Horseshoe Crabs

We walked the beach today, and it's the season for horseshoe crabs to molt. changing their shells for the year (with that said, horseshoe crabs do not observe the Julian calendar, in part since they have been around long than we have--approximately 300 million years.  Horseshoe crab Mom to child:  "In another few million years, humans will show up and try to impose a calendar.  Do not worry, this too will pass.")   

Anyway, we saw dozens of their shells, discarded along the beach.  We have seen shells as big as 15" in diameter.  Today we saw the smallest shell we have ever seen, it was no more than 3" wide.  Knowing these are long-lived animals, we wondered about how the progression took place.  It is said that horseshoe crabs grow 25% each year.  So, after they shed that snug-fitting old shell, they are fitted for a new one 25% bigger.  I had a mental picture of my mother's twice a year trip to a discount shoe place on Taylor Street in Chicago.  She would have been pleased to make this trip just once a year, but with three growing boys, we had to be fitted with new "shoes" twice a year.  I know we drove her crazy in those years, growing our feet as we did.  She was glad to be getting those shoes at  discount, but she would have been happier if we weren't growing as quickly as we did.  

Back to the crabs, they molt 12 to 16 times before reaching adulthood.  If the math is right, they grow up to at least 15 times their size.  I don't think human shoe sizes are proportional. but growing 2 sizes in a year was not unusual for us.  I think we wound up 11, 12 and 13 in shoe sizes.  Ultimately, I don't think mama horseshoe crabs have to pay for the kids new shells.  

I don't know if horses have to be fitted for larger shoes as they age, maybe they do.  But, I know they don't get to swim out into the ocean to change their shoes, and neither do us humans.  Remembering those trips to Taylor Street, I think we would have rather gone to the beach for our shoes, but my Mom would still have been crabby about the cost.  Love you, Mom.