My white coco worm is 3 years old. I find the difficulty in shipping them is making sure you direct phyto at them. I do it about once every 3 days when i feed my clams, i also shoot rotifers at him occasionaly. He was a little guy 9 months ago, he has grown probably an inch, i'm not sure how big they actually get, my white one hasnt grown at all in the time period i have had him.