Porcellio Expansus is one of the largest species in the hobby today. They're actually the largest in terms of width with their oversized expanded serrated skirt. They can reach lengths averaging between 1 to 1.4 inches! Their striking coloration, larger than average size and almost alien like appearance make them a highly desirable addition to any collection. The orange version as shown here was selectively isolated and line bred to enhance this appealing genetic trait.
Porcellio Expansus like most other titan isopods is endemic to the mountainous regions of Spain. Their environmental factors in the enclosure are vital if they are to succeed as a new culture. In the wild they can be found inside of caves or in and around rocky structures and other similar formations. Despite the seemingly almost universal consensus that all titan isopods need a very dry set up, we have found this is not entirely accurate for Expansus. Inside of caves and such is higher humidity, but in the right spots there is also ample and plentiful ventilation and this is one of the larger needs this isopod must have to thrive. There is no one size fits all answer as how to provider this because all of the variables that will affect any given enclosure will be different based on the type of enclosure, the size, the ambient climate in the location in which they are kept are just a few that will require fine tuning to fit your exact circumstances. Providing a thicker substrate one one side will help retain moisture longer and multiple hides throughout the different micro climates in your set up should give them several options where they can best move to what suits them at any given time. Just avoid letting the air inside the enclosure stagnate while keeping a close eye on the moisture level so they don't dry out and expire. For temperature, average room temps of 69-78F with a modest night drop are no problem. Avoid large sudden fluctuations as these isopods don't fare well in these conditions either.
A minimum 10 gallon glass tank or 12qt gasket sealed sterilite bin is highly recommended for a starter colony of 12-15 individuals. Since this is a much larger isopod than the typical fare, we recommend this larger footprint to accommodate them. Standard or bioactive enclosures can be enhanced with natural botanicals to simulate the isopods habitat in the wild. This helps them feel secure which in turn promotes their natural processes like eating and breeding. There is more to this than the practical statement of a bigger isopod needs a bigger enclosure. Mature males of P. Expansus are highly territorial and if they are forced in a set up that doesn't allow modest spacing they can quickly and easily die of stress. The same applies for the females since it will be harder for them to escape "eager" males looking for attention. Providing as many hides as practical will also help minimize these conflicts which should also be a top priority because P. Expansus has been known to cannibalize to some degree if food and space are minimum. Males are easily identified by their long showing uropods while the females will be a bit small in size with smaller uropods.
Isopods are detritivores. Their primary diet in nature is dried leaf litter and rotting decayed wood. Both of these should always be available in abundance. They will also happily consume any other decomposing organic plant or animal matter they come across. As such it is vital to supplement your isopods with other food sources on a semi regular basis. They enjoy food options like squash, radishes, carrots and other veggies along with commercial isopod powdered food like Repashy Morning Wood. This designer isopod will eat these and all of the typical food options. But like most Porcellio, they are very fond of protein based foods like freeze dried minnows, shrimp pellets, fish flakes and dried insects.
Porcellio Expansus is likely a "goal" for any isopod keeper who enjoys all of the different species and their unique characteristics. There are certainly few that even qualify as similar in terms of looks to this amazing creature. If you have more than minimal experience with isopod keeping and have a solid grasp on their husbandry along with the many variations of it needed for different types, P. Expansus may just be the next exciting step in your journey!
Quick Facts
- Origin: North Eastern Spain
- Classification: Porcellionidae > Porcellio > Expansus
- Characteristics: Medium to bright oranges accented with random white splotching along the pereon. Large in size, especially width.
- Average Size: Around 1.2 inches at adult size
- Activity level: Primarily nocturnal and active at night
- Difficulty: Advanced