Slater Investigation on Responce to Light Stimuli
Erin Annabell
INTRODUCTION
The ecological niche of the Porcellio scaber: The Slater belongs to the biological class Crustacea. The slaters studied were found in damp, cool, humid conditions. They are most easily found in spring and autumn.
The most common site around the home is on compost heaps or under shelter such as bark, wood piles and boards left in shaded, moist conditions. They may also be found in deep, damp soil litter under the shelter of bushes or trees. So that they were not exposed to a lot of light and there is protection from predators such as blowflies and centipedes, sufficient food and damp. The ground was mostly made up of damp organic matter, damp soil, moist leaves, some were found on stony ground.
The light intensity is significant to the niche and way of life of the Slater because they are classed as scavengers; they live off decomposing matter and if the matter was in an open place they could get eaten by predators.
The Slaters found were in groups this was due to clumping of the slaters. Slaters are prone to desiccation, due to lack of a waterproof waxy cuticle. Slaters have many adaptations to help minimize and avoid desiccation.
Slaters prefer lower light intensities, this helps them keep hidden from predators and cool; not exposed to heat and not lose too much water, as they would do in greater light intensities
Slaters show orthokinesis, as light intensity increases and decreases from their preferred intensity. This means they are less likely to spend a lot of time in unfavourable conditions
Slaters show negative phototaxis so they move out of bright light.
Brighter light conditions are usually drier, so by staying out of the bright light slaters are minimizing desiccation
When slaters clump they are also less likely to loose too much water
High summer temperatures (up to 32 degrees C) cause the woodlice to retreat deeper into shelter making them more difficult to locate. The cooler winter temperatures (down to -5 degrees
INTRODUCTION
The ecological niche of the Porcellio scaber: The Slater belongs to the biological class Crustacea. The slaters studied were found in damp, cool, humid conditions. They are most easily found in spring and autumn.
The most common site around the home is on compost heaps or under shelter such as bark, wood piles and boards left in shaded, moist conditions. They may also be found in deep, damp soil litter under the shelter of bushes or trees. So that they were not exposed to a lot of light and there is protection from predators such as blowflies and centipedes, sufficient food and damp. The ground was mostly made up of damp organic matter, damp soil, moist leaves, some were found on stony ground.
The light intensity is significant to the niche and way of life of the Slater because they are classed as scavengers; they live off decomposing matter and if the matter was in an open place they could get eaten by predators.
The Slaters found were in groups this was due to clumping of the slaters. Slaters are prone to desiccation, due to lack of a waterproof waxy cuticle. Slaters have many adaptations to help minimize and avoid desiccation.
Slaters prefer lower light intensities, this helps them keep hidden from predators and cool; not exposed to heat and not lose too much water, as they would do in greater light intensities
Slaters show orthokinesis, as light intensity increases and decreases from their preferred intensity. This means they are less likely to spend a lot of time in unfavourable conditions
Slaters show negative phototaxis so they move out of bright light.
Brighter light conditions are usually drier, so by staying out of the bright light slaters are minimizing desiccation
When slaters clump they are also less likely to loose too much water
High summer temperatures (up to 32 degrees C) cause the woodlice to retreat deeper into shelter making them more difficult to locate. The cooler winter temperatures (down to -5 degrees
References: http://www.geocities.com/~gregmck/woodlice/habitat.htm Continuing Biology Bayley Meg, Layzell David. Pearsons Education NZ 2008 http://www.tki.org.nz/r/ncea/bio3_1A5_21feb09.doc