scholarly journals Evolving in islands of mud: old and structured hidden diversity in an endemic freshwater crayfish from the Chilean hotspot

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pedro F. Victoriano ◽  
Guillermo D’Elía
Keyword(s):  
Southeastern Brazil ◽  
Freshwater Crayfish ◽  
South American ◽  
Southern Chile ◽  
Effective Population ◽  
Conservation Units ◽  
Genetic Groups ◽  
The Pacific ◽  
Conservation Actions ◽  
Andean Uplift

AbstractParastacus is a genus of South American freshwater crayfishes disjunctively distributed in southern Chile, Northern Argentina, Uruguay and Southeastern Brazil. Parastacus pugnax is a Chilean endemic distributed along 700 km of latitude in central-southern Chile from the Pacific coast to the Andean piedmont, which is intensively captured for consumption for local communities. Considering the habitat (wet meadows) and natural history (primary burrower, non-migrant) of the species, we tested a hypothesis of highly structured genetic diversity using mtDNA of 465 specimens gathered at 56 localities across the species range. The crown age of P. pugnax was estimated at 38 Ma, predating the main Andean uplift. The genetic variation of P. pugnax is large and geographically structured. In some cases, genetic groups do not match basin limits, suggesting a previous to current dynamic of basin evolution. The uncovered intraspecific main lineages have different demographic histories. A latitudinal cline in past effective population size reduction suggests environmental singularities with a glacial effect in the southern populations. We suggest adding morphologic and more genetic data in order to assess species limits. Our results contribute to improve future conservation actions for this taxon, providing basic information to delimit conservation units.

INTERSEXUALITY IN THE FRESHWATER CRAYFISH SAMASTACUS SPINIFRONS (PHILIPPI, 1882) (DECAPODA, PARASTACIDAE)

Crustaceana ◽  
1999 ◽  
Vol 72 (3) ◽  
pp. 325-337 ◽  
Author(s):  
Erich Rudolph
Keyword(s):  
Freshwater Crayfish ◽  
South American ◽  
Southern Chile ◽  
Morphometric Analyses ◽  
Males And Females ◽  
Normal Males

AbstractSamastacus spinifrons, a South American freshwater crayfish, has always been characterized as gonochoric in the literature. Yet, in 1989, a specimen with anomalous sexual characters was captured in the river Hueyusca. Since then, 13 other specimens showing such anomalous features have been collected in various rivers in the Osorno province, southern Chile. Anatomical dissections disclosed that 4 of them had testes; 4 others had ootestes and 5 had ovaries. Further, all the specimens had gonoducts and gonopores of both sexes, except in one of those with ovaries, wich had oviducts only. Morphometric analyses of abdomens of normal males and females, in comparison with those of intersexual specimens showed that the latter have abdomens with male characteristics. These conditions are all described, the frequency of the phenomenon is reported and a possible explanation for its occurrence is proposed. El camaron de rio de Sudamerica, Samastacus spinifrons, siempre ha sido caracterizado como gonocorico por la literatura. Sin embargo, en 1989 se capturo en el rio Hueyusca un especimen con caracteres sexuales anomalos. Desde entonces, se han colectados otros 13 especimenes con caracteres anomalos en varios rios de la provincia de Osorno, en el sur de Chile. Las disecciones anatomicas demostraron que 4 de ellos tenian testiculos, otros 4 tenian ovotestis, y 5 tenian ovarios. Ademas, todos tenian gonoductos y gonoporos de ambos sexos, excepto uno de aquellos con ovarios que solo tenia oviductos. Analisis morfometricos de los abdomenes de los machos y hembras normales, comparados con aquellos de especimenes intersexo demostraron que estos ultimos tienen un abdomen con caracteristicas masculinas. Se describen todas estas condiciones, se comunica la frecuencia de ocurrencia de este fenomeno y se propone una probable explicacion para el.

scholarly journals Comprehensive genotyping of a Brazilian cassava (Manihot esculenta Crantz) germplasm bank: insights into diversification and domestication

2021 ◽  
Vol 134 (5) ◽  
pp. 1343-1362
Author(s):  
Alex C. Ogbonna ◽  
Luciano Rogerio Braatz de Andrade ◽  
Lukas A. Mueller ◽  
Eder Jorge de Oliveira ◽  
Guillaume J. Bauchet
Keyword(s):  
Population Genetics ◽  
Population Structure ◽  
Manihot Esculenta ◽  
Ex Situ ◽  
Germplasm Bank ◽  
Effective Population ◽  
Manihot Esculenta Crantz ◽  
Genetic Groups ◽  
Population Structure Analysis ◽  
Modern Breeding

Abstract Key message Brazilian cassava diversity was characterized through population genetics and clustering approaches, highlighting contrasted genetic groups and spatial genetic differentiation. Abstract Cassava (Manihot esculenta Crantz) is a major staple root crop of the tropics, originating from the Amazonian region. In this study, 3354 cassava landraces and modern breeding lines from the Embrapa Cassava Germplasm Bank (CGB) were characterized. All individuals were subjected to genotyping-by-sequencing (GBS), identifying 27,045 single-nucleotide polymorphisms (SNPs). Identity-by-state and population structure analyses revealed a unique set of 1536 individuals and 10 distinct genetic groups with heterogeneous linkage disequilibrium (LD). On this basis, a density of 1300–4700 SNP markers were selected for large-effect quantitative trait loci (QTL) detection. Identified genetic groups were further characterized for population genetics parameters including minor allele frequency (MAF), observed heterozygosity $$({H}_{o})$$ ( H o ) , effective population size estimate $$\widehat{{(N}_{e}}$$ ( N e ^ ) and polymorphism information content (PIC). Selection footprints and introgressions of M. glaziovii were detected. Spatial population structure analysis revealed five ancestral populations related to distinct Brazilian ecoregions. Estimation of historical relationships among identified populations suggests an early population split from Amazonian to Atlantic forest and Caatinga ecoregions and active gene flows. This study provides a thorough genetic characterization of ex situ germplasm resources from cassava’s center of origin, South America, with results shedding light on Brazilian cassava characteristics and its biogeographical landscape. These findings support and facilitate the use of genetic resources in modern breeding programs including implementation of association mapping and genomic selection strategies.

scholarly journals Genetic diversity and kinship relationships in one of the largest South American fur seal ( Arctocephalus australis ) populations of the Pacific Ocean

2021 ◽  
Author(s):  
Josefina Gutiérrez ◽  
Mauricio Seguel ◽  
Pablo Saenz‐Agudelo ◽  
Gerardo Acosta‐Jamett ◽  
Claudio Verdugo
Keyword(s):  
Genetic Diversity ◽  
Pacific Ocean ◽  
South American ◽  
The Pacific ◽  
Fur Seal ◽  
The Pacific Ocean

scholarly journals Deep genetic structure at a small spatial scale in the endangered land snail Xerocrassa montserratensis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Cristina Català ◽  
Vicenç Bros ◽  
Xavier Castelltort ◽  
Xavier Santos ◽  
Marta Pascual
Keyword(s):  
Genetic Structure ◽  
Land Snail ◽  
Snail Species ◽  
Small Spatial Scale ◽  
Geographic Ranges ◽  
Genetic Groups ◽  
Species Of Conservation Concern ◽  
Conservation Actions ◽  
Conservation Concern ◽  
Single Locality

AbstractSpecies with small geographic ranges do not tend to have a high genetic structure, but some land snail species seem to be an exception. Xerocrassa montserratensis, an endangered land snail endemic to Catalonia (northeastern Iberian Peninsula), is an excellent model to study the processes affecting the phylogeography of specialized species of conservation concern. This species is restricted to xerophilous stony slopes and occurs within a small and fragmented area of ca. 500 km2. We sequenced the COI barcode region of 152 individuals from eight sites covering the entire range of the species. We found four genetic groups mostly coincident with their geographic distribution: a central ancestral group containing shared haplotypes among five localities and three groups restricted to a single locality each. Two of these derived groups were geographically and genetically isolated, while the third and most differentiated group was not geographically isolated. Geomorphologic and paleoclimatic processes during the Pleistocene can explain the divergence found between populations of this low dispersal species with historical fragmentation and secondary contacts. Nonetheless, recent passive large dispersal through streams was also detected in the central group. Overall, our study uncovered four evolutionary units, partially matching morphologically described subspecies, which should be considered in future conservation actions.

A new genus and species of groundwater isopod of the family Protojaniridae (Isopoda: Asellota: Gnathostenetroidoidea) from southern Chile

Zootaxa ◽  
2021 ◽  
Vol 4966 (5) ◽  
pp. 550-562
Author(s):  
JORGE PÉREZ-SCHULTHEISS ◽  
GEORGE D. F. WILSON
Keyword(s):  
New Genus ◽  
South American ◽  
New Taxon ◽  
Southern Chile ◽  
New Genus And Species ◽  
The Third ◽  
The Family ◽  
Apical Lobe ◽  
Antennal Scale ◽  
Freshwater Springs

A new asellotan isopod of the family Protojaniridae Fresi, Idato & Scipione, 1980 is described from freshwater springs in the Osorno province, Los Lagos region, southern Chile. Wiyufiloides osornoensis gen. & sp. n. is the third South American protojanirid species and the first known groundwater isopod in Chile. The new genus and species is principally characterized by the presence of a vestigial antennal scale, a strongly subchelate pereiopod I and the absence of an apical lobe on the protopod of pleopod II. The new taxon is described in detail and figures are given. 

Seriemas: A Literature Assessment and Recommendations for Future Research

2021 ◽  
Author(s):  
Diego Méndez ◽  
Zackery Szymczycha ◽  
Jeremiah Sullivan ◽  
Christopher J. W. McClure
Keyword(s):  
Keyword Search ◽  
Conservation Status ◽  
Future Research ◽  
South American ◽  
South American Species ◽  
Systematic Map ◽  
Conservation Actions ◽  
Forested Areas ◽  
Causes Of Mortality ◽  
Territorial Behaviors

ABSTRACT Red-legged Seriemas (Cariama cristata) and Black-legged Seriemas (Chunga burmeisteri) are two exclusively South American species that inhabit open and sparsely forested areas. Seriemas have been recently included with the raptors based on ecological and evolutionary evidence. Viewing seriemas as raptors is nontraditional and might be controversial. Therefore, further information regarding the evolution, taxonomy, morphology, and ecology of these birds will clarify the validity of their consideration as raptors. Here we present a review of the published information on seriemas, and discuss future research for these newly adopted raptors. To conduct our review, we developed a systematic map and searched all databases available within Clarivate Analytics' Web of Science, performed a keyword search of Google Scholar, and included the corresponding bibliographies from the Birds of the World website. We reviewed 98 studies, and found that the Red-legged Seriema was the subject of more studies than the Black-legged Seriema. Overall, Brazil and Argentina were the site of most studies. The majority of studies examined physiology (48), followed by behavior (37), threats to the survival of these species (36), and demography (27), while smaller numbers of studies examined stressors (e.g., habitat changes, causes of mortality and injury such as predation, hunting, etc.) (20), and conservation actions (10). Patterns of study categorizations were similar for both species, and the distribution of studies across months was also fairly even for both species. This is the first study to systematically review and assess the published information on seriemas. Our results show the topics and locations on which past studies have focused, and highlight potentially fruitful avenues for future research. Although threats to seriemas have been identified, these have not been thoroughly assessed; thus, their extent and effects on seriema populations were difficult to ascertain. Future research should focus on testing existing hypotheses regarding seriema feeding, vocalization, social, and territorial behaviors, while documenting natural history. Researchers should build on past investigations while establishing programs to monitor the conservation status of seriemas across their ranges.

Landscape of Migration

2020 ◽  
Author(s):  
Ben Nobbs-Thiessen
Keyword(s):  
Food Security ◽  
South American ◽  
Santa Cruz ◽  
Cash Crop ◽  
Revolutionary Movement ◽  
Export Agriculture ◽  
The Pacific ◽  
Regional Capital ◽  
Tropical Lowlands ◽  
Do So

In the wake of a 1952 revolution, leaders of Bolivia's National Revolutionary Movement (MNR) embarked on a program of internal colonization known as the "March to the East." In an impoverished country dependent on highland mining, the MNR sought to convert the nation’s vast "undeveloped" Amazonian frontier into farmland, hoping to achieve food security, territorial integrity, and demographic balance. To do so, they encouraged hundreds of thousands of Indigenous Bolivians to relocate from the "overcrowded" Andes to the tropical lowlands, but also welcomed surprising transnational migrant streams, including horse-and-buggy Mennonites from Mexico and displaced Okinawans from across the Pacific. Ben Nobbs-Thiessen details the multifaceted results of these migrations on the environment of the South American interior. As he reveals, one of the "migrants" with the greatest impact was the soybean, which Bolivia embraced as a profitable cash crop while eschewing earlier goals of food security, creating a new model for extractive export agriculture. Half a century of colonization would transform the small regional capital of Santa Cruz de la Sierra into Bolivia's largest city, and the diverging stories of Andean, Mennonite, and Okinawan migrants complicate our understandings of tradition, modernity, foreignness, and belonging in the heart of a rising agro-industrial empire.

Morphometrical and molecular evidence suggests cryptic diversity among hookworms (Nematoda: Uncinaria) that parasitize pinnipeds from the south-eastern Pacific coasts

2018 ◽  
Vol 94 ◽  
Author(s):  
M.T. González ◽  
Z. López ◽  
J.J. Nuñez ◽  
K.I. Calderón-Mayo ◽  
C. Ramírez ◽  
...  
Keyword(s):  
Large Subunit ◽  
Principal Component ◽  
Eastern Pacific ◽  
Lsu Rdna ◽  
Molecular Evidence ◽  
South American ◽  
Southern Chile ◽  
The South ◽  
South Eastern ◽  
Neophoca Cinerea

AbstractHookworms of the genus Uncinaria parasitize pinniped pups in various locations worldwide. Four species have been described, two of which parasitize pinniped pups in the southern hemisphere: Uncinaria hamiltoni parasitizes Otaria flavescens and Arctocephalus australis from the South American coast, and Uncinaria sanguinis parasitizes Neophoca cinerea from the Australian coast. However, their geographical ranges and host specificity are unknown. Uncinaria spp. are morphologically similar, but molecular analyses have allowed the recognition of new species in the genus Uncinaria. We used nuclear genetic markers (internal transcribed spacer (ITS) and large subunit (LSU) rDNA) and a mitochondrial genetic marker (cytochrome c oxidase subunit I (COI)) to evaluate the phylogenetic relationships of Uncinaria spp. parasitizing A. australis and O. flavescens from South American coasts (Atlantic and Pacific coasts). We compared our sequences with published Uncinaria sequences. A Generalized Mixed Yule Coalescent (GMYC) analysis was also used to delimit species, and principal component analysis was used to compare morphometry among Uncinaria specimens. Parasites were sampled from A. australis from Peru (12°S), southern Chile (42°S), and the Uruguayan coast, and from O. flavescens from northern Chile (24°S) and the Uruguayan coast. Morphometric differences were observed between Uncinaria specimens from both South American coasts and between Uncinaria specimens from A. australis in Peru and southern Chile. Phylogenetic and GMYC analyses suggest that south-eastern Pacific otariid species harbour U. hamiltoni and an undescribed putative species of Uncinaria. However, more samples from A. australis and O. flavescens are necessary to understand the phylogenetic patterns of Uncinaria spp. across the South Pacific.

scholarly journals The vascular flora of Porto Ferreira State Park: an ecotonal area in São Paulo State, southeastern Brazil

2021 ◽  
Vol 21 (4) ◽  
Author(s):  
Gabriel Pavan Sabino ◽  
Vitor de Andrade Kamimura ◽  
Renan Borgiani ◽  
Rafael Konopczyk ◽  
Ernesto Pedro Dickfeldt ◽  
...  
Keyword(s):  
Riparian Forest ◽  
Vegetation Type ◽  
Sao Paulo ◽  
Southeastern Brazil ◽  
São Paulo ◽  
Vegetation Types ◽  
Conservation Units ◽  
Semideciduous Forest ◽  
Floristic Similarity ◽  
Vascular Flora

Abstract: The Porto Ferreira State Park (PFSP) is located in the State of São Paulo southeastern Brazil, in an intriguing transitional area between the Atlantic Forest and Cerrado - both hotspots of biodiversity - represented mainly by the cerradão (CER), and the seasonal semideciduous forest (SSF), with its alluvial variation vegetation type (riparian forest - RP). Ecotonal areas play an important role in providing ecological and phytogeographic knowledge regarding the flora and vegetation of this region. Despite various studies on the PFSP, knowledge of this region remains fragmented. In this study, we aim to conduct an updated checklist of the PFSP vascular flora, including a compilation of all the studies conducted in this protected area, plus field work carried out by the authors from 2014 to 2017. In addition, given its ecotonal characteristics, we completed a floristic similarity analysis between the PFSP and other floristic surveys that examined the same vegetation types present in this study, to gain a better understanding of their phytogeographic relationships. Overall, 684 species, belonging to 387 genera and 107 families, were recorded. The SSF presented the richest vegetation type (478 species), followed by the CER (418) and the RP (231). The most diverse families were Fabaceae (64 species), Myrtaceae (41), Orchidaceae (39), Rubiaceae (37), Asteraceae (35), Bignoniaceae (26) and Malvaceae (20). Moreover, eight threatened species, at regional and national levels, were found. To date, 412 species have been added to the floristic list produced for the PFSP. The life forms with the highest number of species were trees (286 species), herbs (176) plus shrubs and subshrubs (123). Our research findings indicate floristic patterns with higher levels of similarity among species in geographical proximity, including those in ecotonal areas encompassing different vegetation types. These results rank the PFSP among some of the most species-rich conservation units with seasonal climates, and therefore is of great importance for plant conservation in the southeast of Brazil.

scholarly journals On the Pleistocene Snow-Line Depression in the Arid Regions of the South American Andes

1971 ◽  
Vol 10 (59) ◽  
pp. 255-267
Author(s):  
Stefan L. Hastenrath
Keyword(s):  
Arid Regions ◽  
South American ◽  
The South ◽  
Temperate Latitude ◽  
The Andes ◽  
Western Cordillera ◽  
Snow Line ◽  
The Pacific ◽  
The Arid Regions ◽  
June July

AbstractField observations during a journey through the arid regions of the South American Andes in June-July 1969 are evaluated in conjunction with available air photographs and reports from adjacent regions of the High Andes. Results indicate an increase of the Pleistocene snow-line depression in the western Cordillera from about 700 m at lat. 12° S. to more than 1 500 m at lat. 30° S. The Pleistocene snow-line depression decreases from the Pacific to the Atlantic side of the Andes, but particularly strongly so on the poleward fringe of the arid region. From this geomorphic evidence it is suggested that the atmospheric circulation during the glacial period was characterized by an Equatorward displacement of the boundary between tropical easterlies and temperate-latitude westerlies.

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