scholarly journals Two decades of colonization of the urban environment of Porto Alegre, southern Brazil, by Drosophila paulistorum (Diptera, Drosophilidae)

2008 ◽  
Vol 98 (3) ◽  
pp. 329-338 ◽  
Author(s):  
Ana Cristina L. Garcia ◽  
Victor Hugo Valiati ◽  
Marco S. Gottschalk ◽  
Cláudia Rohde ◽  
Vera Lúcia da S. Valente

Drosophila paulistorum Dobzhansky & Pavan, 1949 had initially been considered absent in anthropogenically disturbed environments, but in 1985 the detection of the species in Porto Alegre city, southern Brazil, suggested its potential to colonize new habitats and laid the foundations for ecologic studies on this species' populations. This study followed the variations in D. paulistorum populations in this town almost 20 years after its first local record. Drosophilid specimens were collected in sites with different urbanization grades and the results point to the expressive decline in D. paulistorum populations in Porto Alegre. This decline may be linked to urban growth and to naturally driven population decline, as imputed to climatic changes like variations in maximum and minimum temperatures as a consequence of a global climate warming. Also, the recent introduction of exotic species Zaprionus indianus Gupta, 1970 seems to play a role in this scenario, changing the interactions between native species.

2015 ◽  
Author(s):  
Piter K Boll ◽  
Ilana Rossi ◽  
Silvana V Amaral ◽  
Ana Leal-Zanchet

Invasive species establish successfully in new habitats especially due to their generalist diet and release of natural enemies. However, native species may also adapt to use new elements in their ecosystem. The planarian Endeavouria septemlineata, first recorded in Hawaii, was later registered in Australia and Brazil. Recently we found it in human-disturbed areas in southern Brazil and here we investigate its interactions with other invertebrates both in the field and in the laboratory. We observed the species in the field during collecting activities and maintained some specimens alive in small terraria in the laboratory, where we offered different invertebrate species as potential prey and also put them in contact with native land planarians in order to examine their interaction. Both in the field and in the laboratory, E. septemlineata showed a gregarious behavior and was found feeding on woodlice, millipedes, earwigs and gastropods. In the laboratory, specimens did not attack live prey, but immediately approached dead specimens, indicating a scavenging behavior. Four native land planarians of the genus Obama and two of the genus Paraba attacked and consumed E. septemlineata, which, after the beginning of the attack, tried to escape by tumbling or using autotomy. As a scavenger, E. septemlineata would impact the populations of species used as food, but could possibly exclude native scavengers by competition. On the other hand, its consumption by native land planarians may control its spread and thus reduce its impact on the ecosystems.


1997 ◽  
Vol 20 (4) ◽  
pp. 567-581 ◽  
Author(s):  
Victor Hugo Valiati ◽  
Vera Lucia S. Valente

Drosophila paulistorum populations colonizing the urban area of Porto Alegre, southern Brazil, were studied with the objective of characterizing their chromosomal polymorphism in this new environment. Despite being geographically and ecologically marginal and the fact that the colonization of the urban area seems to be a recent event, the populations showed a large number of inversions on all chromosome arms. Differences regarding inversion frequencies and percentage of heterozygosis were found when we compared the samples with respect to geographical, microenvironmental and temporal aspects. Such differences, however, could be attributed to both selective and stochastic factors


2015 ◽  
Author(s):  
Piter K Boll ◽  
Ilana Rossi ◽  
Silvana V Amaral ◽  
Ana Leal-Zanchet

Invasive species establish successfully in new habitats especially due to their generalist diet and release of natural enemies. However, native species may also adapt to use new elements in their ecosystem. The planarian Endeavouria septemlineata, first recorded in Hawaii, was later registered in Australia and Brazil. Recently we found it in human-disturbed areas in southern Brazil and here we investigate its interactions with other invertebrates both in the field and in the laboratory. We observed the species in the field during collecting activities and maintained some specimens alive in small terraria in the laboratory, where we offered different invertebrate species as potential prey and also put them in contact with native land planarians in order to examine their interaction. Both in the field and in the laboratory, E. septemlineata showed a gregarious behavior and was found feeding on woodlice, millipedes, earwigs and gastropods. In the laboratory, specimens did not attack live prey, but immediately approached dead specimens, indicating a scavenging behavior. Four native land planarians of the genus Obama and two of the genus Paraba attacked and consumed E. septemlineata, which, after the beginning of the attack, tried to escape by tumbling or using autotomy. As a scavenger, E. septemlineata would impact the populations of species used as food, but could possibly exclude native scavengers by competition. On the other hand, its consumption by native land planarians may control its spread and thus reduce its impact on the ecosystems.


PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1307 ◽  
Author(s):  
Piter K. Boll ◽  
Ilana Rossi ◽  
Silvana V. Amaral ◽  
Ana Leal-Zanchet

Invasive species establish successfully in new habitats especially due to their ability to include new species in their diet and due to the freedom from natural enemies. However, native species may also adapt to the use of new elements in their ecosystem. The planarianEndeavouria septemlineata, first recorded in Hawaii, was later found in Brazil. Recently, we found it in human-disturbed areas in southern Brazil and here we investigate its interactions with other invertebrates both in the field and in the laboratory. We observed the species in the field during collecting activities and hence maintained some specimens alive in small terraria in the laboratory, where we offered different invertebrate species as potential prey and also put them in contact with native land planarians in order to examine their interaction. Both in the field and in the laboratory,E. septemlineatashowed a gregarious behavior and was found feeding on woodlice, millipedes, earwigs and gastropods. In the laboratory, specimens often did not attack live prey, but immediately approached dead specimens, indicating a scavenging behavior. In an experiment using the slugDeroceras laeveand the woodlouseAtlantoscia floridana,there was a higher consumption of dead specimens of woodlice and slugs compared to live specimens, as well as a higher consumption of dead woodlice over dead slugs. Four native land planarians of the genusObamaand one of the genusParabaattacked and consumedE. septemlineata, which, after the beginning of the attack, tried to escape by tumbling or using autotomy. As a scavenger,E. septemlineatawould have no impact on the populations of species used as food, but could possibly exclude native scavengers by competition. On the other hand, its consumption by native land planarians may control its spread and thus reduce its impact on the ecosystem.


2021 ◽  
pp. 1-8
Author(s):  
Michael J Liles ◽  
M Nils Peterson ◽  
Kathryn T Stevenson ◽  
Markus J Peterson

Summary Public preferences for wildlife protection can dictate the success or failure of conservation interventions. However, little research has focused on wildlife preferences among youth or how youth prioritize species-based conservation. We conducted a study of youth between 7 and 20 years old (n = 128) at five local schools situated near critical hawksbill turtle (Eretmochelys imbricata) nesting beaches in El Salvador to determine their wildlife preferences and how they prioritize species for conservation based on five attributes: endemism; use for hunting and fishing; rapid decline in population size; presence around their home; and ecological significance. These Salvadoran youth showed preferences for native over non-native species and tended to rank rapid population decline as the most important attribute for prioritizing wildlife for protection, followed by use for hunting and fishing. Participants in local environmental education activities placed greater importance on species in rapid decline than non-participants, who considered endemism as most important. Overall, these findings reveal how environmental education may successfully promote increased prioritization of imperilled species among youth. Economic payments for conserving hawksbill turtles may link the two top reasons that Salvadoran youth provided for protecting species by compensating for the reduced hunting required to facilitate population stabilization.


2021 ◽  
Author(s):  
Natalia F Versiani ◽  
Larissa L Bailey ◽  
Nielson Pasqualotto ◽  
Thiago F Rodrigues ◽  
Roberta M Paolino ◽  
...  

Abstract The drastic reduction of the Brazilian Cerrado has transformed this savanna hotspot into vast swaths of commodity-based agriculture fields, mainly soybean, sugarcane, and beef-production pasturelands. The resulting habitat loss and fragmentation are the principal factors underlying population decline of native species inhabiting the Cerrado, particularly those with a high demand for space, low population density, and specialized diet, such as the endangered giant anteater (Myrmecophaga tridactyla). Although the species has been studied in protected areas, we know much less about its ability to endure in disturbed landscapes. Here, we analyzed camera-trapping data to estimate a proxy of habitat use (ψ^; occupancy) and detection probabilities of the giant anteater, identifying environmental covariates influencing these parameters in landscapes with intensive agriculture and commercial forestry. We found this species using about half of the study area (model average ψ^ = 0.51, CI = 0.40–0.62), with two predictors strongly influencing habitat use: protected areas and unpaved roads. In turn, detection probability correlates positively with area of open Cerrado and negatively with area of settlements. The species is more likely to use unpaved roads inside protected areas (ψ^ = 0.90, CI = 0.47–0.75), compared to off road sites in the surrounding areas (ψ^ = 0.19, CI = 0.10–0.34). Our findings indicate that giant anteaters are dependent on nature reserves and native vegetation areas existing on private properties, whose protection is regulated by the Brazilian Native Vegetation Protection Law. Given the relative paucity of state-owned protected areas in the Brazilian Cerrado, increasing the adherence of rural owners to this law is, therefore, key for the conservation of the giant anteater. The intense use of unpaved roads might reflect travelling and/or foraging optimization, a behavioral response that, nevertheless, may compound this species’ susceptibility to suffer mortality from roadkill.


2003 ◽  
Vol 51 (5) ◽  
pp. 543 ◽  
Author(s):  
María A. Pérez-Fernández ◽  
Byron B. Lamont

Six Spanish legumes, Cytisus balansae, C. multiflorus, C. scoparius, C. striatus, Genista hystrix and Retama sphaerocarpa, were able to form effective nodules when grown in six south-western Australian soils. Soils and nodules were collected from beneath natural stands of six native Australian legumes, Jacksonia floribunda, Gompholobium tomentosum, Bossiaea aquifolium, Daviesia horrida, Gastrolobium spinosum and Templetonia retusa. Four combinations of soils and bacterial treatments were used as the soil treatments: sterile soil (S), sterile inoculated soils (SI), non-treated soil (N) and non-treated inoculated soils (NI). Seedlings of the Australian species were inoculated with rhizobia cultured from nodules of the same species, while seedlings of the Spanish species were inoculated with cultures from each of the Australian species. All Australian rhizobia infected all the Spanish species, suggesting a high degree of 'promiscuity' among the bacteria and plant species. The results from comparing six Spanish and six Australian species according to their biomass and total nitrogen in the presence (NI) or absence (S) of rhizobia showed that all species benefitted from nodulation (1.02–12.94 times), with R.�sphaerocarpa and C. striatus benefiting more than the native species. Inoculation (SI and NI) was just as effective as, or more effective than the non-treated soil (i.e. non-sterile) in inducing nodules. Nodules formed on the Spanish legumes were just as efficient at fixing N2 as were those formed on the Australian legumes. Inoculation was less effective than non-treated soil at increasing biomass but just as effective as the soil at increasing nitrogen content. Promiscuity in the legume–bacteria symbiosis should increase the ability of legumes to spread into new habitats throughout the world.


2008 ◽  
Vol 6 (2) ◽  
pp. 275-281 ◽  
Author(s):  
Luciano de Oliveira Garcia ◽  
Carlos Eduardo Copatti ◽  
Flávio Wachholz ◽  
Waterloo Pereira Filho ◽  
Bernardo Baldisserotto

In this study we verified data of water temperatures collected by CORSAN-RS from 1996 to 2004 in several cities of the state of Rio Grande do Sul, southern Brazil, and analyzed the possibility of raising the most cultivated fish species in Brazil. The water temperature from 1996 to 2004 was 16 to 28ºC in summer, 17 to 23ºC in fall, 14 to 17ºC (down to 9ºC in the coldest months) in winter and 14 to 21ºC in spring. Native species of this state, such as silver catfish (Rhamdia quelen), traíra (Hoplias malabaricus), dorado (Salminus brasiliensis), pintado (Pimelodus maculatus), as well as carps (family Cyprinidae), are resistant to the low winter temperatures. These species have a lower growth rate in coldest months (winter/spring) but a good development in warmer months (summer/fall), reaching a satisfactory performance throughout the year. In the periods of more intense cold, mortality of some introduced species, such as surubim from Amazon Basin (Pseudoplatystoma sp.), pirapitinga (Piaractus brachypomus), pirarucu (Arapaimas gigas), pacu (Piaractus mesopotamicus), tambaqui (Colossoma macropomum) and Nile tilapia (Oreochromis niloticus) may occur. In addition, as most tropical species have a thermal range for growth and reproduction between 20 to 28ºC, some species may have poor development even in fall. Therefore, water temperature in this state should be considered in the choice of fish species to be cultivated.


2010 ◽  
Vol 8 (2) ◽  
pp. 209-225
Author(s):  
Guilherme Dornelas Camara ◽  
Sueli Goulart ◽  
Rafaela Mendes Reinher

This paper discusses the organizational practices of hip hop groups from Porto Alegre, southern Brazil, as they appropriate foreign experience and rationally guide their social action. The aim of this work is to investigate these practices, based on the formulations of Brazilian sociologist Alberto Guerreiro Ramos, as they are enunciated in the works The Sociological Reduction and The New Science of Organizations. This approach offers fruitful material to broaden the theory and may be subsidiary to this kind of socio-cultural study, explaining why it is pertinent in this field. In this sense, the hip hop movement can be viewed as valuable when it comes to understanding phenomena which, due to (and in spite of) being originally transnational, or even "foreign", act or interact worldwide. Examining the organization practices and social action of these groups also helped identify a concern with the production of cultural artifacts that represent and form a symbolism that is historically and culturally located. Another issue that was broached concerns the market since for those groups it is not a category absent from their struggles and actions, but the economic criteria are incidental in relation to their members' motivation.


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