Could be. When you planted the seed, did you water it lightly 3x per day for several weeks until you got about 80% germination? And does it seem to be uniformly the same grass? If so, then there's an excellent chance it is the zoysia seed you planted.

Zoysia can be hard to identify because it comes in two different basic forms, coarse and fine bladed. The picture appears to be a coarse bladed grass but not as coarse as St Augustine or crabgrass.

It looks thin for what I would expect at this stage of life. What has been your watering regimen over the summer? How often and for how long do you water?

Thanks for your reply, What I did was remove moss added lime to get ph. to 7 (over seeded with Compadre and Perennial rye grass) mixed with the existing grass. used 10-10-10 and added straw then watered twice a day for 14 days. I don't remember seeing anything like this in the yard so I can only assume its what I planted its real low to the ground and from other picks on the internet it kind of looks like it.