Year 13 Animal Study

Porcellio scaber

Most slaters are a mottled gray colour. This gives them good camouflage in their chosen habitat. Occasionally you will find orangeorange, purplepurple and whitewhite slaters. The never appear to be many of these of these other colours. Probably they are selected against by predators who find them easier to find and eat.

Porcellio scaber

Superkingdom: EukaryotaEukaryotaKingdom: MetazoaMetazoaPhylum: ArthropodaArthropoda Subphylum: CrustaceaCrustaceaClass: MalacostracaMalacostracaSubclass: EumalacostracaEumalacostracaSuperorder: PeracaridaPeracaridaOrder: IsopodaIsopodaSuborder: OniscideaOniscideaFamily: PorcellionidaePorcellionidaeGenus: PorcellioPorcellioSpecies: scaberscaber

Superkingdom: Eukaryota Eukaryota Kingdom: MetazoaMetazoaPhylum: ArthropodaArthropoda Subphylum: CrustaceaCrustaceaClass: MalacostracaMalacostracaSubclass: EumalacostracaEumalacostracaSuperorder: PeracaridaPeracaridaOrder: IsopodaIsopodaSuborder: OniscideaOniscideaFamily: ArmadillidiidaeArmadillidiidaeGenus: ArmadillidiumArmadillidiumSpecies: vulgarevulgare

Slaters moult one half of the body at a time.

New born slaters

The female places the fertilized eggs into a brood pouch under her abdomen. When fully developed the young slaters just crawl out of the brood pouch. They are born with 6 pairs of walking legs (periopods)

What is the reason that What is the reason that Porcellio scaberPorcellio scaber excrete excrete ammonia?ammonia?

Why does this occur? Why does this occur?

Woodlice do not produce Woodlice do not produce urine. Instead of excreting urine. Instead of excreting urine, woodlice excrete their urine, woodlice excrete their nitrogenous waste in the form nitrogenous waste in the form of of ammonia gasammonia gas..

Most animals find ammonia to Most animals find ammonia to be too toxic for excretion and be too toxic for excretion and so any ammonia formed is so any ammonia formed is normally converted to urea or normally converted to urea or uric acid for excretion.uric acid for excretion.

Woodlice seem to have very Woodlice seem to have very high resistance to ammonia high resistance to ammonia and are able to excrete it as a and are able to excrete it as a gas directly through the gas directly through the surface of their exoskeleton. surface of their exoskeleton. This means that they do not This means that they do not need to use energy to convert need to use energy to convert the ammonia to urea or uric the ammonia to urea or uric acid before acid before excretion.excretion.

Pseudotrachae are found on pleopods one and two of both males and females. They have a single opening to the outside. Inside the pleopod they branch out into an array of fine tubes. In this way they increase the area for gas exchange.