Ph Effect Slaters

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Armadillium vulgare taxis response to different pH levels.


The terrestrial isopod, Armadillium vulgare is commonly referred to as a slater or pill bug. Since transitioning from the sea to land and originally colonizing in Mediterranean regions, it has adapted throughout evolution to inhabit local microhabitats. The pill bug is bound by several parameters and also has specific requirements that need to be met for optimal biological functioning. As such, behavioural and physiological responses of the pill pub are altered in response to distinctive conditions in its environment. The experiment was conducted utelising the variable of pH in order to determine taxis response of the pill bug. The experiment was conducted in a container, which was divided in half with a pH substrate side tested against a control side. The movements and actions of the test slaters were recorded at constant time intervals. The results observed illustrate the preference of a basic NaOH in comparison to the acidic HCI solution. The explanation of this result can be referred against previous studies, which illustrate mechanisms such as conglobation and thigmokinesis employed by slaters in order to create a stable environment whilst in unfavourable conditions.


Terrestrial Isopods make up over 1000 different species (water). Armadillium vulgare belong to the order of isopod, however it is more commonly known as a rollie poly, pill bug or slater (azza). Of the vast ranging crustacean subphylum, Isopoda are the only order to have successfully transitioned from aquatic life to terrestrial habitats (intra) and have colonized on land (water). A. vulgare originated around Mediterranean regions (water pg7). Despite this, they now have much diversity and range throughout continuing regions on the world. This has been achieved by formation of close microhabitat selections and local adaptions (water). Investigations on population dynamics of the A. vulgare have been undertaken in order to determine estimated parameters for continuing success of their evolution (intra). Slaters seek shelter in their habitat (water) as well as seeking moisture from fallen trees and rotting wood (water). A. vulgare is a detritivore, primarily acting as a reducer organism (intra). Pill bugs are considered a problematic pest in some regions worldwide causing economic loss for producers of fresh produce (lettuce). Most notable affects can be witnessed in Mexico, who remains the eighth largest lettuce producer in the world (lettuce).

Slaters have a large diversity worldwide however; they are poorly physiologically adapted for living on land (water). As a consequence, pill bugs behaviour and physiological responses is a reflection of their main initiative, to keep water loss to a minimum in order to assist to promote normal biological functioning. pH is one important physiological parameter that A. vulgare is bound by. It can heavily influence the characteristics its behaviour (pH). Studies have been previously conducted to observe the efficiency of using pH as a pesticide and deterrent. Some reports have also shown the use of A. vulgare as a biological marker for pH soil detection levels by the monitoring of A. vulgare movement. The main objective of the experiment was to observe the taxis of A. vulgare and their associated behavioural response to different pH levels to determine preferred environmental condition.

Materials and methods

Prior to the experiment commencing, the A. vulgare had been contained in a clear storage container that was filled with matter consisting of a clay soil and shrubbery from its natural habitat. There were two types of Isopods present for selection from the mix. These consisted of slaters that were capable of conglobation and also isopods that had a cephalothorax. Conglobation is the action of the slaters rolling up into an uninterrupted spherical position. The cephalothorax is the anatomical segment,...
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