Phosphorus availability in the source population influences response to dietary phosphorus quantity in a New Zealand freshwater snail

Abstract

We investigated whether previously documented variation among populations in availability of dietary phosphorus (P) is linked to heterogeneity in growth rate of the New Zealand freshwater snail Potamopyrgus antipodarum on a P-limited diet. We chose this system because P. antipodarum inhabits water bodies that vary in P availability and because P. antipodarum growth rate varies considerably in response to low P. We quantified specific growth rate and alkaline phosphatase (AP) expression in a diverse array of juvenile P. antipodarum fed high vs. low-P diets. We found strong associations between P content of epilithon in the source lake and P. antipodarum growth rate on high vs. low-P diets, with snails collected from lakes with relatively low-P epilithon showing the greatest increase in growth rate on the high-P relative to low-P diet. We also found substantial intraspecific variation in growth response to P limitation. Expression of AP also varied among lineages and was negatively associated with C: P of lake epilithon but did not explain the relationship between C: P in the lake of origin and sensitivity to P limitation. Together, our results demonstrate a strong signature of the P environment in the lake of origin on how this snail responds to P limitation as well as preliminary evidence for intraspecific variation of AP expression in animals.

Eutrophication‐driven eco‐evolutionary dynamics indicated by differences in stoichiometric traits among populations of Daphnia pulicaria

“…Genotype × environment interactions in growth rate and fecundity revealed in our individual common garden experiment provided strong evidence for local adaptation among the genotypes studied. Interestingly, these results appear to contrast with those from similar studies with multiple species of Daphnia from lakes and ponds in Michigan (DeMott & Pape, 2005) and multiple populations of the snail Potamopyrgus antipodarum in New Zealand (Krist et al, 2017). The former found no clear relationship between source habitat stoichiometry and growth response to a P-enriched diet (DeMott & Pape, 2005), while the latter found the opposite result to ours in that populations from lakes with low P exhibited the greatest growth response on a P-enriched diet (Krist et al, 2017).…”

Invasive freshwater snails form novel microbial relationships

“…All metacercariae were removed from infected snails using a micropipette. After dissection, we used flow cytometry (Krist et al, 2017;Neiman et al, 2011)…”

Asexuality Associated with Marked Genomic Expansion of Tandemly Repeated rRNA and Histone Genes

“…This hypothesis predicts that rapidly growing consumer organisms that are growth limited by dietary P-availability might be particularly affected by changes in rDNA abundance. Growth rate in P. antipodarum is sharply reduced under dietary phosphorus limitation ( Tibbets et al 2010 ; Neiman et al 2013 ; Krist et al 2014 ; Neiman and Krist 2016 ), and asexual P. antipodarum demonstrate extensive genetic and population-level variation in response to P limitation ( Krist et al 2014 ; Krist et al 2017 ). The naturally occurring wide range of rDNA abundance we observe here coupled with the strong link of P availability to P. antipodarum growth presents a compelling setting to directly test predictions from the growth-rate hypothesis.…”