Strong sexual selection does not induce population differentiation in a fish species with high dispersal potential: the curious case of the worm pipefish Nerophis lumbriciformis (Teleostei: Syngnathidae)

2020 ◽  
Author(s):  
Tito Mendes ◽  
Cidália Gomes ◽  
Nuno Monteiro ◽  
Agostinho Antunes
Keyword(s):  
Sexual Selection ◽  
Population Differentiation ◽  
Change Scenario ◽  
Homogeneous Population ◽  
High Dispersal ◽  
Pelagic Larvae ◽  
Dispersal Vectors ◽  
Dispersal Potential ◽  
Population Structuring ◽  
Limited Dispersal

Abstract High levels of population differentiation are a common demographic pattern in syngnathids, even at small geographical scales. This is probably the end result of the common life history traits observed within the family, involving limited dispersal capabilities and strong habitat dependency. The worm pipefish, Nerophis lumbriciformis, which displays all these characteristics, also presents an additional variable potentially able to promote population differentiation: high sexual selection intensity, especially at the extremes of its distribution. Nevertheless, an early life pelagic stage, which presumable allows for admixture, could prevent population structuring. Here, we assessed the phylogeography of N. lumbriciformis through the amplification of the cytochrome b, 12S and 16S rDNA mitochondrial markers as well as the rhodopsin nuclear marker, performed upon 119 individuals. We observed a genetically homogeneous population with indications of extensive gene flow. We tentatively attribute this finding to the dispersal potential of the species’ pelagic larvae, supported by marine currents acting as major dispersal vectors. We also detected a signal of expansion towards the poles, consistent with the current climate change scenario. Despite the marked latitudinal differences in the phenotype of reproducing worm pipefish, the absence of clear population structuring suggests that phenotypic plasticity can have a significant role in the expression of sexual selection-related traits.

Gene flow, colonisation and demographic history of the flat oyster Ostrea angasi

2005 ◽  
Vol 56 (8) ◽  
pp. 1099 ◽  
Author(s):  
David A. Hurwood ◽  
Mike P. Heasman ◽  
Peter B. Mather
Keyword(s):  
New South ◽  
Demographic History ◽  
New South Wales ◽  
Homogeneous Population ◽  
South Wales ◽  
Base Pair Fragment ◽  
Population Structuring ◽  
History Of ◽  
Natural Range ◽  
Flat Oyster

The Australian flat oyster Ostrea angasi is currently being assessed for its potential as a species for culture in New South Wales. It is considered important to determine the population genetic structure of wild stocks among estuaries before translocation of juveniles (spat) for growout in order to avoid possible deleterious effects of hybridisation of genetically divergent stocks (i.e. outbreeding depression). Five estuaries were sampled in southern New South Wales as well as another four from across the natural range of the species in Australia. Sequence analysis of a 594 base pair fragment of the mitochondrial cytochrome oxidase I gene was used to determine the degree of population structuring inferred from pairwise ΦST estimates and spatial analysis of molecular variance analysis. The analyses revealed that there is no significant genetic differentiation among the sampled New South Wales estuaries (P > 0.05) and all eastern samples represent a geographically homogeneous population. This essentially removes any potential constraints on broodstock sourcing and spat translocation within this region. Although levels of differentiation among all sites varied, little divergence was evident across the entire range of the sample. Furthermore, the study revealed extremely low levels of divergence between O. angasi and its northern hemisphere congener, O. edulis, raising the possibility that O. angasi may have only recently colonised Australian estuaries.

Phylogeography of two freshwater prawn species from far-northern Queensland

2015 ◽  
Vol 66 (3) ◽  
pp. 256 ◽  
Author(s):  
Sofie J. Bernays ◽  
Daniel J. Schmidt ◽  
David A. Hurwood ◽  
Jane M. Hughes
Keyword(s):  
Isolation By Distance ◽  
Distance Effect ◽  
Mantel Test ◽  
Freshwater Prawn ◽  
Freshwater Species ◽  
High Dispersal ◽  
Hierarchy Model ◽  
Limited Dispersal ◽  
Dispersal Abilities ◽  
Low Levels

The distribution of a freshwater species is often dependent on its ability to disperse within the riverine system. Species with high dispersal abilities tend to be widespread, whereas those with restricted dispersal tend to be geographically restricted and are usually given higher conservation priority. Population structure was compared between a widespread freshwater prawn species, Macrobrachium australiense, and a narrow-range endemic freshwater prawn, Macrobrachium koombooloomba. The distribution of M. australiense and M. koombooloomba did not overlap, although suggested historical river-boundary rearrangements indicate that there has been the potential for dispersal into neighbouring catchments. A fragment of the mtDNA CO1 gene was analysed and a Mantel test revealed a significant isolation by distance effect for both species. Significant overall FST values confirmed that both species exhibited low levels of dispersal, a prediction for populations inhabiting a fragmented upland environment. The level of structure in M. australiense is surprising for a widely distributed species. Not all M. australiense populations conformed to the stream-hierarchy model, with results being best explained by historical river realignment or cross-catchment dispersal. The fact that both species show limited dispersal highlights the importance of conservation in highland areas for both endemic and widely spread species.

The geographic scale of speciation in a marine snail with high dispersal potential

2011 ◽  
Vol 38 (6) ◽  
pp. 1016-1032 ◽  
Author(s):  
Martine Claremont ◽  
Suzanne T. Williams ◽  
Timothy G. Barraclough ◽  
David G. Reid
Keyword(s):  
Geographic Scale ◽  
Marine Snail ◽  
High Dispersal ◽  
Dispersal Potential

scholarly journals Dispersal limitations of early life stages and sibling aggregations in a broadcastingMilleporahydrocoral, as revealed by parentage analysis

2018 ◽  
Author(s):  
Caroline E. Dubé ◽  
Emilie Boissin ◽  
Alexandre Mercière ◽  
Serge Planes
Keyword(s):  
Geographic Distance ◽  
French Polynesia ◽  
Parentage Analysis ◽  
Dispersal Ability ◽  
Dispersal Patterns ◽  
High Dispersal ◽  
Local Sustainability ◽  
Limited Dispersal ◽  
Dispersal Events ◽  
Critical Process

AbstractDispersal is a critical process for the persistence and productivity of marine populations. For many reef species, there is increasing evidence that local demography and self-recruitment have major consequences on their genetic diversity and adaptation to environmental change. Yet empirical data of dispersal patterns in reef-building species remain scarce. Here, we document the first genetic estimates of local dispersal and self-recruitment in a broadcasting reef-builder, the hydrocoralMillepora platyphylla. Using microsatellite markers, we gathered genotypic information from 3160 georeferenced colonies collected over 9000 m2of reef in three adjacent habitats in Moorea, French Polynesia; the mid slope, upper slope and back reef. Our parentage analysis revealed a predominance of self-recruitment with 58% of sexual propagules produced locally. Sexual propagules often settled at less than 10 meters from their parents and dispersal events decrease with increasing geographic distance. Limited dispersal among adjacent habitats via cross-reef transport was also detected. Sibship analysis showed that both full and half siblings recruit together on the reef, resulting in sibling aggregations. The identification of local families revealed discrepancies between dispersal patterns of sexual and asexual propagules. Self-recruits are dispersed with along-reef currents and settled in alignment with the location of their parents, while the dispersal of asexual fragments is heavily influenced by wave-driven cross-reef currents. Our findings highlight the importance of self-recruitment together with clonality in stabilising population dynamics, as it can enhance local sustainability and resilience to disturbance, but also raise uncertainties on the widely accepted high dispersal ability of broadcasting reef species.

scholarly journals Spatial analysis of plant species distribution among small water bodies in an agricultural landscape

2012 ◽  
Vol 61 (2) ◽  
pp. 93-101 ◽  
Author(s):  
Beata Bosiacka ◽  
Krzysztof Pacewicz ◽  
Paweł Pieńkowski
Keyword(s):  
Spatial Autocorrelation ◽  
Plant Species ◽  
Spatial Data ◽  
Agricultural Landscape ◽  
Water Bodies ◽  
Spatial Data Analysis ◽  
Small Water ◽  
Dispersal Potential ◽  
Limited Dispersal ◽  
Join Count Statistics

Due to their small size (0.02-1.0 ha), distinct boundaries, and conditions highly contrasting with those in the surrounding area, midfield water bodies are regarded as the so-called habitat islands. Their effective conservation calls for knowledge on their inhabitants' dispersal potential. However, direct empirical data are available for very few species only, but dispersal potential of a species may be inferred indirectly, from its distribution. The study addressed the question whether there is spatial autocorrelation in the distribution of plant species in midfield water bodies, or if the distribution is random. Spatial distribution of the midfield water bodies surveyed was analysed using the CrimeStat software, while spatial autocorrelation in distribution of 29 species was explored with the joincount.test routine of R CRAN software. Explorative spatial data analysis (ESDA) involving join-count statistics showed the presence of positive spatial autocorrelation in the distribution of ten hydro- and helophytic species. In their case, ESDA made it possible to reject the random distribution hypothesis, which opens up an avenue for exploring spatial patterns. Activities promoting the occurrence of species with limited dispersal potential should take into account their preferences in terms of shorter distances between neighbouring sites. This should make it possible to plan conservation of midfield water bodies not only as refuges, but also as stepping stone habitats facilitating migrations of wild species growing in an agricultural landscape.

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