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1.
Increasing skeletal evidence from the U.S.A., Mexico, Colombia, and Brazil strongly suggests that the first settlers in the Americas had a cranial morphology distinct from that displayed by most late and modern Native Americans. The Paleoamerican morphological pattern is more generalized and can be seen today among Africans, Australians, and Melanesians. Here, we present the results of a comparative morphological assessment of a late Paleoindian/early archaic specimen from Capelinha Burial II, southern Brazil. The Capelinha skull was compared with samples of four Paleoindian groups from South and Central America and worldwide modern groups from W.W. Howells' studies. In both analyses performed (classical morphometrics and geometric morphometrics), the results show a clear association between Capelinha Burial II and the Paleoindians, as well as Australians, Melanesians, and Africans, confirming its Paleoamerican status.  相似文献   

2.
Oysters (Ostreidae) manifest a high degree of phenotypic plasticity, whereby morphology is of limited value for species identification and taxonomy. By using molecular data, the aim was to genetically characterize the species of Crassostrea occurring along the Brazilian coast, and phylogenetically relate these to other Crassostrea from different parts of the world. Sequencing of the partial cytochrome oxidase c subunit I gene (COI), revealed a total of three species of Crassostrea at 16 locations along the Brazilian coast. C. gasar was found from Curuçá (Pará state) to Santos (São Paulo state), and C. rhizophorae from Fortim (Ceará state) to Florianópolis (Santa Catarina state), although small individuals of the latter species were also found at Ajuruteua beach (municipality of Bragança, Pará state). An unidentified Crassostrea species was found only on Canela Island, Bragança. Crassostrea gasar and C. rhizophorae grouped with C. virginica, thereby forming a monophyletic Atlantic group, whereas Crassostrea sp. from Canela Island was shown to be more similar to Indo-Pacific oysters, and either arrived in the Atlantic Ocean before the convergence of the Isthmus of Panama or was accidentally brought to Brazil by ship.  相似文献   

3.
In Oman, the presence of highly productive marine environments, coupled with relatively limited land resources, have led to intense exploitation of coastal resources, but the question of the seasonality of occupation of coastal sites remains open. Our aim is to evaluate the contribution of marine resources to the diet of the Neolithic population of Ra's al‐Hamra 5 (RH‐5) to shed new light on its mobility, using stable isotopes and radiocarbon (14C) dating as dietary tracers. Charcoal, shell, human bone and enamel apatite from eight contemporary graves were sampled. Graves are thought to provide the best chance to obtain marine and terrestrial remains that were contemporary with the human remains in order to calculate the marine reservoir effect (MRE) for this period. Inter‐individual variation in human bone apatite δ13C value is small, suggesting a homogenous diet. Bone apatite 14C ages are very close to the shell ages while enamel is significantly younger and plots near the charcoal ages. Older enamel ages were obtained when a stronger acetic treatment was used, demonstrating that the young ages are due to diagenetic alteration rather than a diachronic change in diet and that only bone apatite retained in vivo dietary signals. Bone ages indicate a heavy reliance on marine resources and it is therefore unlikely that the individuals analyzed here were leaving the coast seasonally, although mobility along the coast cannot be excluded. Am J Phys Anthropol 153:353–364, 2014. © 2013 Wiley Periodicals, Inc.  相似文献   

4.
Human activities in coastal areas are accelerating ecosystem changes at an unprecedented pace, resulting in habitat loss, hydrological modifications, and predatory species declines. Understanding how these changes potentially cascade across marine and freshwater ecosystems requires knowing how mobile euryhaline species link these seemingly disparate systems. As upper trophic level predators, bull sharks (Carcharhinus leucas) play a crucial role in marine and freshwater ecosystem health. Telemetry studies in Mobile Bay, Alabama, suggest that bull sharks extensively use the northern portions of the bay, an estuarine–freshwater interface known as the Mobile‐Tensaw Delta. To assess whether bull sharks use freshwater habitats in this region, environmental DNA surveys were conducted during the dry summer and wet winter seasons in 2018. In each season, 5 × 1 L water samples were collected at each of 21 sites: five sites in Mobile Bay, six sites in the Mobile‐Tensaw Delta, and ten sites throughout the Mobile‐Tombigbee and Tensaw‐Alabama Rivers. Water samples were vacuum‐filtered, DNA extractions were performed on the particulate, and DNA extracts were analyzed with Droplet Digital™ Polymerase Chain Reaction using species‐specific primers and an internal probe to amplify a 237‐base pair fragment of the mitochondrial NADH dehydrogenase subunit 2 gene in bull sharks. One water sample collected during the summer in the Alabama River met the criteria for a positive detection, thereby confirming the presence of bull shark DNA. While preliminary, this finding suggests that bull sharks use less‐urbanized, riverine habitats up to 120 km upriver during Alabama''s dry summer season.  相似文献   

5.
The mummification methods of an ancient maritime population on the northern coast of Chile are reviewed and the findings in an additional seven individuals are reported. Members of this cultural group, Chinchorro, practiced a selective, elaborate form of artificial mummification which persisted more than 4,000 years. Its complexity diminished with time, gradually disappearing after 2,000 B. C. One of the seven individuals herein reported is a rather poorly but spontaneously (“naturally”) preserved body that may represent the oldest mummy reported to date–about 9,000 years old. Chemical reconstruction of their diet demonstrates that the principal component was derived from marine resources with only minor supplementation from terrestrial hunting as well as food gathering from river mouth vegetal sources, confirming the marine dependence of their adaptational strategy. © 1993 Wiley-Liss, Inc.  相似文献   

6.
Recent collections of tetrasporangiate “Heterosiphonia” japonica Yendo from Watch Hill to Point Judith, Rhode Island, represent the first report of this nonnative alga in the western Atlantic. Native to the Pacific Ocean, this species was unintentionally introduced into European waters by 1984 and has subsequently invaded the eastern Atlantic Ocean widely from France to Norway and south into the Mediterranean Sea. Thus far, all western Atlantic collections of this species are confined to the outer coast of Rhode Island, and at present are not found in Narragansett Bay or in Long Island Sound along the Connecticut coast. Molecular and morphological studies confirm the identity of this newly introduced invasive species.  相似文献   

7.

Background

New marine invasions have been recorded in increasing numbers along the world''s coasts due in part to the warming of the oceans and the ability of many invasive marine species to tolerate a broader thermal range than native species. Several marine invertebrate species have invaded the U.S. southern and mid-Atlantic coast from the Caribbean and this poleward range expansion has been termed ‘Caribbean Creep’. While models have predicted the continued decline of global biodiversity over the next 100 years due to global climate change, few studies have examined the episodic impacts of prolonged cold events that could impact species range expansions.

Methodology/Principal Findings

A pronounced cold spell occurred in January 2010 in the U.S. southern and mid-Atlantic coast and resulted in the mortality of several terrestrial and marine species. To experimentally test whether cold-water temperatures may have caused the disappearance of one species of the ‘Caribbean Creep’ we exposed the non-native crab Petrolisthes armatus to different thermal treatments that mimicked abnormal and severe winter temperatures. Our findings indicate that Petrolisthes armatus cannot tolerate prolonged and extreme cold temperatures (4–6°C) and suggest that aperiodic cold winters may be a critical ‘reset’ mechanism that will limit the range expansion of other ‘Caribbean Creep’ species.

Conclusions/Significance

We suggest that temperature ‘aberrations’ such as ‘cold snaps’ are an important and overlooked part of climate change. These climate fluctuations should be accounted for in future studies and models, particularly with reference to introduced subtropical and tropical species and predictions of both rates of invasion and rates of unidirectional geographic expansion.  相似文献   

8.
Most of the world''s living marine resources inhabit coastal environments, where average thermal conditions change predictably with latitude. These coastal latitudinal temperature gradients (CLTG) coincide with important ecological clines,e.g., in marine species diversity or adaptive genetic variations, but how tightly thermal and ecological gradients are linked remains unclear. A first step is to consistently characterize the world''s CLTGs. We extracted coastal cells from a global 1°×1° dataset of weekly sea surface temperatures (SST, 1982–2012) to quantify spatial and temporal variability of the world''s 11 major CLTGs. Gradient strength, i.e., the slope of the linear mean-SST/latitude relationship, varied 3-fold between the steepest (North-American Atlantic and Asian Pacific gradients: −0.91°C and −0.68°C lat−1, respectively) and weakest CLTGs (African Indian Ocean and the South- and North-American Pacific gradients: −0.28, −0.29, −0.32°C lat−1, respectively). Analyzing CLTG strength by year revealed that seven gradients have weakened by 3–10% over the past three decades due to increased warming at high compared to low latitudes. Almost the entire South-American Pacific gradient (6–47°S), however, has considerably cooled over the study period (−0.3 to −1.7°C, 31 years), and the substantial weakening of the North-American Atlantic gradient (−10%) was due to warming at high latitudes (42–60°N, +0.8 to +1.6°C,31 years) and significant mid-latitude cooling (Florida to Cape Hatteras 26–35°N, −0.5 to −2.2°C, 31 years). Average SST trends rarely resulted from uniform shifts throughout the year; instead individual seasonal warming or cooling patterns elicited the observed changes in annual means. This is consistent with our finding of increased seasonality (i.e., summer-winter SST amplitude) in three quarters of all coastal cells (331 of 433). Our study highlights the regionally variable footprint of global climate change, while emphasizing ecological implications of changing CLTGs, which are likely driving observed spatial and temporal clines in coastal marine life.  相似文献   

9.
Located on the Iberian Mediterranean coast, El Collado is an open-air site where a rescue excavation was conducted over two seasons in 1987 and 1988. The archaeological work excavated a surface area of 143m2 where 14 burials were discovered, providing skeletal remains from 15 individuals. We have obtained AMS dates for 10 of the 15 individuals by means of the direct dating of human bones. The ranges of the probability distribution of the calibrated dates suggest that the cemetery was used during a long period of time (781–1020 years at a probability of 95.4%). The new dates consequently set back the chrono-cultural attribution of the cemetery from the initial proposal of Late Mesolithic to an older date in the Early Mesolithic. Therefore, El Collado becomes the oldest known cemetery in the Iberian Peninsula, earlier than the numerous Mesolithic funerary contexts documented on the Atlantic façade such as the Portuguese shell-middens in the Muge and Sado Estuaries or the funerary sites on the northern Iberian coast.  相似文献   

10.
The public authorities have recently approved the building of a Littoral Station in Aguda, a small fishing village on the Atlantic coast, 15 km south of the River Douro estuary in the municipal area of Vila Nova de Gaia. The internal structure of the building involves a Fishery Museum exhibiting ancient and modern gear, a Public Aquarium displaying the local marine fauna and flora and a Research and Educational Department for marine biology, aquaculture and fishery. The project was drawn up by the architect João Paulo Peixoto, in collaboration with local engineers, and the author. In Aguda there is an active, small-scale fishery, based on traditional methods handed down from generation to generation. The almost unstudied local marine fauna and flora is characterized by a high diversity of invertebrates and a rich abundance of fish stocks. Easy access to a variety of marine biotopes is guaranteed by means of the local fishing-fleet, thus supporting the Station's programme of education and research.  相似文献   

11.
The diet of the Kelp Gull (Larus dominicanus) was investigated at the northern limit of its distribution along the South American Atlantic coast. We used two complementary methods, pellet analysis and stable isotope analysis (SIA), to describe and compare Kelp Gull feeding ecology in freshwater and marine environments. The assimilated diet over two different time scales was investigated via SIA of plasma and red blood cells, blood components with different turnover rates. Fish composed the bulk of the diet of Kelp Gulls in both marine (White Croaker Micropogonias furnieri and Banded Croaker Paralonchurus brasiliensis) and limnetic areas (Armoured Catfish Loricariidae and La Plata Croaker Pachyurus bonariensis), despite the importance of benthic prey from the intertidal zone in samples collected from the marine environment (Wedge Clam Donax hanleyanus and the Yellow Clam Mesodesma mactroides). The fish consumed by the gulls were common discards from fisheries in both environments, and marine bivalves were found at a high density at the marine beach. Diet varied between the different time scales analysed. Conventional diet data generally agreed with stable isotope model estimates, emphasising the importance of using complementary approaches in dietary studies.  相似文献   

12.
Here we report on a stable isotope palaeodietary study of a Imperial Roman population interred near the port of Velia in Southern Italy during the 1st and 2nd centuries AD. Carbon and nitrogen stable isotope analyses were performed on collagen extracted from 117 adult humans as well as a range of fauna to reconstruct individual dietary histories. For the majority of individuals, we found that stable isotope data were consistent with a diet high in cereals, with relatively modest contributions of meat and only minor contributions of marine fish. However, substantial isotopic variation was found within the population, indicating that diets were not uniform. We suggest that a number of individuals, mainly but not exclusively males, had greater access to marine resources, especially high trophic level fish. However, the observed dietary variation did not correlate with burial type, number of grave goods, nor age at death. Also, individuals buried at the necropolis at Velia ate much less fish overall compared with the contemporaneous population from the necropolis of Portus at Isola Sacra, located on the coast close to Rome. Marine and riverine transport and commerce dominated the economy of Portus, and its people were in a position to supplement their own stocks of fish with imported goods in transit to Rome, whereas at Velia marine exploitation existed side‐by‐side with land‐based economic activities. Am J Phys Anthropol, 2009. © 2009 Wiley‐Liss, Inc.  相似文献   

13.

Background

Age-related macular degeneration (AMD) is associated with lipofuscin accumulation whereas the content of melanosomes decreases. Melanosomes are the main storage of zinc in the pigmented tissues. Since the elderly population, as the most affected group for AMD, is prone to zinc deficit, we investigated the chemical and ultrastructural effects of zinc deficiency in pigmented rat eyes after a six-month zinc penury diet.

Methodology/Principal Findings

Adult Long Evans (LE) rats were investigated. The control animals were fed with a normal alimentation whereas the zinc-deficiency rats (ZD-LE) were fed with a zinc deficient diet for six months. Quantitative Energy Dispersive X-ray (EDX) microanalysis yielded the zinc mole fractions of melanosomes in the retinal pigment epithelium (RPE). The lateral resolution of the analysis was 100 nm. The zinc mole fractions of melanosomes were significantly smaller in the RPE of ZD-LE rats as compared to the LE control rats. Light, fluorescence and electron microscopy, as well as immunohistochemistry were performed. The numbers of lipofuscin granules in the RPE and of infiltrated cells (Ø>3 µm) found in the choroid were quantified. The number of lipofuscin granules significantly increased in ZD-LE as compared to control rats. Infiltrated cells bigger than 3 µm were only detected in the choroid of ZD-LE animals. Moreover, the thickness of the Bruch''s membrane of ZD-LE rats varied between 0.4–3 µm and thin, rangy ED1 positive macrophages were found attached at these sites of Bruch''s membrane or even inside it.

Conclusions/Significance

In pigmented rats, zinc deficiency yielded an accumulation of lipofuscin in the RPE and of large pigmented macrophages in the choroids as well as the appearance of thin, rangy macrophages at Bruch''s membrane. Moreover, we showed that a zinc diet reduced the zinc mole fraction of melanosomes in the RPE and modulated the thickness of the Bruch''s membrane.  相似文献   

14.
Two allopatric morphotypes of the genus Rinelocaria were compared through the allozyme electrophoresis technique: one morphotype, R. pentamaculata, from the Keller River in the middle stretch of the Ivaí River basin and the other, R. aff. pentamaculata, from the São João River in the upper portion of the Ivaí River basin. The morphotype from the São João River was collected upstream from the São João waterfall, which is about 80 m deep. Twelve enzymatic systems (AAT, ADH, EST, GCDH, G3PDH, GPI, IDH, LDH, MDH, ME, PGM and SOD) were analyzed, which allowed to score 22 loci. Only lociAat-2, Est-3 and Mdh-C showed polymorphism. The two samples differed in allele frequencies at the three polymorphic loci. The average expected heterozygosity for all loci was 0.0806 ± 0.0447 in the Keller River sample. For the São João River morphotype, this value was 0.0489 ± 0.0350. Nei'' s genetic identity and distance between the two populations were respectively 0.9789 and 0.0213. Wright''s FIS , FIT and FST over all loci were estimated as 0.3121, 0.4021 and 0.1309, respectively. We consider that the two morphotypes represent species in statunascendi.  相似文献   

15.
The onset of spring, noted by the timing of wildlife migratory and breeding behaviors, has been occurring earlier over the past few decades. Here, we examine 15 years of loggerhead sea turtle, Caretta caretta, nesting patterns along a 40.5 km beach on Florida's Atlantic coast. This small section of beach is considered to be the most important nesting area for this threatened species in the western hemisphere. From 1989 to 2003, the annual number of nests fluctuated between 13 000 and 25 000 without a conspicuous trend; however, based on a regression analysis, the median nesting date became earlier by roughly 10 days. The Julian day of median nesting was significantly correlated with near‐shore, May sea surface temperatures that warmed an average of 0.8°C over this period. This marine example from warm temperate/subtropical waters represents another response of nature to recent climate trends.  相似文献   

16.
17.
Aim The endoparasites of Sebastes capensis Gmelin are examined over most of its geographical range (coasts of Peru, Chile, Argentina and South Africa) to determine: (1) whether the endoparasite communities of this fish show zoogeographical patterns; and (2) if so, whether there are any relationships between spatial variations in the endoparasite fauna and known zoogeographical patterns for marine free‐living organisms (e.g. prey that are included in the life cycles of endoparasites). Location Fish were captured at nine localities along the Pacific coast of South America, from 11° S in the centre of the Peruvian coast, to 52° S in southern Chile, and also at two localities in the Atlantic Ocean, at 43° S in Argentina, and 34° S in South Africa. Methods From April to September 2003 and April to August 2004, 626 fish were captured. Endoparasites and diet were examined following traditional methods. Cluster analyses were used to evaluate the distribution patterns of the endoparasite communities, and to evaluate similarities in the prey composition per locality. Results The endoparasite fauna of S. capensis consisted of four species widely distributed along the Pacific coast: Ascarophis cf. sebastodis, Anisakis sp., Corynosoma australe, and Pseudopecoelus sp. Other parasites were distributed only in some geographical areas. The species richness of the parasite communities increased with latitude along the Pacific coast, while parasite communities from Argentina and South Africa showed low species richness. Cluster analyses based on endoparasite composition and on prey composition grouped localities in a way consistent with known biogeographical areas for marine free‐living organisms. Main conclusions The endoparasites of S. capensis exhibit a pattern associated with known biogeographical areas for free‐living organisms. The latitudinal increase in endoparasite community richness is associated with changes in prey composition (intermediate hosts) and also possibly with the presence of definitive hosts. Therefore, the biogeographical patterns of prey are considered key determinants of the endoparasite community structure of the host.  相似文献   

18.
Puffins, climate change and fisheries Long term changes in north Atlantic weather leading to climate changes have measurable influences on marine eco systems. Seabirds have to cope with changes in the food web, driven by rising SST and other abiotic factors. The Atlantic Puffin is a good example for this. We can study its breeding success and colony size as measurements for changes in the food resources, mainly sandeels or herring over a wide area from the southern boreal to the arctic waters and from the east to west coast colonies of the Atlantic ocean. The findings show that population changes and breeding success in several seabird species like the Puffin and Common Guillemots or Black‐legged Kittiwakes as well show strong correlations to declining sandeels as a consequence of intensive industrial fishing, changes in SST and plankton, especially the most abundant copepod Calanus finmarchicus, development.  相似文献   

19.
Marine debris is recognised globally as a key threatening process to marine life, but efforts to address the issue are hampered by the lack of data for many marine habitats. By developing standardised protocols and providing training in their application, we worked with >300 volunteer divers from 11 underwater research groups to document the scale of the subtidal marine debris problem at 120 sites across >1000 km of the coast of NSW, Australia. Sampling consisted of replicated 25×5 m transects in which all debris was identified, counted, and, where appropriate, removed. Sites ranged from estuarine settings adjacent to major population centres, to offshore islands within marine parks. Estuaries and embayments were consistently found to be the most contaminated habitats. Fishing-related items (and especially monofilament and braided fishing line) were most prevalent at the majority of sites, although food and drink items were important contributors at sites adjacent to population centres. The results identified damaging interactions between marine debris and marine biota at some key locations, highlighting the need for management intervention to ensure habitat sustainability. This study reinforces the important contribution that volunteers can make to assessing conservation issues requiring broad-scale data collection. In this case, citizen scientists delivered data that will inform, and help to prioritise, management approaches at both statewide and local scales. These initial data also provide an important baseline for longer-term, volunteer-based monitoring programs.  相似文献   

20.
Clinus cottoides is a fish endemic to the coast of South Africa, predominantly inhabiting rock pools. All South African clinids are viviparous, but probably breed throughout the year; as such, their dispersal may be limited, unlike species with pelagic larval stages. We analysed 343 fish from 14 localities on the west, south and east coasts using two mitochondrial genes and the second intron of the S7 ribosomal gene. Mitochondrial DNA analyses recovered significant genetic differentiation between fish populations from the east coast and other sampling locations, with a second break found between Gansbaai and Cape Agulhas on the south coast. Nuclear DNA recovered shallower, but significant, levels of population structure. Coalescent analyses suggested remarkably asymmetrical gene flow between sampling locations, suggesting that the cold Atlantic Benguela Current and Indian Ocean Agulhas counter‐current play important roles in facilitating dispersal. There was no gene flow between the east coast and the other sites, suggesting that these populations are effectively isolated. Divergence times between them were estimated to at least 68 000 years. Neutrality tests and mismatch distributions suggest recent population expansions, with the exception of peripheral western and eastern populations (possibly a consequence of environmental extremes at the edge of the species distribution). Analyses of the current South African marine protected areas network show that it is not connected and that De Hoop, one of South Africa's largest marine reserves, appears to be an important source population of recruits to both the south and southwest coasts.  相似文献   

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