12/30/2021: Lava Lucy Porcellio scaber, the nail in the coffin for “LiNeS dOnT mAtTeR” hold outs?

At the uptick of the modern isopod age circa 2016, I was extremely vocal about tracking various isopod lines. Having isolated many popular mutants and crafted numerous strains (among them mainstays such as Porcellio scaber “Dalmatian”, Armadillidium vulgare “Orange Vigor”, and Armadillidium vulgare “Magic Potion”, more on the last one later) and watching lines get mixed, matched, and names slapped on bastardized cultures like there’s no tomorrow, I find myself clinging to my old reliable, tried and true-breeding cultures as I am certain most outside lines have been compromised.

It’s now common when inquiring about strains for vendors to have no idea as to their origins. Worse, when purchasing those that should be bona fide, true-breeding without question, such as Porcellionides pruinosus “Orange”, to hear “oh they throw powder blues occasionally”. The implications here are concrete: true-breeding and point-source stock has become a rarity.

But does this matter to the average keeper? Probably not… but the isopod hobby was built on a strong foundation of many small-scale breeders and keepers honing and carefully selecting their home-grown strains to create nifty, living works of art. Mixing genes all willy-nilly may not matter to someone who just wants to keep a species (though they should be rightfully miffed when their simple recessive oranges produce half wild types in the F1), but it is imperative to those wishing to linebreed and create novel strains that the stock they work with is consistent and well-defined. It is far easier to propagate a consistent line by combining known traits than to desperately pull unique individuals out of a simple recessive cesspool like “Lotto Ticket” only to find out by the F3 that the phenotype you desired was actually a heterozygous for orange.

At the forefront of this, I may have discovered something that will shatter the argument that for simple recessive mutations, line tracking does not matter.

I have been working meticulously over the years with numerous Porcellio scaber lines to unlock novel colors and combinations. Sometimes, I hit a brick wall, and a project ends; sometimes, the results aren’t what I’m hoping for.

While crossing a prototype line for the phenotype I’ve been aiming to call “White Tiger” to “Lava”, I noticed that there were solid white isopods in the F2. The original “White Tiger” stock originates from California and notoriously produces black-eyed, white-bodied isopods, which I isolated and named “Lucy”. This is where things get interesting.

To have produced these solid white individuals in the F2, the most likely explanation is that they are the same mutation as found in “Lucy”. This is congruent with my work with the prototype “White Tiger” line; hets. for leucistic tended to have the superior “White Tiger” phenotype. This incomplete dominance can be seen in a prior blog post.

The real kicker is that these Lava Lucies, unlike their pure California genetics counterparts, do not have black eyes. This suggests that the “Lucy” gene expresses differently in scaber with some “Lava” genetics… presenting what phenotypically is a genetic “White Out” in eastern United States scaber stock.

So what does this mean? It means that depending on the locality of scaber, the phenotype of a very specific and well-known genotype can be radically different, so much so as to resemble a completely different genotype. For selective breeders and people tracking their strains, this is huge.

I’ve isolated one of these Lava Lucy females to grow to a fair size before introducing a true-breeding male in order to guarantee she hasn’t been fertilized. I’m unsure which test would be ideal: using a “White Out” male or a “Lucy” male. The former would produce very stark results; if these Lava Lucies are actually random chance mutant white outs, then the first generation will be all white outs. If they’re actually Lucies, then the first generation should be almost entirely wild types with very light coloration. A male Lucy could be interesting too: half black eyed and half white eyed babies would suggest there is another factor affecting the expression of that trait conveyed from “Lava”, since “Lucy” always have black eyes. This would also definitely prove that the same gene is responsible for the phenotype in both the pure “Lucy” and in the “Lava” crosses, as different genes would result in similar results as the predicted “White Out” cross.

So I’ll hold my breath before screaming “I told you so!” at the greater isopod hobby, but for now I’ll try to keep the anticipation at bay.

For those bored with some of the technical language here and just wondering about the”White Tiger” scaber, I did end up creating that phenotype in a different line that doesn’t produce leucistics. Attached is a picture of the old project that was related to the “Lucy” line for reference, but the phenotype is the same in the new line. I’ve created a page for the new line, but haven’t gotten a photo to represent the new stock.

-Kyle