Role of dispersal ability in the phenotypic differentiation and plasticity of two marine gastropods

Abstract

Species with contrasting abilities for dispersal may adopt different strategies in response to wide ranges of environmental conditions. These strategies were investigated here by comparisons of phenotypic differentiation and plasticity in the gastropods Austrocochlea constricta and Bembicium vittatum, which coexist in a range of intertidal habitats on the Abrolhos Islands and Albany in Western Australia. They differ in their potential for larval dispersal, A. constricta having a short mobile planktonic stage and B. vittatum developing directly from benthic eggs. Levels of among-population variation in shell shape and maximum size did not differ between the species, or between locations subject to contrasting levels of gene flow in the case of A. constricta. Results of a common garden translocation experiment, coupled with those of previous breeding experiments, suggest that variation in shape is predominantly genetically determined in B. vittatum, but plastic in A. constricta. Plasticity of shape in A. constricta was most pronounced at Albany, where previous data suggested the widest gene flow, and was greater than in B. vittatum at both locations. Change of shape in A. constricta subsequent to translocation was related to growth rate, a trait which was also more plastic in this species than in B. vittatum. The results agree with the notion that wide dispersal enhances physiological flexibility, while restricted dispersal promotes local genetic adaptation, but disagree with the hypothesis that wide dispersal promotes phenotypic homogeneity.

Intertidal oysters reach their physiological limit in a future high-CO2 world

“…Here, it was found that any acclimation to a high-intertidal environment is likely to be due to a plastic acclimatory response, rather than adaption. In broadcast spawning organisms such as oysters, larval dispersal decreases the capacity to adapt to local conditions and increases the prevalence of phenotypic plasticity (Parsons, 1997;Kinlan and Gaines, 2003).…”

What can aquatic gastropods tell us about phenotypic plasticity? A review and meta-analysis

“…Further, marine species with benthic development may disperse widely via rafting on seaweeds (Highsmith, 1985;Martel and Chia, 1991;Donald et al, 2011). It is becoming increasingly clear that direct developing species with low dispersal capacity can display strong plastic responses, whereas planktonic developers with high dispersal capacity may exhibit little or no plasticity (Behrens Yamada, 1989;Parsons, 1997;Hollander et al, 2006). Our meta-analyses support these findings and suggest that larval dispersal may not have a large role in creating the environmental heterogeneity marine gastropods experience once they settle, nor in selecting for plasticity.…”

Mitochondrial genomes and divergence times of crocodile newts: Inter-islands distribution of <i>Echinotriton andersoni</i> and the origin of a unique repetitive sequence found in <i>Tylototriton</i> mt genomes

“…The difference in the lineage split modes between the newts and the frogs may be attributable to the low dispersal ability known in newts (e.g., Joly et al, 2001). Because dispersal ability determines the potential for gene flow between local populations (e.g., Parsons, 1997), the low dispersal capacity in newts would easily lead to a reduction of gene flow among the populations in Cynops and Echinotriton and might cause lineage splits among these populations without obvious geographic barriers like island formation.…”