Last week I brought home another porcelain crab for my little reef.
Although larger than the other two, the new addition looks almost identical to the existing porcelain crabs, Face and Hugger. I’d originally named her “Hold” but after discovering that the new crab was both female and gravid (egg bearing, aka “pregnant”) my son persuaded me that she needed a name more in line with the “Alien” theme of the other two.
We’ve named her Ripley.
After completing her acclimatization hold, I released Ripley into the tank. She swam immediately into a large cluster of blue-green palythoas, where she perched, apparently thinking herself invisible.
It took a hungry Ghillie less than five minutes to spot her there. He leaned in close for a better look, waving slightly as if to mimic the movement of seaweed (an instinctive predatory behavior for hunting syngnathids). I worried Ghillie might try to eat her – and with good reason, since he’s gone after crustaceans before and eaten several peppermint shrimp. He’d never shown an interest in crabs, per se, but one can never tell what a seahorse might decide to do when faced with crustaceans of delectable size.
Fortunately, Ghillie passed on this particular morsel.
Ripley spent the night in the palythoas, but by morning she had moved to the front of the tank and taken up residence in the anthelia where Emo the clownfish lives. Face resides there, too, though Hugger has moved to the back of the tank (after losing a turf war over the anthelia in question).
Face and Hugger are males, so Ripley’s presence didn’t bother Face in the slightest. For her part, Ripley seems content to wave her “fans” in the current and eat–both in the light and when the lights are out.
I was asked, on Facebook, exactly what a filter feeder finds to eat in a closed aquarium system. The answer is “Reef Nutrition!” I buy a variety of liquid foods, including live plankton, “oyster feast” (a combination of oyster tissue and oyster roe), and R.O.E. (a combination of oceanic fish eggs), and I feed that to the tank on a daily basis. The filter feeding corals, feather duster worms, and porcelain crabs react to the food the minute it hits the water, and strain it out of the system within hours.
In addition, the pipefish and seahorses macerate their frozen shrimp and blow out “clouds” of particles which also enter the water flow and get strained out by the filter feeders in the ecosystem.
Maintaining a reef is more complicated than dropping flakes in the water, as I used to do in my freshwater fish-keeping days, but maintaining a living, multi-layered ecosystem is more than worth the extra care and trouble.