Armadillidium nasatum

picture by Liliana Sanfilippo

English	German	Name
Order	Ordnung	Isopoda
Suborder	Unterordnung	Oniscidea
Family	Familie	Armadillidiidae
Genus	Gattung	Armadillidium
Species	Art	Armadillidium nasatum

Description

Like all Armadillidium, they can roll into a ball though they leave a little gap open and their antenna outside. They are usually 10-15 mm big but can grow up to 21 mm.

They have a little “nose” or “snout” on their face, hence the name, and usually pale stripes as seen in the picture.

In nature, they come in three different colour variations that are orange/red, black/grey and brown. “Red” is what is called “peach” in the hobby. Through breeding, a lot of nuances can be shown and they can also be very pale up to white. It is also possible that there are multiple colours present in one individual.

Habitat

Like other isopods, they hide a lot under stones and wood. They like warmth and rough-grained stony soil.

Distribution

Originally, they were mostly found in (southern) Europe but as of today they can be found in all of Europe, in North, Middle and South America, Central Asia and they have been observed in Japan and Korea. North from England they are rarely found.

Care

They can easily live in room temperature and are not super sensitive about humidity or rather a lack thereof. 50 % moisture is deemed good enough.

General care tips apply such as having a moisture gradient and lots of hiding spaces.

They do not need a special diet.

First description

Budde-Lund, G. (1885). Crustacea Isopoda Terrestria, per Familias et Genera et Species Descripta. 319 pp. Copenhagen.

You can find a download here.

Names

Deutsch: Nasenkugelassel

Englisch: Nosy Roly Poly

Synonyms

• Armadillidium nasatum var. flava Collinge, 1918 
• Armadillidium nasatum var. nigrescens Collinge, 1918
• Armadillidium quadrifrons Stoller, 1902 
• Armadillidium sorrentinum Verhoeff, 1908 
• Armadillidium speyeri Jackson, 1923 

Subspecies

• Armadillidium nasatum mehelyi Verhoeff, 1930
• Armadillidium nasatum nasatum Budde-Lund, 1885
• Armadillidium nasatum sardoum Arcangeli, 1950

Sexing

In males, the pleopods are pointed and in females, they are rectangular. In individuals smaller than 5 mm the pleopods are not yet completely differentiated and it can be hard to impossible to sex those.

Generally, males are more pigmented than females but this is not a reliable way to tell the sex since older individuals tend to have more pigments than younger ones as well.

Reproduction

This species reproduces like other isopods. The female can store sperm and they breed seasonally from spring to fall. A colony can produce multiple broods per year.

Development

The offspring are born white and with red eyes and develope their colour after about two month. They are sexually mature after about 8 month.

Genetics

Red and darker forms are genetically distinct. Their red colour is usually a recessive trait and results from missing darker pigments. But there exist dominant versions in France and maybe Virginia, USA. Not every colony contains every colour morph.

• S. L. Adamkewicz. Colour Polymorphism in the land isopod Armadillidium nasatum.
• https://en.wikipedia.org/wiki/Armadillidium_nasatum
• https://de.wikipedia.org/wiki/Armadillidium_nasatum
• https://www.marinespecies.org/aphia.php?p=taxdetails&id=257751