The picture content is not available but looking at your zone, the grass most often confused with crabgrass is dallisgrass. When you write back, tell us where you live.

According to the info on "kikyu grass", kikyu looks similar to "St. augustine". The stuff I was asking about is very thin, much thinner than a blade of "St. augustine". That's why I thought it might be bermudagrass. The scan is perhaps misleading because there's no reference in the shot like a penny to gauge the size of the blade. My bad. The scanned plant section is actually about 3 inches top to bottom.

Best I can tell from the photo is chickweed and POA Annua. The chickweed is pretty easy. A little Ortho Clover, Chickweed and Oxalis killer should take care of that. The POA Annua is going to be a problem. A few treatments of Tenacity should do it but the seeds it is dropping right now are going to give you trouble for several years. A good pre m plan and careful use of Tenacity should keep it under control.

So no one can come up with a clear cut answer ... now you know what I've been going through .. I have used grass killer in the past to reseed