Biology Investigation: Woodlice
* Biology Investigation 3.1
Porcellio Scaber (Slater, Woodlouse)
Task 1
The crustacean Porcellio Scaber, or more commonly known as the woodlouse, is a species usually found in leaf litter or in fallen trees and bark. It feeds on detritus like many other isopods of its type, and is generally predated on by small mammals, lizards and some insects. The woodlouse habitat reflects its need to avoid warm and dry areas. The woodlouse is prone to desiccation (drying out) due to its body’s large surface area to volume ratio. This results in a variety of behavioural adaptations that help it conserve moisture and avoid desiccation.
The woodlouse exhibits negative phototaxes behaviour, this results in them moving away from brighter areas in order to find a darker one. This is because darker areas are usually damper and will be better for moisture conservation. In terms of humidity they show a kinetic reaction to dry conditions. Their rate of movement will increase in dry areas along with their rate of turning in order to quickly find a damper area. They will also move slower in humid conditions in order to conserve energy. They show a similar response in regards to an increase in temperature. A warmer environment promotes desiccation, while a cooler environment will help conserve moisture.
Other responses shown include a positive thigmokinetic behavioural reaction. A woodlouse’s rate of movement will decrease in regards to how much of its body is in contact with another object. This results in a ‘clumping’ behaviour with groups of woodlice. They will group together in order to stave off both desiccation and risk of predation.
As well as behavioural adaptations the woodlouse also has several physiological adaptations that increase its chances of survival and subsequently reproduction. Its respiration system consists of a pore on the outside of its body that lets air in to a pseudo-lung that will absorb oxygen directly from the air. This pore is permanently open
Porcellio Scaber (Slater, Woodlouse)
Task 1
The crustacean Porcellio Scaber, or more commonly known as the woodlouse, is a species usually found in leaf litter or in fallen trees and bark. It feeds on detritus like many other isopods of its type, and is generally predated on by small mammals, lizards and some insects. The woodlouse habitat reflects its need to avoid warm and dry areas. The woodlouse is prone to desiccation (drying out) due to its body’s large surface area to volume ratio. This results in a variety of behavioural adaptations that help it conserve moisture and avoid desiccation.
The woodlouse exhibits negative phototaxes behaviour, this results in them moving away from brighter areas in order to find a darker one. This is because darker areas are usually damper and will be better for moisture conservation. In terms of humidity they show a kinetic reaction to dry conditions. Their rate of movement will increase in dry areas along with their rate of turning in order to quickly find a damper area. They will also move slower in humid conditions in order to conserve energy. They show a similar response in regards to an increase in temperature. A warmer environment promotes desiccation, while a cooler environment will help conserve moisture.
Other responses shown include a positive thigmokinetic behavioural reaction. A woodlouse’s rate of movement will decrease in regards to how much of its body is in contact with another object. This results in a ‘clumping’ behaviour with groups of woodlice. They will group together in order to stave off both desiccation and risk of predation.
As well as behavioural adaptations the woodlouse also has several physiological adaptations that increase its chances of survival and subsequently reproduction. Its respiration system consists of a pore on the outside of its body that lets air in to a pseudo-lung that will absorb oxygen directly from the air. This pore is permanently open
References: http://www.issg.org/database/species/ecology.asp?si=1460&fr=1&sts=&lang=EN http://www.porcellio.scaber.org/woodlice/habitat.htm http://www.porcellio.scaber.org/woodlice/wliceod.htm