The purple stage of life

A few days earlier, during a night dive, I spotted a small purple ball darting around at incredible speed. It would crash into the sand, then suddenly shoot back up, repeating the same erratic pattern. I managed to take a few shots, but later, reviewing the photos, I realized they were all blurry. Still, I was determined to find out what this tiny creature was, as I had never seen anything like it. After some research, I discovered it was a megalopa (a larval stage of a crab). I was thrilled to have seen it, though disappointed not to have captured a good photo. We returned to the same site for a day dive. Near the end of the dive, our guide suddenly turned around, clearly excited, and pointed at a small ball. This time, the tail was missing, but the purple head and large, adorable eyes were unmistakable. It was either the same megalopa or another one. Unlike the night dive, it was easier to photograph. But after just two shots, it suddenly burried itself in the sand and disappeared, never to be seen again.