Assessment of the population genetic structure of Sphyrna lewini to identify conservation units in the Mexican Pacific

The south-west Australian flora shows a diverse array of evolutionary patterns and exceptionally high species diversity. A significant component of this flora consists of relictual species which often have naturally fragmented and geographically restricted distributions. Many of these species appear to apportion significant levels of genetic diversity among populations. Diversity at both the population and species level presents a major challenge to the development of appropriate conservation strategies for this flora. To be effective these strategies should not only aim to preserve current levels of species diversity, but also consider intraspecific variation and the evolutionary and ecological processes associated with the generation and maintenance of that variation. The identification and characterisation of conservation units, based on population genetic structure and phylogeographic patterns within species, provide a useful basis upon which more general conservation principals can be developed for the maintenance of these processes. Population genetic structure and phylogeographic studies are used to show how conservation units can be identified in Lambertia orbifolia, Acacia anomala, Stylidium coroniforme, Stylidium nungarinense and Banksia cuneata, and taxa from a range of other genera. Determining conservation units in these taxa defines not only suitable units for their conservation but also the appropriate geographical scale for management. These findings indicate the potential this approach can have in determining strategies and priorities for the conservation of the south-west Australian flora.

Download Full-text

Diversity and population genetic structure of Octopus hubbsorum in the Mexican Pacific inferred from mitochondrial DNA sequences

Marine and Freshwater Research ◽

10.1071/mf19382 ◽

2021 ◽

Vol 72 (1) ◽

pp. 35

Author(s):

José de Jesús Dueñas-Romero ◽

Jasmín Granados-Amores ◽

Deivis Samuel Palacios-Salgado ◽

José Francisco Domínguez-Contreras ◽

Juan Ramón Flores-Ortega ◽

...

Keyword(s):

Genetic Structure ◽

Dna Sequences ◽

Population Genetic Structure ◽

Population Genetic ◽

Isolation By Distance ◽

Population Expansion ◽

Western Coast ◽

Study Region ◽

Mexican Pacific ◽

Clustering Model

Octopus hubbsorum is the most commonly captured species of octopus on the western coast of Mexico. Despite the commercial importance of this species, management information remains scarce. We determined the genetic diversity and population genetic structure of O. hubbsorum by using mtDNA sequences (COI and ND5). The population structure was not supported by AMOVA or a spatial clustering model. Furthermore, an isolation by distance model did not explain our data. Three haplogroups were detected using a Bayesian assignment; however, the distribution of these haplogroups did not differ among the sampling sites. Our results indicated historical processes of a sudden population expansion, as has been reported for other species in the study region as consequence of climatic changes. However, this expansion did not affect the distribution of the mitochondrial lineages analysed in the study. The weak population genetic structure in O. hubbsorum associated with the life history of the species can explain our results. We suggest that to expand knowledge regarding the genetic structure and population dynamics of O. hubbsorum throughout its range, markers such as microsatellites or single-nucleotide polymorphisms (SNPs) are needed. Thus, on the basis of the information available, the studied population should be assumed to have a weak genetic structure.

Download Full-text