Nine‐spined stickleback (Pungitius pungitius): an emerging model for evolutionary biology research

Abstract

The nine-spined stickleback (Pungitius pungitius) is emerging as a model for evolutionary biology, genetic, and behavioral research in the wake of its better-known relative, the three-spined stickleback (Gasterosteus aculeatus). This interest has been fed by its fascinating biological features, such as the repeated evolution of similar phenotypes in isolated pond populations. A large body of recent research has uncovered the finding that pond nine-spined sticklebacks have evolved numerous morphological, life history, neuroanatomical, and behavioral adaptations-possibly in response to reduced threat of fish predation-which differentiate them from their marine conspecifics. These features, together with insights from recent population genetic studies, suggest that this species provides an interesting model for studies aiming to understand-and differentiate between-genetic convergence and parallelism as underlying mechanism(s) of evolution of similar phenotypes in multiple independent sites. This review provides a synopsis of and reflections on the insights borne out of recent studies of nine-spined sticklebacks-the little sister of ecology's "new supermodel."

Lakes and ponds as model systems to study parallel evolution

“…In fact, empirical studies to this effect are still rare in any organisms (van Treuren et al, 1993;Paland and Schmid, 2003;Willi et al, 2005;Escobar et al, 2008;Coutellec and Caquet, 2011;Willi et al, 2013). This in spite of the fact that the issue is important not least in the view that populations remaining small and isolated for extensive time periods, such as the post glacially isolated pond populations of nine-spined sticklebacks in Fennoscandia (Merilä, 2013), are likely to accumulate substantial drift load with negative effects on mean population fitness. If so, their ability to adapt to environmental changes such as climate warming may be seriously constrained not only by low levels of genetic variability, but also by drift load (Hoffmann and Willi, 2008).…”

“…For instance, in spite of severely reduced genetic variability in isolated pond populations of nine-spined sticklebacks in Fennoscandia (Shikano et al, 2010), these populations show evidence for a high degree of parallel evolution in multiple phenotypic traits, apparently in response to lack of predation (reviewed in Merilä, 2013). Likewise, mosquitofish (Gambusia hubbsii) populations subject to strong genetic drift and low genetic variability (Shugg et al, 1998) show parallel adaptation in response predator mediated selection (Langerhans et al, 2007).…”

Platichthys solemdali sp. nov. (Actinopterygii, Pleuronectiformes): A New Flounder Species From the Baltic Sea

“…It has also been speculated that bony plates may provide a defense against predation (Spinner et al, 2016), as in three-spined Gasterosteus aculeatus (Barrett, 2010) and nine-spined Pungitius pungitius (Merilä, 2013) sticklebacks. Baltic flounders show high variability in terms of numbers of bony plates, exhibiting phenotypes 1-4 described by Voronina (1999).…”

The developmental transcriptome of contrasting Arctic charr (Salvelinus alpinus) morphs

“…Some northern freshwater fish species exhibit frequent parallelism in trophic structures and life history and in several cases are they found as distinct resource morphs 8, 21– 25 . One of these species, Arctic charr ( Salvelinus alpinus ), is well suited for studying the developmental underpinnings of trophic divergence and parallel evolution.…”