The role of introduced species in the decline of a highly endemic fish fauna in Central Mexico

2018 ◽  
Vol 28 (6) ◽  
pp. 1384-1395 ◽  
Author(s):  
Pablo Gesundheit ◽  
Constantino Macías Garcia
Keyword(s):  
Introduced Species ◽  
Fish Fauna ◽  
Central Mexico ◽  
Endemic Fish

scholarly journals Ichthyofauna of streams from the lower Iguaçu River basin, Paraná State, Brazil

2016 ◽  
Vol 16 (3) ◽  
Author(s):  
Crislei Larentis ◽  
Rosilene Luciana Delariva ◽  
Louise Cristina Gomes ◽  
Dirceu Baumgartner ◽  
Igor Paiva Ramos ◽  
...  
Keyword(s):  
River Basin ◽  
Fish Fauna ◽  
Main Channel ◽  
Indicator Species Analysis ◽  
Irreversible Loss ◽  
Species Analysis ◽  
Geomorphological Processes ◽  
Nmds Analysis ◽  
Iguaçu River

Abstract The drainages of the Iguaçu River basin, as well as the main channel of the river, have peculiar characteristics resulting from geomorphological processes in this area, including the formation of the Iguaçu River Falls. This slope in the lower portion of the basin is a biogeographical barrier to many organisms. In this study was inventoried the fish fauna of streams of the lower Iguaçu River basin, evaluating possible differences in the species composition upstream and downstream of this biogeographical barrier. Sampling were conducted between 2004 and 2013, in five streams, three upstream and two downstream of the Iguaçu River Falls, using electrofishing. The nMDS analysis was run to investigate possible groupings of similar fauna between the streams sampled. The scores of this test were tested as to the significance of groupings with the Hotelling T2 test. The indicator value method (IndVal) was used to detect the distribution of species among the groups of the streams upstream and downstream of the Iguaçu River Falls. We collected 18,908 individuals of six orders, 11 families, and 40 species. Siluriformes and Characiformes had the highest species richness; Cyprinodontiformes presented the highest abundance. Considering the species recorded, 21 are considered natives to the Iguaçu River basin, including 15 endemic, wich were found only in streams upstream of the falls. Additional 18 species were verified only in the streams downstream of such barrier. Four species were common to both stretches. The axis 1 of the nMDS separated two groups: streams upstream (S1, S2 and S3) and streams downstream of the Iguaçu River Falls (S4 and S5). The indicator species analysis also indicated a distinction between the groups of streams, that were significantly different (Hotelling's T2 = 234.36, p ˂ 0.0001). The number of endemic species in the streams upstream of the Falls (15 spp.) evidences a significant effect of isolation promoted by the Iguaçu River Falls, and confirms the role of this barrier in the vicariant processes and endemism typical of this basin. These results emphasize the importance of conserving these ecosystems, once the extinction of species in this region means the irreversible loss of them.

scholarly journals Ecological interrelations of Rapana venosa (Gastropoda: Muricidae) with ichthyofauna in the Black Sea

2016 ◽  
Vol 1 (4) ◽  
pp. 76-77
Author(s):  
I. P. Bondarev
Keyword(s):  
Black Sea ◽  
Marine Ecosystem ◽  
Fish Fauna ◽  
The Black Sea ◽  
Sandy Bottom ◽  
Rapana Venosa ◽  
New Information ◽  
Bottom Zone

Systematic monitoring of ecologically significant species – predatory mollusc Rapana venosa Valenciennes, 1846 populations – is an important part of the Black Sea monitoring. The study of the role of R. venosa in contemporary marine ecosystem is of considerable interest. In June-September 2015-2016 the study of consorting relations of rapana was conducted in situ with a parallel sampling by diver. In the course of research new information about the interaction of R. venosa with the fish fauna has been obtained. Of particular importance for fishes is the presence of rapana in the sandy bottom zone, where there are no natural shelters, and food resources are limited. The most important for the fish is the presence on the rapana shells of algal fouling and epiphyton. The shells of invader – R. venosa – and its fouling create additional opportunities for the survival of some fish fauna representatives juveniles of the Black Sea. The data obtained extend the concepts of ecological role of mollusc – invader R. venosa, as well as the ecology and ethology of several fish species.

Plant invasions: the role of biotic interactions

2020 ◽  
Keyword(s):  
Introduced Species ◽  
Plant Invasion ◽  
Native Species ◽  
Native Plants ◽  
Biotic Interactions ◽  
Plant Invasions ◽  
Invasion Dynamics ◽  
Experimental Approaches ◽  
Antagonistic Interactions

Abstract This book contains 23 chapters divided into seven parts. Part I reviews the key hypotheses in invasion ecology that invoke biotic interactions to explain aspects of plant invasion dynamics; and reviews models, theories and hypotheses on how invasion performance and impact of introduced species in recipient ecosystems can be conjectured according to biotic interactions between native and non-native species. Part II deals with positive and negative interactions in the soil. Part III discusses mutualistic interactions that promote plant invasions. Part IV describes antagonistic interactions that hinder plant invasions, while part V presents the consequences of plant invasions for biotic interactions among native species. In part VI, novel techniques and experimental approaches in the study of plant invasions are shown. In the last part, biotic interactions and the management of ecosystems invaded by non-native plants are discussed.

Praying to the Predator

2020 ◽  
Vol 2 (2) ◽  
pp. 28-46
Author(s):  
Geoffrey McCafferty ◽  
Sharisse McCafferty
Keyword(s):  
Oral Traditions ◽  
Central Mexico ◽  
Ritual Practice ◽  
Praying Mantis ◽  
Archaeological Investigation ◽  
Culture Area ◽  
Time Period ◽  
Late Postclassic ◽  
Los Grupos

Pacific Nicaragua has long been recognized as a cultural crossroads, with groups of historically documented migrants from central Mexico integrating with Chibchan groups affiliated with Central and South America. This multicultural setting has inspired decades of archaeological investigation, particularly in search of the southeastern frontier of the Mesoamerican culture area. Following ethnohistorical accounts, Nahuat-speaking groups migrated into and colonized the Rivas area in the late Postclassic / Ometepe period (c. 1300–1525 CE). The most prominent ceramic type used to identify this time period was Luna Polychrome, often found in mortuary contexts and therefore currently the best artifact class for inferring Nahua culture and ideology. This paper presents a detailed analysis of sixty Luna vessels. We suggest that the overarching theme of the painted designs relates to the praying mantis. This interpretation coincides with oral traditions identifying the mantis as the “Madre Culebra,” a powerful and revered predator of the insect world and closely affiliated with female symbolic authority. Iconography on some of the more elaborate pots parallels polychrome ceramic female figurines that have been interpreted as ritual practitioners, or shamans, and we suggest a possible correlation between painted designs with visions experienced during trances. Through this analysis we explore the role of ceramic iconography as an expression of ritual practice. Desde hace mucho tiempo, se reconoce el Pacífico nicaragüense como un cruce de caminos cultural, donde hay registros históricos de grupos de migrantes del centro de México que se unió a grupos Chibchan originarios de América Central y del Sur. Este entorno multicultural ha inspirado décadas de investigación arqueológica, que se ha interesado particularmente en definir la frontera sureste de la zona cultural mesoamericana. De acuerdo con relatos etnohistóricos, los grupos de habla nahua emigraron y colonizaron el área de Rivas en el período Posclásico Tardío, también llamado Ometepe (c. 1300–1525 CE). La principal cerámica que se ha usado para identificar esta era fue la del Polícromo Luna, que, ya que se encuentra a menudo en contextos mortuorios, constituye hoy día la mejor clase de artefacto para reconocer la cultura e ideología nahua. Este artículo presenta un análisis detallado de sesenta vasos Luna. Mantenemos que el tema general de los diseños pintados se relaciona con la mantis religiosa. Esta interpretación coincide con las tradiciones orales que identifican a la mantis como la “Madre Culebra”, un depredador poderoso y venerado del mundo de los insectos y estrechamente relacionado con la autoridad simbólica femenina. La iconografía en algunas de las macetas más elaboradas se asemeja a la de las estatuillas femeninas de cerámica policromada, en las que algunos han querido ver a practicantes de rituales o chamanes. Por nuestra parte, proponemos una posible correlación entre los diseños pintados y las visiones típicas de los trances. A través de este análisis, exploramos el papel de la iconografía cerámica como expresión de la práctica ritual. A Nicarágua do Pacífico é reconhecida há muito tempo como uma encruzilhada cultural, com um importante grupo sendo documentado historicamente como migrantes do centro do México, integrando-se a grupos de Chibchan afiliados à América Central e do Sul. Esse cenário multicultural inspirou décadas de investigação arqueológica, particularmente em busca da fronteira sudeste da área cultural mesoamericana. Segundo relatos etno-históricos, grupos falantes de Nahuat migraram para e colonizaram a região de Rivas no período pós-clássico tardio/Ometepe (c. 1300–1525 dC). A cerâmica mais proeminentemente utilizada para diagnosticar esse período de tempo foi o policromo Luna, frequentemente encontrado em contextos mortuários e, portanto, atualmente a melhor classe de artefato para inferir a cultura e a ideologia de Nahua. Este artigo apresenta uma análise detalhada de sessenta recipientes Luna. Sugerimos que o tema dominante dos desenhos pintados esteja relacionado ao louva-a-deus. Essa interpretação coincide com tradições orais que identificam o louva-a-deus como a “Madre Culebra”, uma predadora poderosa e reverenciada do mundo dos insetos e intimamente afiliada à autoridade simbólica feminina. A iconografia de alguns dos vasos mais elaborados é paralela às figuras femininas de cerâmica policromada que foram interpretadas como praticantes de rituais, ou xamãs, e sugerimos uma possível correlação entre desenhos pintados e visões experimentadas durante os transes. Através desta análise, exploramos o papel da iconografia cerâmica como expressão da prática ritual.

STUDIES ON VARIATION IN PATHOGENICITY IN LEAF RUST OF WHEAT, PUCCINIA TRITICINA ERIKSS.

1949 ◽  
Vol 27c (5) ◽  
pp. 191-202 ◽  
Author(s):  
A. M. Brown ◽  
T. Johnson
Keyword(s):  
Leaf Rust ◽  
Introduced Species ◽  
Yellow Rust ◽  
Puccinia Triticina ◽  
Two Factors ◽  
Physiologic Races

In experiments designed to clarify the causes of the pathogenic changes that have recently been encountered in leaf rust of wheat, two factors were given consideration, (1) the possibility that nuclear exchanges might occur between the mycelia of different races in the uredial stage, and (2) the possible role of Thalictrum species in originating new rust strains. Infection studies with mixtures of races 9 and 15 and mixtures of races 5 and 9 did not produce any evidence that these races could interchange nuclei and thus initiate new pathogenic strains of leaf rust.In greenhouse infection tests with native Thalictrum spp., aecia were produced on T. dasycarpum, pycnia only on T. dioicum and T. polygamum, while no infection of T. venulosum took place. In similar tests with the introduced species T. glaucum and T. dipterocarpum, abundant production of aecia occurred on both species. In out-of-doors inoculation tests with T. dasycarpum and T. venulosum, no infection of these two species took place, whereas, under the same conditions, heavy aecial production occurred on the introduced species T. glaucum.Selfing studies in which Thalictrum glaucum was infected with known physiologic races have indicated that some races of leaf rust are homozygous, and others heterozygous for pathogenic characters. A culture of race 5 appeared to be homozygous, whereas a culture of race 3 was heterozygous, giving rise to races 3, 15, 32, 68, and three undescribed races. A culture of race 76 was heterozygous for both pathogenicity and urediospore color. Aeciospores of this race produced uredia of two different shades of yellow in addition to uredia of normal color. Aeciospores derived from teliospores collected in the field also gave rise to uredial strains of yellow spore color. Most of the yellow rust strains were decidedly low in pathogenic vigor.

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