This morning I saw in the same spot an empty shrimp exoskeleton.
Consider this a 1/2 period for the molt of each shrimp.
I assume that last night the other of them two molted.
this way for months - each one molts when other is not.
I was attempting breeding these shrimps in my fishtank.
Synchronisation was exact to a single day.
Two bunco shrimps (Lysmata amboinensis) accepting a quicky in my catchbasin ) Last night, about 1:00am with lights off but ambient ablaze from the room ablaze I noticed a beginning abandoned exoskeleton of one shrimp and two shrimps blind out next to it.