HCA: Hermit Crab Association

so i just want to know how old the pet store keep the hermit crabs at so I can differ how old they are now so I can keep the age marked down for their birthdays. thanks

It is nearly impossible to judge the age of hermit crabs. Depending on conditions in the wild they will grow at different speeds. Even tiny crabs that are in stores in shells the size of bottle caps can be several years old. Crabs in golf ball sized shells can be 10+ years or older. Jonathan Livingston crab has been with the same owner since 1976 and he is like a softball!

We are just starting to learn how baby crabs grow. Mary Akers, mlakers on here is one of six people in the world to successfully breed hermit crabs in captivity. She is also the only person to do so in the US. She has also managed to get over a thousand baby crabs onto land in the last 2-3 years, Way more than anyone else on the planet! Last year we were lucky enough, along with 25 or so others to adopt six of her captive bred babies in July of 2019 at the first Crab Con. The babies we adopted were born in late summer/early fall of 2018. So in July they were sill under a year old. With adopting the babies we are all measuring their growth, behavior changes, shell preferences, and tank conditions . We submit all our information quarterly then Mary and her assistants log the information. The information gathered will be pretty interesting once we have several years of data. With just having the initial check in in July, one in October, and second in January we are only at the very beginning of this interesting journey.

I apologize on going on the baby topic but I really think this is pretty big with learning about hermit crab growth and who knows what else.
Here is a link to when we first brought home the babies. You can see how tiny they are at just under a year. They also don't have much color either.
viewtopic.php?f=8&t=120581&p=1087862&hi ... s#p1087862

so would it be right to assume that are at least 2-3 years of age for a healthy golf ball sized crab?

Possibly older. My wife Xenocrab has had Triple H for about ten years and he is about golf ball size. So he may be 15-20 years old. Some crabs really grow fast and others very slowly. We just keep track of when we got our hermit crabs and don't really worry about their age. You can make them whatever age you want!

There are some generalizations that can be made by their size. A golfball sized crab is going to be about 8 to 10 years old, possibly even up to 15. It has a lot to do with their diet and often they could safely moult, and also if they ever had any injuries to repair. Leg thickness also comes into play, as they sometimes plateau on growth and instead focus on tanking up.

None have any injury 2/3 have had one safe molt and 2/3 are tanky.