Limits...
Phenotypic variation and fitness in a metapopulation of tubeworms (Ridgeia piscesae Jones) at hydrothermal vents.

Tunnicliffe V, St Germain C, Hilário A - PLoS ONE (2014)

Bottom Line: This foundation species at northeast Pacific hydrothermal sites occupies a wide habitat range in a highly heterogeneous environment.Although only the largest worms were measured, only 17% of low flux worms were reproductively competent compared to 91% of high flux worms.This foundation species forms a metapopulation with variable growth characteristics in a heterogeneous environment where a strategy of phenotypic variation bestows an advantage over specialization.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, University of Victoria, Victoria, British Columbia, Canada; School of Earth & Ocean Sciences, University of Victoria, Victoria, British Columbia, Canada.

ABSTRACT
We examine the nature of variation in a hot vent tubeworm, Ridgeia piscesae, to determine how phenotypes are maintained and how reproductive potential is dictated by habitat. This foundation species at northeast Pacific hydrothermal sites occupies a wide habitat range in a highly heterogeneous environment. Where fluids supply high levels of dissolved sulphide for symbionts, the worm grows rapidly in a "short-fat" phenotype characterized by lush gill plumes; when plumes are healthy, sperm package capture is higher. This form can mature within months and has a high fecundity with continuous gamete output and a lifespan of about three years in unstable conditions. Other phenotypes occupy low fluid flux habitats that are more stable and individuals grow very slowly; however, they have low reproductive readiness that is hampered further by small, predator cropped branchiae, thus reducing fertilization and metabolite uptake. Although only the largest worms were measured, only 17% of low flux worms were reproductively competent compared to 91% of high flux worms. A model of reproductive readiness illustrates that tube diameter is a good predictor of reproductive output and that few low flux worms reached critical reproductive size. We postulate that most of the propagules for the vent fields originate from the larger tubeworms that live in small, unstable habitat patches. The large expanses of worms in more stable low flux habitat sustain a small, but long-term, reproductive output. Phenotypic variation is an adaptation that fosters both morphological and physiological responses to differences in chemical milieu and predator pressure. This foundation species forms a metapopulation with variable growth characteristics in a heterogeneous environment where a strategy of phenotypic variation bestows an advantage over specialization.

Show MeSH

Related in: MedlinePlus

Locations of sampling sites on Juan de Fuca Ridge.Endeavour inset shows the three sampled vent fields: Clam Bed, Main Endeavour and Mothra. Axial inset shows locations of samples from three fields and the grey line near SRZ (arrow) delineates the extent of the 1998 lava flow.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4206443&req=5

pone-0110578-g001: Locations of sampling sites on Juan de Fuca Ridge.Endeavour inset shows the three sampled vent fields: Clam Bed, Main Endeavour and Mothra. Axial inset shows locations of samples from three fields and the grey line near SRZ (arrow) delineates the extent of the 1998 lava flow.

Mentions: The hydrothermal vents on Juan de Fuca Ridge (Figure 1) are located at discrete sites on separate segments of the ridge. Axial Volcano is one such site where vents within the caldera at ∼1550 m depth are short-lived due to lava eruptions. On Endeavour Segment, venting in the axial spreading valley is concentrated in several “vent fields” where fluids emerge through mineralized chimneys and through cracked seafloor basalts. Extrusive volcanism has not occurred within observation history here. Fields, separated by about 2 km, have multiple black smoker chimneys, clusters of animals around vent openings, and scattered tubeworms in low density. Collections came from Clam Bed, Main Field and Mothra Field at ∼2200 m depth (Figure 1). Deep-sea access was provided by the remotely operated vehicle ROPOS and the occupied vehicle Alvin, both of which used advanced force feed-back manipulators for collecting samples. Collection permits for this work were issued by Fisheries and Oceans Canada.


Phenotypic variation and fitness in a metapopulation of tubeworms (Ridgeia piscesae Jones) at hydrothermal vents.

Tunnicliffe V, St Germain C, Hilário A - PLoS ONE (2014)

Locations of sampling sites on Juan de Fuca Ridge.Endeavour inset shows the three sampled vent fields: Clam Bed, Main Endeavour and Mothra. Axial inset shows locations of samples from three fields and the grey line near SRZ (arrow) delineates the extent of the 1998 lava flow.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4206443&req=5

pone-0110578-g001: Locations of sampling sites on Juan de Fuca Ridge.Endeavour inset shows the three sampled vent fields: Clam Bed, Main Endeavour and Mothra. Axial inset shows locations of samples from three fields and the grey line near SRZ (arrow) delineates the extent of the 1998 lava flow.
Mentions: The hydrothermal vents on Juan de Fuca Ridge (Figure 1) are located at discrete sites on separate segments of the ridge. Axial Volcano is one such site where vents within the caldera at ∼1550 m depth are short-lived due to lava eruptions. On Endeavour Segment, venting in the axial spreading valley is concentrated in several “vent fields” where fluids emerge through mineralized chimneys and through cracked seafloor basalts. Extrusive volcanism has not occurred within observation history here. Fields, separated by about 2 km, have multiple black smoker chimneys, clusters of animals around vent openings, and scattered tubeworms in low density. Collections came from Clam Bed, Main Field and Mothra Field at ∼2200 m depth (Figure 1). Deep-sea access was provided by the remotely operated vehicle ROPOS and the occupied vehicle Alvin, both of which used advanced force feed-back manipulators for collecting samples. Collection permits for this work were issued by Fisheries and Oceans Canada.

Bottom Line: This foundation species at northeast Pacific hydrothermal sites occupies a wide habitat range in a highly heterogeneous environment.Although only the largest worms were measured, only 17% of low flux worms were reproductively competent compared to 91% of high flux worms.This foundation species forms a metapopulation with variable growth characteristics in a heterogeneous environment where a strategy of phenotypic variation bestows an advantage over specialization.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, University of Victoria, Victoria, British Columbia, Canada; School of Earth & Ocean Sciences, University of Victoria, Victoria, British Columbia, Canada.

ABSTRACT
We examine the nature of variation in a hot vent tubeworm, Ridgeia piscesae, to determine how phenotypes are maintained and how reproductive potential is dictated by habitat. This foundation species at northeast Pacific hydrothermal sites occupies a wide habitat range in a highly heterogeneous environment. Where fluids supply high levels of dissolved sulphide for symbionts, the worm grows rapidly in a "short-fat" phenotype characterized by lush gill plumes; when plumes are healthy, sperm package capture is higher. This form can mature within months and has a high fecundity with continuous gamete output and a lifespan of about three years in unstable conditions. Other phenotypes occupy low fluid flux habitats that are more stable and individuals grow very slowly; however, they have low reproductive readiness that is hampered further by small, predator cropped branchiae, thus reducing fertilization and metabolite uptake. Although only the largest worms were measured, only 17% of low flux worms were reproductively competent compared to 91% of high flux worms. A model of reproductive readiness illustrates that tube diameter is a good predictor of reproductive output and that few low flux worms reached critical reproductive size. We postulate that most of the propagules for the vent fields originate from the larger tubeworms that live in small, unstable habitat patches. The large expanses of worms in more stable low flux habitat sustain a small, but long-term, reproductive output. Phenotypic variation is an adaptation that fosters both morphological and physiological responses to differences in chemical milieu and predator pressure. This foundation species forms a metapopulation with variable growth characteristics in a heterogeneous environment where a strategy of phenotypic variation bestows an advantage over specialization.

Show MeSH
Related in: MedlinePlus