These shrimp are not super rare, but are very very rarely seen. The reason for this is that they live underneath Crinoids.
Crinoids, or Feather Stars (as they are also known) are echinoderms. There are many of them in Lembeh, but these shrimp seem only to live under the orange coloured ones.
You can very carefully turn the crinoids upside-down to see these wonderful critters.
They are called ‘snapping’ Shrimp, as they can ‘snap’ their large pincers to create a loud noise. As you can see, one pincer is always much larger than the other. You can also see that it can be either the left or right pincer that is the large one. This pair has one partner with a larger left pincer and the other with a large right pincer. Why this is the case, I have no idea.