Anemone Shrimp missing

I have, or had two Spotted Anemone shrimp established in a couple flower anemones, and a Pederson's Anemone Shrimp in a green ricordia.  Well established, eating and molting. After seven months all three were gone in one weekend.  Any ideas on the culprit? I really liked these guys and would like to replace them, but not as food . . . 

I feed frozen food three times per week, dry pellets twice daily.

200 gal tank w/ 10% water change weekly, parameters are 81 F, 1.021 SG, 400 CA, 3.72 Alkalinity, 0 Ammonia-Nitrite-Nitrate, Dose Iodine weekly.  Lighting 12 hrs daily by 2x140 w actinics, 3x250 W MH, circulation/filtration 3000 gph skimmer & return pumps, 27 gal sump, 2x1200 gph powerheads.

Inhabited by:

CORALS- Green Hammer, Yellow Porites, Yellow Palythoa, Blue w/green Cup Montipora, Pineapple, Met. Green Star Polyps, Thin Bar-PomPom-Tree Xenia, Silver/Green Alveapora, Candycane, Met. Green Galaxia.

CRUSTACEANS- Red Leg-Blue Leg-Scarlet-Blue Knuckle Hermit Crabs, Astrea-Nerite-Nassarius-Bumble Bee  Snails, Banded Coral-Scarlet Cleaner-Peppermint Shrimps, Emerald-Decorator-Anemone-Acro Crabs, Flame Scallop.

OTHER INVERTS- Yellow Cucumber, Sand Sifting-Harlequin Serpent-Red Serpent-Orange Fromia Stars, Encrusting Gorgonian, Purple Sea Blade, Knobby Sea Rod, Feather Duster-Coco-Cluster Duster Worms, Flower-Bubble Tip-Ritteri Anemones, Pink/Orange-Green Riccordia, Purple Fuzzy-Lavender Frilly-Giant brown-Green Stripe-Red-Orange/Red pimpled-Umbrella-Bullseye mushrooms, Yellow-Pink-Brown-Green-Orange Zoanthids.

FISH- Lawnmower Blenny, Pigmy-Coral Beauty Angel, Green Chromis, Bangaii Cardinal, Four line Wrasse, Purple Pseudochromis, Mandarin-Red Scooter Dragonets, Pearly Jawfish, Bicolor Anthias, Black Ray- Dragon Goby, Yellow Tang.

MACRO ALGAE- Halimeda, Pine Cone.

Stonogobiops nematodes: commonly known as Filament-Finned Prawn Goby, Threadfin or Hi Fin Red Banded Goby, and Black-rayed Shrimp Goby.  

I had suspicions of the Coral Banded Shrimp, and the Purple Pseudochromis.  However, I have not observed anyone picking on these guys.  They just vanished, even though their territories were a couple of feet from one another.

1mariner7 wrote: Stonogobiops nematodes: commonly known as Filament-Finned Prawn Goby, Threadfin or Hi Fin Red Banded Goby, and Black-rayed Shrimp Goby.

Thanks for that.  Good thing we have Latin, I call them rose gobies, but I don't know why I call them that.  He isn't the problem, so nevermind on that.  I'm still thinking shrimp (only because of how aggressive BCS are to each other).

Adam