We had some friends over the other day and my boys were showing them the fish tank.  We’ve kept the whelk egg case between two cockle shells for protection from the urchins.  Turns out they’ve all hatched so we can move the top cockle shell away. 

Earlier in the day a murex snail was sitting at the opening of the cockles just hanging out.  When we picked up the top shell we discovered the murex had laid eggs underneath (thankfully not on the whelks lying inside the bottom shell).  It looks like a bunch of chopped pasta stuck together.   So cool.  It should take about 3 weeks for them to hatch.  I recently found our 5 gallon tank in the storage unit and I will set up a “birthing” tank for all of these critters, just so the eggs will hatch instead of being eaten.