i would say theyre a little less than a quarter of an inch long from nose to tail. way too cute! one has decided to live in that GSP. (that chunk is about the size of a quarter.)
not sure of their exact age, a member of my reef club gave them to me. he breeds them by the hundreds. i will try to get more pictures tomorrow when i have some light. its really hard to get a picture of them because theyre SOOO tiny and it takes about ten minutes to find both of them in their 5.5 gallon tank.