Cute Crustacean Conundrum

While writing my previous post about spawning aggregations in Palau, I rummaged through photos from my last visit to the island nation and found this:

blackwater diving palau, crab megalop
Unidentifed crustacean that desperately wants to be a manga character

Anyone know what this is?

These critters were relatively common during late-night blackwater dives. They're small, like half the size of my pinky fingernail or smaller, and they zip about in erratic patterns, making full use of their multitude of multi-jointed appendages.

Given their diminutive proportions and penchant for Brownian motion, they are incredibly frustrating to photograph.

palau blackwater diving palau, crab megalop
Front view of the critter's paws claws

They come in a range of colours. Besides this orange and magenta pattern, I recall seeing deep purple, as well as tan. I wouldn't be surprised if there are more variations.

I'm thinking these manga-esque critters are larval crustaceans of some sort.

If you know what this animal is, please clue me in!

[Update via Jody Martin (crab curator) and Leslie Harris (polychaete worm expert) at Natural History Museum of Los Angeles: Likely the megalop stage of crab development, which is the final pelagic stage before settling down to change to benthic form. Possibly Carpilius juvenile.]