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1.
A hairless adult male southern sea lion (Otaria flavescens) was sighted at Sea Lion Island, Falkland Islands, on the 14th of August 2009. The sea lion was observed on several further
occasions and was defending a small harem consisting of four females. To our knowledge, this is the first report of an apparently
healthy sea lion being entirely hairless with the exception of vibrissae on the muzzle. 相似文献
2.
3.
Predation by fur seals and sea lions has been identified, among others, as a potential cause of the declines in rockhopper
penguin populations. Here, we report a multiple predation event of southern rockhopper penguins Eudyptes chrysocome by South American sub-adult male sea lions Otaria flavescens at Staten Island, Argentina. The sea lions attacked and preyed on penguins mostly using a wait and rush tactic at sea, but
in some cases, penguins were also pursued on land. Although observations suggested that only a few sea lions are involved
in predation, further research is necessary to elucidate the importance of this predation in the rate of population decline. 相似文献
4.
In the South American sea lion (Otaria flavescens), a polygynous species with a high degree of sexual dimorphism, pups form groups during maternal foraging trips. The aim of this study was to investigate the existence of sexual differences in aggregation behavior and association patterns in O. flavescens pups at Isla de Lobos, Uruguay, during the first 2 mo of life. Scan samplings of marked pups were conducted every hour from 0700 to 1800 to register behavior. Association patterns were analyzed in SOCPROG (using the Half-Weight Index of Association). We did not find significant sex differences in any variable (time spent in groups, average group size, time interacting with other pups, and time in groups at sea). Each pup showed preference for at least one partner. Associations between individuals of the same and different sex were not significantly different. As expected, during the first month, pups associated more strongly with pups born in the same zone than with those born in a different zone. This research provides new evidence on the development of social behavior in otariids and serves as a basis for future studies focusing on sexual differences in pup behavior and association patterns among individuals (e.g., related with kinship). 相似文献
5.
A new species of Volvocisporium (Ustilaginomycota, Microstromatales) has been found on Grewia cf. flavescens (Tiliaceae) in Namibia. V. grewiae is the second representative of this genus worldwide and the first one from the African continent based on morphological
and molecular data.
Taxonomical novelties
Volvocisporium grewiae Ritschel & Oberw. 相似文献
6.
A comparison of Dichodontium flavescens (Dicks.) Lindb. and D. pellucidum (Hedw.) Lindb. (Bryopsida)
《Journal of bryology》2013,35(3):215-221
AbstractFifty-three herbarium samples of the genus Dichodontium, originating from 15 countries in Europe and North America, were examined to critically assess new distinguishing characters between D. flavescens and D. pellucidum. The examination, including SEM, revealed some new characteristics in the gametophyte, notably leaf shape, leaf length: width ratio, and width of the nerve, permitting accurate determinations even on sterile material. D. flavescens is recognized here as a distinct species. 相似文献
7.
Athanasios Athanasiadis 《Marine Biology Research》2016,12(5):551-558
Type material of Lithothamnion flavescens Kjellman, originally described from Karlsøy (Troms) and Karmakul Bay (Novaya Zemlya), is re-examined and a lectotype is selected. Type specimens and other collections from NW Spitsbergen and North Norway possess distinctive characters of the genus Leptophytum, including the development of flattened epithallial cells, short subepithallial cells, and simple spermatangial structures. Leptophytum flavescens (Kjellman) comb. nov. resembles the generitype Leptophytum laeve, differing in having: (1) a thicker perithallium, to 900?µm (vs. 350?µm in L. laeve), that embeds older conceptacles, and (2) non-differentiated (in size or shape) pore cells of multiporate roofs. An epitype for L. laeve is also selected, which consolidates the status of this species and the genus, in agreement with the current literature and all publications prior to 1996. 相似文献
8.
Juan I. Túnez Humberto L. Cappozzo Maximiliano Nardelli Marcelo H. Cassini 《Genetica》2010,138(8):831-841
The north-central Patagonian coast is the sea lions most abundant area in Argentina. As occurs along the entire Atlantic coast,
the distribution of breeding colonies at this smaller geographical scale is also patchy, showing at least three areas with
breeding activity. We study the genetic structure and historical population dynamics of the species in five colonies in this
area, analysing a 508 base-pair segment of the D-loop control region. Otaria flavescens showed 10 haplotypes with 12 polymorphic sites. The genealogical relationship between haplotypes revealed a shallow pattern
of phylogeographic structure. The analysis of molecular variance showed significant differences between colonies, however,
pairwise comparisons only indicate significant differences between a pair of colonies belonging to different breeding areas.
The pattern of haplotype differentiation and the mismatch distribution analysis suggest a possible bottleneck that would have
occurred 64,000 years ago, followed by a demographic expansion of the three southernmost colonies. Thus, the historical population
dynamics of O. flavescens in north-central Patagonia appears to be closely related with the dynamics of the Late Pleistocene glaciations. 相似文献
9.
The aim of this work was to analyse those characteristics of the Atlantic coast that are associated with distribution, abundance
and breeding activity of Otaria flavescens at three ecological scales. We followed a research strategy that consists in looking at the variables that are associated
with the pattern of distribution at regional and landscape scales, instead of following local population in time. We used
bibliographic data of censuses carried out between 1946 and 1997 and a Geographic Information System (GIS) to integrate information
proceeding from censuses and different environmental variables. At a regional scale, we found that the distribution of breeding
colonies did not vary in the period of time analysed and was associated with the pattern of occupation of the coast and the
tide width. There was a significant decrease in abundance between 1946 and 1997. In ‘north-central Patagonia’, the segment of coast with the highest number of sea lions in Argentina, distribution of colonies was associated with islands
availability and negatively correlated with places were anthropogenic disturbance was high. At a local scale, breeding colonies
were positive associated with slight slope coasts and negatively associated to rocky beaches. We identify those characteristics
of the coast associated with distribution of breeding colonies of O. flavescens, which operate at different ecological and temporal scales.
Handling editor: K. Martens 相似文献
10.
Raul E. González‐Ittig Paula C. Rivera Silvana C. Levis Gladys E. Calderón Cristina N. Gardenal 《Zoological Journal of the Linnean Society》2014,171(2):457-474
Several species of the genus Oligoryzomys are natural hosts of different hantavirus genotypes affecting humans. The systematics of the genus is confusing, which complicates the identification of the rodent host and hence the potential endemic areas of hantavirus pulmonary syndrome. In this study, we analyse molecular data to infer phylogenetic relationships among Central and South American specimens of Oligoryzomys, and compare our results with previously published data on karyotypic, geographic distribution and host–virus associations to solve contradictory taxonomic reports. We identified 25 clades, each one corresponding to a different putative species. The phylogenetic trees show that Oligoryzomys longicaudatus is strongly related to the Oligoryzomys flavescens complex, which comprises four clades; Oligoryzomys nigripes is related to Oligoryzomys stramineus, Oligoryzomys vegetus is related to Oligoryzomys fulvescens from Central America, and Oligoryzomys brendae is the sister species of Oligoryzomys aff. destructor. We identified the following rodent host–hantavirus genotype relationships: O. longicaudatus–Andes; O. flavescens ‘West'–Bermejo; O. flavescens ‘East'–Lechiguanas; O. nigripes–Juquitiba; Oligoryzomys microtis–Rio Mamore and Rio Mamore‐3; Oligoryzomys chacoensis–Oran; Oligoryzomys costaricencis–Choclo; Oligoryzomys delicatus–Maporal; Oligoryzomys utiaritensis–Castelo dos Sonhos; Oligoryzomys sp. RT2012–Rio Mamore‐4; Oligoryzomys sp. (and not Oligoryzomys fornesi)–Anajatuba. This work, besides contributing to the development of prevention programmes for hantavirus epidemiology in Latin America, represents a comprehensive update of the systematics of the genus Oligoryzomys. © 2014 The Linnean Society of London 相似文献
11.
A new genus, Sidera (Hymenochaetales), is described to accommodate the dimitic polypores Skeletocutis lenis and S. vulgaris, the monomitic polypore Ceriporiopsis lowei, and the monomitic, hydnoid Athelopsis lunata. The genus is characterised by white-rot, whitish resupinate fruiting bodies, crystal rosettes on specialised hyphae, and
allantoid spores. Cinereomyces (Polyporales) is confirmed to be a good genus including C. lindbladii, separate from Diplomitoporus as defined by its type species D. flavescens and the closely related D. crustulinus. Fabisporus is a taxonomic synonym of Diplomitoporus. Poriodontia subvinosa belongs to the Hymenochaetales. 相似文献
12.
Eduardo Pedreros Jaime Gutierrez Pablo Carrasco Renato A. Quiñones 《Marine and Freshwater Behaviour and Physiology》2016,49(2):127-131
The use of fireworks has increased worldwide in recent years. Despite this, their effects on sea lions and similar species are almost undocumented. In this study, we documented some effects of the 2015 New Year’s fireworks on the behavior of South American sea lions (Otaria flavescens), a marine mammal species that utilizes coastal rookeries for breeding, resting, and care and nursing of pups. An immediate cessation of vocalizations followed the start of the fireworks and a significant decrease in the number of sea lions in the colony was registered. This provided evidence that fireworks disrupted the ongoing behavior of the South American sea lion. Further studies will be necessary to determine whether this disruption has negative consequences for these animals or whether they have evolved behavioral mechanisms for dealing with these kinds of short-term disruptive events. 相似文献
13.
《Mammalian Biology》2007,72(4):193-203
Genetic diversity and population structure of two species of South American pinnipeds, Otaria flavescens and Arctocephalus australis, from colonies located along the south-eastern coast of South America, were analysed using mitochondrial DNA haplotypes and compared with two populations of these species from the Pacific coast. A 445 base-pair segment, that included the tRNA-Glu gene (31 bp) and the adjacent cytochrome b gene (414 bp), was amplified using the polymerase chain reaction and sequenced directly. O. flavescens and A. australis showed six and seven haplotypes with 12 and 20 polymorphic sites, respectively. In the Atlantic Ocean there was an individual of A. australis that showed an haplotype that was highly divergent from the others. If this haplotype is excluded, the pattern of haplotype differentiation obtained for both species indicated a possible bottleneck that would have occurred 110,000 years ago, which also affected other pinnipeds. Colonies of the Atlantic and the Pacific did not share haplotypes. This result, based on a limited number of samples for the comparisons between oceans, suggests that populations from both oceans correspond to different evolutionarily significant units. O. flavescens on the Atlantic coast shows two clusters of breeding colonies in Uruguay and Patagonia, separated by a thousand kilometres. Colonies within clusters did not show significant differences in haplotype frequencies, but the difference between the clusters was significant, suggesting that they correspond to different conservation stocks. 相似文献
14.
Preptetos cannoni n. sp. is described from Siganus lineatus from Heron Island on the southern Great Barrier Reef, Australia. Morphological features that are diagnostic of this species
include: a genital pore that is sinistral to the ventral sucker and vitelline follicles that reach anteriorly to at least
the bifurcation of the intestine. This is the first report of a species of the genus Preptetos from Australian waters and from fishes of the genus Siganus. 相似文献
15.
《Journal of bryology》2013,35(4):363-373
AbstractThree new species of Cololejeunea, C. dianae M. Wigginton, C. sanctae-helenae M. Wigginton and C. grossestyla M. Wigginton are described and illustrated from St Helena, South Atlantic Ocean. Details of their distributions are provided, and differences between the new taxa and other species of Cololejeunea are discussed. This is also the first report of the genus Cololejeunea from St Helena. 相似文献
16.
Michael W. Hawkes 《Journal of phycology》1982,18(4):447-454
Acrosymphyton firmum sp. nov., is described from the northeastern coast of North 1., New Zealand. Gametophytes are spring–summer annuals which grow subtidally on cobbles. Thalli are uniaxial; each axial cell bears a whorl of four indeterminate and one determinate branchlets. Indeterminate branchlets are alternately arranged giving the thallus a distichous and feather-like appearance. Numerous corticating rhizoidal filaments are produced from the periaxial and lower whorl branchlet cells. These rhizoids entwine and obscure the main axis as the thallus develops until in the mature plant the axes have a firm consistency and lubricous texture. The carpogonial branch bearing short lateral filaments and auxiliary cell branch with terminal auxiliary cell place this new species in the genus Acrosymphyton Sjöstedt. Of the three described species in the genus, A. firmum is most similar to A. taylori. This is the first report of the genus Acrosymphyton and the only confirmed report of the family Dumontiaceae in New Zealand waters. 相似文献
17.
Although Echinosophora Nakai has been known as a monotypic and endemic genus of Papillionoideae of Fabaceae in Korea, it has been controversial whether it is distinct from or merged with Sophora. To resolve this matter, we conducted molecular phylogenetic analyses using nucleotide sequence data from the plastid rbcL gene and trnL (UAA) intron. Parsimony analysis, using a total of 53 taxa of the Papillionoideae (including E. koreensis [Nakai] Nakai and several species of Sophora and related genera) and using 20 taxa of Caesalpinioideae and Mimosoideae as outgroups, showed that, although the examined species of Sophora are split into two clades, E. koreensis formed a common clade with S. tomentosa (the type species of the genus) and S. flavescens. E. koreensis therefore should be treated as S. koreensis Nakai, and the generic name Echinosophora be eliminated. We also investigated the embryology of S. koreensis (=E. koreensis) and S. flavescens and found that no differences existed between them. Our molecular study, like other studies, strongly suggested that Sophora is polyphyletic. In this study we presented a summary of embryological features of the core Sophora for future critical comparison with related and unrelated taxa. 相似文献
18.
M. C. Watzin K. Joppe‐Mercure J. Rowder B. Lancaster L. Bronson 《Journal of fish biology》2008,73(7):1585-1599
The objectives of this study were to: (1) determine which fishes were consistently eating zebra mussels Dreissena polymorpha in Lake Champlain and document their feeding behaviour and (2) quantify the diet composition of the fish predators that were found to consume zebra mussels. From 2002 to 2005, freshwater drum Aplodinotus grunniens, pumpkinseed Lepomis gibbosus, yellow perch Perca flavescens and rock bass Ambloplites rupestris all consumed zebra mussels at varying frequencies and amounts. Aplodinotusgrunniens and L. gibbosus chewed clumps of zebra mussels, expelling shells, whereas P. flavescens and A. rupestris swallowed small individuals whole. Lepomis gibbosus consumed zebra mussels at the highest frequency (65–89% of prey consumed) and zebra mussels comprised a large part of this fish’s diet (up to 40% by dry mass). Zebra mussels were also an important component of the diet of A. grunniens (up to 59% of the diet by dry mass, 40–63% frequency of consumption). The percentage of the diet comprising zebra mussels in P. flavescens and A. rupestris varied significantly from year to year but never exceeded 10%. Because A. grunniens and L. gibbosus crushed zebra mussels, the nutritional return from consuming zebra mussels would be similar to other prey; for P. flavescens and A. rupestris zebra mussels were only partially digested and the nutritional return would probably be low. As predation on zebra mussels is widespread and significant, it is possible that fish predators could contribute to regulating the population of zebra mussels in Lake Champlain. 相似文献
19.
Maria Bas Ivan Briz i Godino Myrian lvarez Damin G. Vales Enrique A. Crespo Luis Cardona 《Global Change Biology》2019,25(2):404-419
Stable carbon and nitrogen isotope ratios in the skeletal elements of both ancient and modern marine species from the Beagle Channel were used to compare the structure of Late Holocene and modern food webs, and predict potential changes as a result of a Sea Surface Temperature (SST) increase in the region. Complementary, ancient and modern shells of limpets and mussels were isotopically analysed to explore changes in the isotopic baseline and compare marine food webs through time after an appropriate correction for baseline shifts. Results confirmed a declining pattern of marine primary productivity during the Late Holocene in the Beagle Channel. In general, the isotopic niches overlapped largely in the ancient food web in comparison to the current marine one, with the exception of that of cormorants (Phalacrocorax sp.). Our data suggest that all the species that have undergone intense human exploitation (Arctocephalus australis, Otaria flavescens and Merluccius sp.) significantly increased their trophic levels. The most important finding of this work was the very high isotopic overlap between snoek (Thyrsites atun) and hake (Merluccius sp.) during the Late Holocene. Increasing SST as a result of global warming could favour the recolonization of the southern South‐Western Atlantic Ocean by snoek from the South‐Eastern Pacific Ocean, with a potential impact on the landings of the economically important Argentine and Austral hake. These findings highlight the relevance of using zooarchaeological remains for providing predictions about marine food webs changes in the near future. 相似文献
20.
Variation in isozyme patterns from ten populations of the Korean endemic Lycoris species was used to test the hypothesis that L. flavescens originated from natural hybridization between diploid L. chinensis and L. sanguinea var. koreana. Lycoris sanguinea var. koreana shows fixed heterozygosity at four of nine loci assayed, suggesting that this species is an allotetraploid instead of a diploid.
Electrophoretic data suggest that Lycoris flavescens is an allotriploid species derived from the hybridization between diploid L. chinensis and tetraploid L. sanguinea var. koreana. The patterns of allelic distribution in populations of L. flavescens suggest multiple origins of the allotriploid. Within the L. flavescens complex, our isozyme data support the recognition of two taxa, L. flavescens and a recently recognized species, L. uydoensis.
Received August 28, 2000 Accepted December 27, 2000 相似文献