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. From Wordnik.com. [Amateur Fish Culture] Reference
The isopods colonized the stonewort from a source habitat consisting of reed. From Wordnik.com. [PLoS ONE Alerts: New Articles] Reference
Linear regression between endurance and speed for individuals from the reed and the stonewort. From Wordnik.com. [PLoS ONE Alerts: New Articles] Reference
These size classes were above or below .95 cm for the reed ecotypes, and above or bellow .75 cm for the stonewort ecotype. From Wordnik.com. [PLoS ONE Alerts: New Articles] Reference
Thus, the reed isopods perform better overall than the stonewort isopods, and are able to have both high speed and high endurance. From Wordnik.com. [PLoS ONE Alerts: New Articles] Reference
This ecological difference between the two habitats has been suggested to select for smaller, brighter isopods in the stonewort habitat. From Wordnik.com. [PLoS ONE Alerts: New Articles] Reference
In a recent study, we have showed that in these lakes, stonewort ecotype isopods were smaller in body size and had lighter body pigmentation. From Wordnik.com. [PLoS ONE Alerts: New Articles] Reference
Here we have shown that the stonewort isopods have a broader anterior head angle (Fig. 5) and a thinner tail than isopods in the reed habitat. From Wordnik.com. [PLoS ONE Alerts: New Articles] Reference
At equal speeds, the ratio between the forces of drag sustained by the reed individuals and the stonewort individuals is estimated to be 0.8522. From Wordnik.com. [PLoS ONE Alerts: New Articles] Reference
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. From Wordnik.com. [PLoS ONE Alerts: New Articles] Reference
As a consequence, at equal speeds, the ratio between the forces of drag sustained by the reed individuals and the stonewort individuals is equal to 0.8522. From Wordnik.com. [PLoS ONE Alerts: New Articles] Reference
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. From Wordnik.com. [PLoS ONE Alerts: New Articles] Reference
Using the inverse of this ratio, we can estimate the extra amount of force (in%) that would be needed by an average stonewort isopod to swim at the same speed as an average reed isopod. From Wordnik.com. [PLoS ONE Alerts: New Articles] Reference
Since overall prey crypsis is likely be a result of both pigmentation and morphological traits such as size and shape, it might be an adaptive response to the visually hunting fish predators in the stonewort habitat. From Wordnik.com. [PLoS ONE Alerts: New Articles] Reference
Consequently, predator-mediated selection from fish in the stonewort habitat may have selected for novel trait combinations involving brighter pigmentation, prudent behaviors and lower speed to avoid the attention of predators. From Wordnik.com. [PLoS ONE Alerts: New Articles] Reference
A simple biomechanical model has thus its limitations here, since to be able to swim at the same speed, the average stonewort isopod would have to produce a propulsion force 17. 3% higher than the reed isopods if one considers drag as the only factor affecting speed. From Wordnik.com. [PLoS ONE Alerts: New Articles] Reference
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. From Wordnik.com. [PLoS ONE Alerts: New Articles] Reference
By disrupting the ancestral modular structure and increasing the overall level of phenotypic integration, predator-mediated selection might have resulted in a hydrodynamically less favorable shape in the stonewort habitat as a correlated response to selection for higher phenotypic integration. From Wordnik.com. [PLoS ONE Alerts: New Articles] Reference
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. From Wordnik.com. [PLoS ONE Alerts: New Articles] Reference
In both Lake Tåkern and Lake Krankesjön, as in five other lakes, habitat-specific changes in pigmentation were observed following colonization: isopods became brighter in the stonewort stands compared to the darker ancestral populations in the reed, and these pigmentation differences are largely heritable. From Wordnik.com. [PLoS ONE Alerts: New Articles] Reference
stonewort species include bird’s nest stonewort Tolypella nidifica, a species that thrives in brackish water, and coral stonewort Chara tomentosa. From Wordnik.com. [Kvarken Archipelago High Coast, Finland and Sweden] Reference
"sit-and-wait" - predators that rely primarily on tactile cues (i.e. dragonfly and damselfly larvae) are the main threat towards the isopods In spring 2007, a total of 20 males from each ecotype (reed and stonewort) and each lake (Lake Tåkern and Lake Krankesjön) were collected in the field (N = 80 males in total). From Wordnik.com. [PLoS ONE Alerts: New Articles] Reference
During the past two decades, a recently emerged habitat (stonewort. From Wordnik.com. [PLoS ONE Alerts: New Articles] Reference
Fig. 3), as the reed isopods are both faster and have higher endurance than the stonewort isopods (. From Wordnik.com. [PLoS ONE Alerts: New Articles] Reference
Perca fluviatilis), whose populations grew in a correlated fashion with the expansion of the stonewort. From Wordnik.com. [PLoS ONE Alerts: New Articles] Reference
In contrast, there was no evidence of any modular structure at all in the two populations of the stonewort ecotype from the two lakes (. From Wordnik.com. [PLoS ONE Alerts: New Articles] Reference
Perca fluviatilis) are common, but invertebrate predators are almost entirely absent Types of potential predators present in the source reed ecotypes and in the new stonewort ecotypes. From Wordnik.com. [PLoS ONE Alerts: New Articles] Reference
All traits in the stonewort populations were deeply connected to each other, resulting in an increased overall degree of phenotypic integration of all the traits, compared to the situation in the ancestral reed ecotype in both lakes (. From Wordnik.com. [PLoS ONE Alerts: New Articles] Reference
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