scholarly journals Microsatellite variation and population genetic structure of a neotropical endangered Bryconinae species Brycon insignis Steindachner, 1877: implications for its conservation and sustainable management

2009 ◽  
Vol 7 (3) ◽  
pp. 395-402 ◽  
Author(s):  
Cristianne Kayoko Matsumoto ◽  
Alexandre Wagner Silva Hilsdorf
Keyword(s):  
Genetic Structure ◽  
Genetic Variability ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Food Resource ◽  
Southeastern Brazil ◽  
Captive Population ◽  
Wild Populations ◽  
Isolated Populations ◽  
Microsatellite Variation

Piabanha (Brycon insignis) is a freshwater fish species from the drainages in Southeastern Brazil. During the 1950s, it was an important economic and food resource for local populations, but dramatic and continuous environmental degradation seriously jeopardized the B. insignis populations in the region. Microsatellite markers were used to assess the genetic structure of wild populations of B. insignis and compare the genetic variability and integrity of the wild populations with a captive population. Samples of DNA from 208 specimens from geographically isolated populations were analyzed. Population genetic structure was investigated using F ST, R ST estimates as well as AMOVA. All five loci used in this study were polymorphic with observed heterozygosity ranging from 0.77 (± 0.15) to 0.88 (± 0.07) in the wild population and 0.90 (± 0.09) in the captive population and the allelic richness average were 7.56 (± 0.27) and 5.80 (± 1.02), respectively. Overall genetic differences were significantly partitioned among populations (F ST = 0.072, p = 0.034). Evidence of a genetic bottleneck was found in some of the wild populations, but especially in the captive population. The results showed that genetic variability still can be found in B. insignis populations which are currently structured possibly due to anthropic actions. The implications of these findings for the management and conservation of B. insignis populations are discussed.

Genotypic variation among Gammarus fasciatus (Crustacea: Amphipoda) from the Great Lakes - St. Lawrence River: implications for the conservation of widespread freshwater invertebrates

2000 ◽  
Vol 57 (9) ◽  
pp. 1843-1852 ◽  
Author(s):  
Ian D Hogg ◽  
Yves de Lafontaine ◽  
John M Eadie
Keyword(s):  
Genetic Structure ◽  
Genetic Variability ◽  
Great Lakes ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Environmental Changes ◽  
Quebec City ◽  
Gammarus Fasciatus ◽  
Low Levels ◽  
St Lawrence River

We examined the population genetic structure of the amphipod Gammarus fasciatus (Crustacea: Amphipoda) over two years from a total of 11 sites within the Great Lakes - St. Lawrence River system using allozyme electrophoresis. In 1995, we examined differences within the St. Lawrence River (Cornwall to Quebec City), and in 1996, we focused on larger scale, whole-system differences from Lake Superior to Lake Champlain. We found very low levels of genetic differentiation among sites (Wright's FST < 0.03). This was not unexpected for an active disperser in a relatively contiguous system. However, we also found low levels of genetic variability within sites (Hobs = 0.07- 0.15), a result that was not anticipated. We surveyed the available literature on gammarid and other amphipods and found that limited genetic variability is characteristic of continuously distributed taxa, contrary to the expectations of current conservation theory. This is potentially of concern, especially in light of recently reported declines of G. fasciatus at several locations within the St. Lawrence River and Great Lakes. Given the importance of species such as G. fasciatus in aquatic food webs, further work is clearly needed on the consequences of population genetic structure to species' responses to novel environmental changes (e.g., exotic species introductions).

Microsatellite Variation Indicates Population Genetic Structure of Bocaccio

2004 ◽  
Vol 24 (4) ◽  
pp. 1189-1202 ◽  
Author(s):  
Andrew P. Matala ◽  
A. K. Gray ◽  
A. J. Gharrett ◽  
M. S. Love
Keyword(s):  
Genetic Structure ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Microsatellite Variation

Resolving distribution and population fragmentation in two leaf-tailed gecko species of north-east Australia: key steps in the conservation of microendemic species

2018 ◽  
Vol 66 (2) ◽  
pp. 152 ◽  
Author(s):  
Lorenzo V. Bertola ◽  
Megan Higgie ◽  
Conrad J. Hoskin
Keyword(s):  
Genetic Structure ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Mitochondrial Gene ◽  
Isolated Populations ◽  
Distribution Models ◽  
Genetic Structuring ◽  
North East ◽  
Management Actions ◽  
Key Steps

North Queensland harbours many microendemic species. These species are of conservation concern due to their small and fragmented populations, coupled with threats such as fire and climate change. We aimed to resolve the distribution and population genetic structure in two localised Phyllurus leaf-tailed geckos: P. gulbaru and P. amnicola. We conducted field surveys to better resolve distributions, used Species Distribution Models (SDMs) to assess the potential distribution, and then used the SDMs to target further surveys. We also sequenced all populations for a mitochondrial gene to assess population genetic structure. Our surveys found additional small, isolated populations of both species, including significant range extensions. SDMs revealed the climatic and non-climatic variables that best predict the distribution of these species. Targeted surveys based on the SDMs found P. gulbaru at an additional two sites but failed to find either species at other sites, suggesting that we have broadly resolved their distributions. Genetic analysis revealed population genetic structuring in both species, including deeply divergent mitochondrial lineages. Current and potential threats are overlain on these results to determine conservation listings and identify management actions. More broadly, this study highlights how targeted surveys, SDMs, and genetic data can rapidly increase our knowledge of microendemic species, and direct management.

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