So, this newbie is a little dissapointed. :c

I worked to purchase a lesser genetic mutator from the scale shop, and I used it on a captured themed pet, but, although the pet says it was genetically modified, there was no gene added. This leads me to conclude that LGMs don't work on Themed pets... I assume? I read the description of the item and thought that because I captured the themed pet, he was eligible for the mutator.

I checked through the guides but I couldn't seem to find any direct information relating to this or the proper use of a lesser genetic mutator. I even tried checking out a wiki site but it seems to be outdated. I've enjoyed this site a lot, but I've struggled a bit with finding helpful, comprehensive item use info. ^^;

It means that your pet got a carried trait somewhere. You just can't see what it got until it's been tested. I can test your pet for you if you'd like? (I'm about to go grocery shopping right now, but I can do it when I get back.)

Oh! That is very helpful to know for the future. I feel pretty silly now. ^^;
That would be just wonderful if you could do that! Thank you ever so much :)

You'd be surprised how common this question is. ;)
In case you've never had your pets tested before:
In order for another user to genetically test that pet, you have to set the pet up for a 1 gold reserved sale for that user. On the pet's profile page, go to "Manage Pet", set for "1" next to sale price and next to "Sell to User ID" set the ID# of the player testing the pet. In this case, my ID# is 7661. Then click on set prices~ Make sure to add the link to the pet so I know which pet you'd like me to test. After picking up your pet, I can then test it for you and sell it back to you for the same 1 gold price.

Just as a note, you should try to make sure to have a trail when you're getting a pet tested. What I mean by that is have proof either via private message, the forums or a screenshot of a chat log. (Might not be needed because players on Sylestia are pretty honest, but it never hurts. ;) ) There are some players who have threads in the Groups, Guilds and Services forums specifically for genetic testing~ Grape's and SkyRaven's threads for examples.

Thank you very much for the guidance!
I have set up my pet for sale to you to be tested, so it's all good to go. ^^

https://www.sylestia.com/view/pets/?petid=4467376
It will be this guy here, Borlas. :)

Thank you so much once again!

No problem~ He's ready to come home to you. :)

Thank you very much!! :D