Randall's Prawn Goby Amblyeleotris Randalli Perciformes (perch-like) Actinopterygii (ray-finned) Care Level: Easy. If you have other more agressive fish, make sure to get him some food on the bottom (as they can/do sift sand). Make sure to keep a covered top as you should for all gobies, jawfish and similar swimming fish (fin array - get it? ray-fin, fin array ....boooo). Reef Safe: VERY Temperment: Very shy, especially in the first week or two of introduction. After acclimation to the tank will tend to be less skittish and jumpy (mine just hates the mag-float!). Be sure to make some caves out of LR so he feels secure. Can share a burrow with one or more pistol shrimp (alpheus - candy/tiger/etc). Diet: Carnivore. Zooplankton, Cyclopeeze, Mysis, enriched brine, and sinking pellet food for long term health. You can try flake, but mine has never aggresively gone after ANY food let alone swim to the top like a tang or clown. Origin: Western Pacific Sexing: Unknown but here are some possiblities. Watchman gobies - "not that difficult... males really do tend to me more colorful (sharper yellow and more blue spots) but more importantly... they have thicker lips (fighting/digging), a larger buccal cavity (chin pouch) and the first hard rays of the first dorsal fin are somewhat exaggerated (taller/spikier)" -WWM "Rather than trying to describe the relative and variable body shape and color differences between males and females, I'd rather encourage you to gauge which is which for the entire group via their genital papilla. immediately in front of their anal fins. You may need to use a flashlight; the males' are cone-shaped and pointed at the tip; those of females' are generally only visible near spawning and are short and rounded at the tip." 'mikestod' Max Size: 12cm : 4.72" Max captive: 7.62cm : 3" Minimum Tank: 10 gallon. Although IMO a shorter and wider cube (custom) would be acceptable as they don't swim often, they perch like hawks. Personal Notes One of the most adorable fish I've seen, and the PERFECT inhabitant for a nano reef! Definately buy from a LFS instead of online because some dorsal (tall/top fin) actually have some fluorescent/neon pigment to them. One of the most unique fish (as well as any shrimp goby) in that it burrows (or will use a burrow) like a jawfish, swims like a jawfish, but will perch on anything it pleases. I just added my pistol shrimp as this article was written so no firsthand experience yet As far as sexing the pistol shrimps, I assume that they, like other shrimp, are simultaneous hermaphrodites, and therefore can mate with any other shrimp.