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The Orange Mutation in Different Isopod Species

The orange mutation is the most frequent mutation distributed and isolated in isopods. The exact cause of the mutation hasn’t exactly been identified, but it is likely a tyrosinase positive (T+) connection, as orange mutations will typically display dark or black eyes and are not considered albinos.

Scaber orange morphs; Top Spanish orange and orange embers, bottom orange dalmatian and orange koi.

The first orange mutation was discovered and isolated in Porcellio scaber in Europe 10 to 15 years ago. This mutation was probably what allowed isopods to gain traction in the reptile hobby. Initially, isopods were only used as a clean up crew and feeders for small animals, especially dart frogs, but the orange gene in P. scaber is what really started to key people into the possibilities. Most orange scaber are descendants from the European line and are labeled “Spanish orange”, but there is also a US line being traded titled “USA orange.” The orange gene has also been worked into other morphs of scaber. When orange is combined with “dalmatian”, the product is “orange dalmatian” scaber. And when combined with “koi”, oranges make “orange koi”. While all these expressions of the gene do not have dark pigments on their body, they do have dark eyes. Additionally, there is another expression of orange in P. scaber that is called “orange embers”. This culture has a genetic trait that was line bred to express its appearance that is a bright white that fades to the back of the animal.

Pruinosus are dusty orange boiis

The next most common orange mutation is found in Porcellionides pruinosus. The common name of pruinosus is “powder blue”; so, the orange expression is aptl y called “powder orange”. The powdery appearance comes from waxy secretions that pruinosus creates as a method of protection. These secretions are discarded with every molt and builds up in between molts. A very “powdery” pruinosus may even take on a yellowed appearance. Some people are working on a pied orange pruinosus.

Top: Vulgare orange vigor, bottom vulgare tangerine.
A. vulgare "orange dalmatian"

The orange mutation in Armadilladium vulgare is called “orange vigor”. Vulgare is interesting in that the pigments deepen over time, and an incredibly old orange vulgare can sometimes look so deeply orange it appears red! An additional line of orange vulgare isolated out of the “Punta Cana” locale that has been called “Tangerine”. “Tangerine” are typically a light orange but can also deepen in color over time. The distinguishing feature between the two is orange vigor typically is yellow spotted as seen in American vulgare, while tangerine has bright yellow stripes in between segments. The third orange vulgare was isolated in America and named "sunset". Sunset has a range of colors from a dark yellow to a deep red. An orange dalmatian vulgare, which has a white base and yellow and orange spots, has also been combined and isolated from the American magic potion line of vulgare.

A. nasatum "peach"

Armadillidium nasatum has two recognized strains of orange; these are the same gene, just isolated by different people in the US. The “orange” line is older (originally isolated by Orin Mcmonigle) and displays deeper colors and more variation. “Peach” is the newer line isolated by Roach Crossing, that tends to be lighter and have little variation in the color. “Peach” is more widely traded, likely due to the name being more attractive more than the actual culture contents.

P. laevis "orange"

Porcellio laevis expresses in an orange mutation that is simply called “orange”. Sometimes individuals in orange cultures display white markings along their back, but it is the only culture truly known for being orange in the laevis species. Some laevis in the “California mix” cultivars display a bit of orange coloring.

Oniscus asellus "maple orange, B.C."

The orange gene in Oniscus asellus is traded under the name “maple orange”. There are two recognized lines of maple orange; the original being from the right half of North America and the second isolated from the left half. Or at least, that’s how I understood it. I could be completely wrong, I’m an isopod breeder, not a geographer. The second was given the cultivar name “maple orange, B. C.” to differentiate. The B.C. cultures are noted to breed considerably faster. Both lines display beautiful yellow spots framed by the vivid orange base.

Armadillidium werneri "orange". This guy is shedding and a bit duller than normal.

Armadillidium werneri is another species that has the simple name of “orange” for its gene expression. This is a relatively new isolating of the gene in this species, so there is not much variation between cultures. Orange werneri have an orange base and white spots.

Armadillo officinalis expresses orange in a culture that has been named “red”. This expression of the orange gene is very deep in color and is certainly deserving of the red title. When approaching shed, red officinalis takes on a pink color, and fresh out of shed the edges of their segments are outlined in an exceptionally light color.

P. magnificus in all their glory

While not officially a morph, Porcellio magnificus are brightly colored, all orange animals. This is how the species naturally presents in nature, so whether this is an animal that evolved over time to be orange or the competing members with the orange gene are the ones who survived is anyone’s guess.

Porcellio expansus "orange"

Porcellio expansus doesn’t have an orange mutation, but it does have a locale of the species that displays lots of orange. Porcellio expansus ”orange”, sometimes called “orange skirt” has orange coloration to the typically white skirt. Classic expansus have white skirting, but expansus collected from northern Spain have orange coloring. This trait was additionally line bred to be more saturated and vibrant.

Agabiformius lentus "kumquat"
Venezillo parvus "persimmon"

Species are beginning to display the orange mutation in captive bred populations constantly. Our personal projects include the orange mutation in both Agabiformius lentus we have called "kumquat" and Venezillo parvus we have called "persimmon". Isolating between different species is exciting because how the gene is visually expressed can vary so much!

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