stonewort

With regard to suitable plants for comparatively deep water in ponds or lakes, lakewort and stonewort grow on the bottom, and do not, as a rule, attain any considerable height.

Amateur Fish Culture Charles Edward Walker

It is important to note that there is evidence that, at least in Lake Krankesjön, these phenotypic changes occurred after colonization of the stonewort, since when isopods were initially sampled shortly after the stonewort started to expand (in 1987) they were phenotypically similar to reed individuals

PLoS ONE Alerts: New Articles Fabrice Eroukhmanoff et al. 2009

Selection for lower foraging activity and lower speed in turn might presumably result from the fact that isopods in the stonewort cannot escape from fish predators by swimming away, but have to rely on combinations of cryptic behavior, morphology and pigmentation to avoid predation.

PLoS ONE Alerts: New Articles Fabrice Eroukhmanoff et al. 2009

They are more stream-profiled and have higher escape speeds than isopods in the newly colonized stonewort habitat, which has higher density of fish predators.

PLoS ONE Alerts: New Articles Fabrice Eroukhmanoff et al. 2009

The latter mechanism may be selected for in the reed habitat, as reed isopods are faster at escaping and have higher endurance than stonewort isopods.

PLoS ONE Alerts: New Articles Fabrice Eroukhmanoff et al. 2009

These size classes were above or below .95 cm for the reed ecotypes, and above or bellow .75 cm for the stonewort ecotype.

PLoS ONE Alerts: New Articles Fabrice Eroukhmanoff et al. 2009

Predation from visually hunting fish is thus likely to be much more intense in the stonewort habitat than in the reed, due to higher densities of perch in the novel habitat

PLoS ONE Alerts: New Articles Fabrice Eroukhmanoff et al. 2009

In a recent study, we have showed that in these lakes, stonewort ecotype isopods were smaller in body size and had lighter body pigmentation

PLoS ONE Alerts: New Articles Fabrice Eroukhmanoff et al. 2009

Linear regression between endurance and speed for individuals from the reed and the stonewort.

PLoS ONE Alerts: New Articles Fabrice Eroukhmanoff et al. 2009

Indeed, although our data on exploratory behaviors comes from only one lake, and thus precludes generalization, we have also found in a previous study that stonewort individuals from both lakes had a lower propensity to engage mating, which also independently suggests a tendency to avoid exposure

PLoS ONE Alerts: New Articles Fabrice Eroukhmanoff et al. 2009