensis Castro, C. Bicudo & D. Bicudo have not been found outside Brazil. With respect to their geographical distribution in Brazilian tropical regions, cryptomonads are better represented in reservoirs and coastal lagoons located in the south-eastern part of the country. Some species appear to be restricted to brackish coastal ecosystems (oligo- to mesohaline and meso- to eutrophic waters). There are only four records of marine cryptomonads. A comparative study of three different kinds of shallow aquatic environments in Brazil – north-eastern reservoirs, a flood-plain Amazonian lake, and brackish lagoons on the south-eastern coast – shows that cryptomonads are to be found constantly, and their species number density, and biomass are generally low (usually <10%) in relation to the other phytoplankton. The case of Plagioselmis Butcher emend. Novarino, Lucas & Morrall, amongst others, exemplifies the great difficulties encountered while attempting to interpret biogeographical information based on light microscopy within the context of a modern systematic and taxonomic framework based on electron microscopy.  相似文献   

12.
The marine benthic brown algae of the north coast of Papua New Guinea (mainly from Madang province) are documented, based on collections made by the first author, between 1980 and 1990. All records [34 identified taxa (+Sargassum spp.)] are listed with bibliographic, taxonomic, nomenclatural and biogeographical notes. The specimens belonging to the genus Dictyota are identified according to recent species definitions. D. magneana De Clerck et Coppejans is described as new to science. Only some representatives of the genus Sargassum have been identified to species level. The phaeophycean flora of the north coast is very similar to that of the south coast (Port Moresby area); nevertheless some differences can be observed.  相似文献   

13.
Marine fungi are severely understudied in the polar regions. We used molecularly identified cultures to study fungi inhabiting 50 intertidal and sea-floor logs along the North Norwegian coast. The aim was to explore the taxonomic and ecological diversity and to examine factors shaping the marine wood-inhabiting fungal communities. The 577 pure cultures analyzed clustered into 147 operational taxonomic units (OTUs) based on 97 % ITS sequence similarity. Ascomycota dominated, but OTUs belonging to Basidiomycota, Mucoromycotina and Chytridiomycota were also isolated. Nine OTUs could not be assigned to any fungal phylum. Almost half of the OTUs were considered non-marine. The western and eastern part of the Norwegian Barents Sea coast hosted different communities. Geography, substratum and site level variables contributed to shaping these communities. We characterized a previously overlooked fungal community in a poorly studied area, discovered high diversity and report many taxa for the first time from the marine environment.  相似文献   

14.
Minidiscus species are the smallest centric diatoms of the marine phytoplankton (with diameters ranging from 1.9 to 7.5 μm), and they may be easily overlooked in routine analyses. Three species of the genus occurred in samples collected in the Mexican Pacific Ocean: Minidiscus trioculatus, M. comicus and M. chilensis. The identification of these species represents the first documented records for the Mexican Pacific: Minidiscus trioculatus and M. chilensis off the west coast of Baja California, and M. comicus in the Gulf of Tehuantepec. Minidiscus trioculatus is considered a cosmopolitan species, M. comicus has a wide distribution in subtropical-temperate waters, and M. chilensis may be mainly regarded as a temperate to cold-water form.  相似文献   

15.
The widely distributed long-finned pilot whale (Globicephala melas) has been reported off the Chilean coast, from Iquique (20°12′S) south to Navarino Island (55°15′S; 67°30′W), but little is known about its biology or ecology in the region. Here, we report on the prey of this species, identified by stomach content analyses from animals stranded on Holget Islets, Beagle Channel, southern Chile in August 2006. The stomachs of seven individuals (six females and one male) contained cephalopod remains. The prey composition found in these southern Chilean pilot whales was similar to that described in other parts of the world and the Southern Ocean. This is the first report on the feeding habits of this species from Chile.  相似文献   

16.
The peracarid isopod, Stenosoma nadejda (Rezig 1989), until recently considered to be endemic of the Mediterranean region, was first reported in the Atlantic coast of southern Spain in 2001, and in 2006 abundant populations were discovered throughout the southwestern Portuguese coast. This fast expansion was intriguing because, as a direct brooder, this species has limited mechanisms for dispersal, such as rafting on seaweeds. Did S. nadejda recently extend its range into the Atlantic or was it overlooked in the past? We examined the patterns of genetic diversity and population differentiation accordingly by sequencing the cytochrome c oxidase subunit I mitochondrial gene from 75 individuals collected in five locations in Atlantic Iberia and one in the Mediterranean. Our results indicate that the newly discovered Atlantic populations of S. nadejda appear to be old and have long persisted on Atlantic shores rather than being a recent introduction. High levels of genetic diversity and geographic structure were uncovered in what was initially suspected to be an ‘invasive’ species. Recent changes in population dynamics may have made S. nadejda more conspicuous in the Atlantic shores, or a more comprehensive survey led to the recognition of this species where it was not expected.  相似文献   

17.
Although the diversity of dinoflagellates has been intensively studied in several locations in the Mediterranean Sea since the 1950s, it is only during the last two decades that the morphotype of the toxic unarmoured dinoflagellate Cochlodinium polykrikoides Margalef has been detected, coinciding with its apparent worldwide expansion in marine coastal waters. In this study, vegetative cells of C. polykrikoides morphotype from the Catalan coast (NW Mediterranean Sea) were detected and isolated, and the DNA from collected cells was sequenced. While in the Mediterranean Sea, detections are scarce and C. polykrikoides is consistently present at low concentrations, we reported exceptional blooms of this species, in which the maximum abundance reached 2 × 104 cells L−1. Partial LSU rDNA region sequences showed that most C. polykrikoides populations from the Catalan coast formed a new differentiated ribotype, but others were included within the ‘Philippines’ ribotype, demonstrating their coexistence in the Mediterranean Sea. Thus, the current biogeographic nomenclature of the ribotypes is likely to be invalid with respect to the available information from populations comprising the ‘Philippines’ ribotype. The phylogeny suggests the existence of cryptic species that should be evaluated for species-level status. Accordingly, the ribotype determination must be carefully evaluated for all detections and bloom events, since accurate characterization of the morphology, ecophysiology and distribution of the ribotypes are not well resolved.  相似文献   

18.
19.
Recurrent high-biomass blooms of a gymnodinioid species have been periodically recorded at different sites in the NW Mediterranean Sea (Catalan and Sardinian coast), causing intense discolorations of the water. In this study, several strains of the causative organism were isolated and subsequently studied with respect to the morphology of the vegetative cells and different life cycle stages, pigments profile, and molecular phylogeny. Based on phylogenetic analyses, the strains were placed within the Gymnodinium sensu stricto clade. The species possessed a horseshoe-shaped apical groove running anticlockwise around the apex and the major accessory pigment was identified as peridinin. These characteristics place the organism within the Gymnodinium genus, as defined today, although some other characteristics, such as vesicular chambers in the nuclear envelope and a nuclear fibrous connective were not observed. Morphologically, the isolates highly resemble Gyrodinium vorax (Biecheler) but major differences with the latter suggest that they comprise a new species, Gymnodinium litoralis sp. nov. The resting cyst of this species is described herein from field samples of the Catalan and Sardinian coast; pellicle cysts were observed in field samples and also in cultures. This species recurrently produces high biomass blooms (>106 cell L−1) in summer along several beaches and coastal lagoons in the NW Mediterranean Sea (L’Estartit, La Muga River mouth, and Corru S’Ittiri). Knowledge about its geographic distribution is limited, since the precise identification of G. litoralis from the field or fixed samples can be difficult. Therefore we expect that molecular studies will reveal a much wider distribution of the species.  相似文献   

20.
Gary L. Smith 《Brittonia》1977,29(4):368-375
The new combination,Atrichum cylindricum (Willd. ex Weber) G. Smith is made for a moss described in 1741 by Dillenius, based on a Clayton specimen from Virginia. This species, which has been overlooked by American bryologists, is now known from the southern Atlantic and Gulf coastal plain, and the Cumberland Plateau in eastern Tennessee.Atrichum undulatum var.attenuatum Bruch & Schimp. is a synonym. Illustrations of the species and a map of its distribution are included.  相似文献   

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