Advances in the molecular analysis of fish population structure

Abstract

The characteristics of high population and species biodiversity, taken together with the major anthropogenic threats arising from exploitation, introductions and habitat alterations, have ensured that fishes have received major attention from molecular biologists in the study of wild populations. Foremost among the various challenges has been the development of techniques to estimate population discreteness and associated patterns of dispersal and gene flow, so-called stock structure analysis. Here, we review some recent developments in molecular technology, especially microsatellite analysis, and consider critically how such markers can be employed to estimate genetic differentiation in species exhibiting high mobility in open waters. Comparisons are made between microsatellites and other genetic markers (protein and DNA) in their ability to detect population structuring. Particular emphasis is placed on the need to design sampling programmes that take account of aspects of the biology of the species under study, and the scale and nature of sample collection. Recent novel applications of PCR-based technology in the analysis of population structure are considered, including the detection of microgeographic differentiation, the analysis of historical fish populations using recovered DNA, and the molecular characterization of allelic variants among populations in relation to function.

Microsatellite DNA variation reveals high gene flow and panmictic populations in the Adriatic shared stocks of the European squid and cuttlefish (Cephalopoda)

“…Genetic variability in the Adriatic cephalopod stocks Polymorphic microsatellite loci are useful genetic markers for indirect monitoring of demographic features of marine fishery resources (Carvalho and Hauser, 1998). In contrast to allozymes, species-specific microsatellites allow more powerful and accurate tests of population genetic parameters in cephalopods Reichow and Smith, 2001;Pérez-Losada et al, 2002).…”

“…The perception that natural resources are not inexhaustible, the collapse of internationally relevant fisheries stocks and the estimate that 60% of the major marine fisheries are either fully exploited or overexploited (FAO, 1997), promoted a great number of scientific investigations to solve bio-ecological and demographic questions in a huge number of marine populations (Carvalho and Hauser, 1998). The assessment of spatial and temporal patterns of genetic diversity and related demographic features (eg number of migrants, geographical boundaries of populations) may be useful for the conservation and sustainable management of marine resources.…”

Historical Processes and Contemporary Anthropogenic Activities Influence Genetic Population Dynamics of Nassau Grouper (Epinephelus striatus) within The Bahamas

“…Advances in molecular biology and population genetics have proven to be extremely valuable in generating information on population status, genetic diversity and connectivity of a variety of fish species (Carvalho and Hauser, 1998;SilvaOliveira et al, 2008;Davey et al, 2011;Adams et al, 2016;Garcia-Mayoral et al, 2016); in turn, these data have been applied to support population management and conservation efforts Beldade et al, 2014;Selkoe et al, 2016). In particular, the application of genetics for stock identification (Carvalho and Hauser, 1994) and estimates of effective population size, N e (Wright, 1931), combined with traditional fisheries stock assessment models (Hilborn and Walters, 1992) are emerging approaches for advancing conservation management of at-risk species (Luikart et al, 2010;Hare et al, 2011;Ovenden et al, 2016).…”

Marked genetic structuring in localised spawning populations of cod Gadus morhua in the North Sea and adjoining waters, as revealed by microsatellites

“…The recent development of significantly more sensitive molecular genetic markers has stimulated renewed interest in the analysis of population structure in marine fishes (O'Connell & Wright 1997, Carvalho & Hauser 1998, which have hitherto been characterised by lower genetic diversity and differentiation when compared with anadromous and freshwater species (Ward et al 1994). Such differences have been related to a presumed lack of isolating barriers, large population sizes and high mobility (Smith 1994, Carvalho &often approaching 90% (O'Connell & Wright 1997, Ruzzante 1998.…”