Tunicates would be my guess too. Google the term spelled this way for more info on them, they have been around for a very long time. Interesting reading. If they are there are no issues to worry about. A month old tank may be a bit too soon for hitchhiker sponges to grow, their spores usually take longer to germinate. Few live sponges ever survive the air exposure during shipping and introduction of new live rock. But in a year or so the sponge spores that do survive start to show up if conditions are good. Just sitting back and seeing al the little things spring up is some of the fun............
Welcome to the Boards and to the new obsession too!