Looks like an LTA, but would need to see the column and foot. If the column and underside of the disc has spots, it is more than likely an LTA. Google Long tentacle anemone and go through the pics that show up, but pay close attention to the foot and underside of the disc in the pics. From there, compare to your nem as a double check.
I think it’s BTA cause of the white spots visible throughout. I may be wrong, but I’ve only seen stripes on LTA, where as BTA’s occasionally have that splotchy white