The rise in popularity of isopods

In recent times isopods have grown in popularity in the invertebrate hobby. Isopods make interesting and amazing pets for the invertebrate hobby and also serve an important role in any bioactive ecosystem. Isopods rarely destroy living plants, preferring to eat decaying vegetation including decaying leaf litter and rotten wood. Isopods break down the decaying material into smaller fragments and then deposit it back into the ground as faecal pellets. This process promotes rapid decomposition by bacteria and fungi, returning the good nutrients back into the soil and supports new vegetation growth. It’s not unsurprising to see why isopods have grown in popularity.

The most common species of isopods that are easily found across England in the wild and within the isopod hobby are:

Armadillidium vulgare (the common pill woodlouse)

This is a generalist species, found in nature and man-made sites. Extremely common in England especially in the South and East England but appears to be absent from central Northern England.

Armadillidium vulgare have the following key characteristics:-

• Length: 18mm.

• Colour: Uniform slate grey, pink or brown. Mottled patterns can be found around coastal areas.

• Number of pleopodal lungs: Two.

• Flagella: Two segments.

• Behaviour: Rolls into a perfect sphere when disturbed.

Oniscus asellus (the common shiny woodlouse)

Found in all damp habitats, especially common under bark and rotting wood in woodlands. Extremely common across the British Isles.

Oniscus asellus have the following key characteristics:-

How to identify:

• Length: 16mm.

• Colour: Very shiny and grey with two rows of yellow patches along the outside of the pereon.

• Number of pleopodal lungs: None.

• Flagella: Three segments.

• Behaviour: Initially remains motionless when disturbed, runs quickly when continuously provoked. May be difficult to pick up due to its flattened body and smooth surface. Does not roll up into a ball.

Porcellio scaber (the common rough woodlouse)

They are found in a variety of habitats throughout Britain and Ireland. It prefers drier conditions compared to other common species (such as Oniscus asellus), so is often found within compost heaps.

Porcellio scaber have the following key characteristics:-

How to identify:

• Length: 17mm.

• Colour: Slate grey, with a dull, rough look to the exoskeleton.

• Number of pleopodal lungs: two pairs.

• Flagella: Two segments.

• Behaviour: Initially remains motionless but runs away quickly when disturbed. Does not roll into a ball.

Philoscia muscorum (the common striped woodlouse)

They can be found in hedgerows and grasslands. This woodlouse is often hidden at the base of grass tussocks. Common through Britain and Ireland.

Philoscia muscorum have the following key characteristics:-

How to identify:

• Length: 11mm.

• Colour: Shiny mottled brown with a dark central stripe.

• Number of pleopodal lungs: None.

• Flagella: Three segments.

• Behaviour: Runs extremely fast when disturbed and feels soft to the touch when attempted to be picked up.

Trichoniscus pusillus (the common pygmy woodlouse)

They can be found in damp soil and damp leaf litter. It is very common and found throughout the British Isles.

Trichoniscus pusillus have the following key characteristics:-

How to identify:

• Length: 5mm.

• Colour: Purplish-brown or reddish-brown.

• Number of pleopodal lungs: None.

• Flagella: One distinct conical section that tapers to a point.

• Behaviour: Runs rapidly when disturbed.