frank, the blue-eyed hermit crab

Frank Sinatra, the blue-eyed hermit crab

Starting a marine reef tank is a lot like adopting a demanding, finicky child that eats its playmates and spends money like, well, seawater.

Fred Mertz* the reef tank has been alive for a bit more than a week, and definitely has taken over our lives. I wake to find the the Resident Carpenter crouched in front of the tank with a flashlight, peering into crevices and trying to find all our critters.

bagged cleanup crew in the store

We picked out 15 or so snails, crabs, and a small pistol shrimp for our first tank residents.

Every evening I grope my way off the walker and carefully descend the three stairs into the living room. Nathan (the Resident Carpenter’s real name) hurries over with a chair (I’m not quite up to standing for long periods of time yet). I sit in front of Fred, Nate crouches next to me, and we oooh and aaaah like a studio audience on a teleprompter.

Reminds me of way back when families huddled in front of the radio, except that radios rarely need nitrate readings.

Resident Carpenter acclimates cleaning crew to the marine reef tank

Acclimating the new residents to the tank

Fred’s still relatively critter-free because he’s “cycling,” whatever that means, and until he finishes, only the cleanup crew is allowed inside. Fortunately, the cleanup crew is pretty cool.

Jeff the Fish Guy sold us about 15 assorted snails, conchs, and crabs, guaranteed to run around eating tank detritus and cleaning off algae and stuff. He added a pistol shrimp, mostly because we fell in love with that little stripey bug. The pistol shrimp, he assured us, would be great for “sand turnover.”

We brought our new charges home in plastic bags half-full of aerated seawater, and followed Jeff’s instructions to the letter:

  1. Dump the bags into the tank and let them sit for 15 minutes so the water temperatures will match (we’re keeping the water at a balmy 76 degrees).
  2. Pretend not to see that the hermit crabs aren’t getting along in there. Or maybe they’re mating. Who knows?
  3. At the 15-minute mark, open the top of one bag and pour in a cupful of tank water, giving the critters inside a taste of their new home. Seal up that bag and repeat until everyone’s been given a drink.
  4. Give the critters in the bags another 15 minutes to acclimate. Not quite sure how you tell someone is acclimated, but I guess if they’re not dead, they’re fine.
  5. CAREFULLY scoop up each critter and drop him into the tank. DO NOT let the bag water escape into the tank, because we NEVER introduce foreign seawater into our pristine environment.

The critters tumbled onto the sand like so many pebbles, but pretty quickly started popping heads or other body parts out of shells and exploring. Within minutes most were happily chowing down on the sand and rock, and exhibiting quirks.

John the Conch cleans up. That's his incredibly long mouth sticking out.

John, the smaller conch, roams all over the tank, cleaning sand and rock. That dark, arm-looking thing sticking out of the shell is his proboscis.

Fighting conchs are kinda the speed demons of the mollusk world; almost immediately ours was tearing up sand and clambering his obscenely long proboscis up up up the rock.

two hermit crabs in a traffic jam

Two hermit crabs meet in a narrow passage, causing a traffic jam

The hermit crabs scuttled and tumbled over each other like puppies. Some climbed the rocks, eyestalks out and little feathery mouths going a mile a minute. A couple of ours have beautiful scarlet legs; others sport long blue eyestalks that watch us as much as we watch them.

“They need names,” said the Resident Carpenter. The blue-eyed hermit crab looked a lot like Frank Sinatra, he said, so he named all the hermits after the Rat Pack: Sammy, Dean, Rosemary, Frank, Joey, Peter…etc.

They were really cute…until Sammy starting bugging Turbo the snail, grabbing and poking at him, even turning his shell all the way over. Turbo ducked inside so that he wasn’t hurt, but it looked suspiciously close to bullying.

“It says here,” I said, peering online, “That the blue-legged hermits are aggressive and will kill snails for their shells. And that we can stop it if we put empty shells in there.”

We had a few shells from tidepooling on the coast, so we washed them and scattered them across the reef tank sand. Hopefully that’ll do the trick.

The reef tank lights simulate a sunny day underwater for 8 hours, then fake a sunset, gradually growing dimmer until the tank goes dark. We discovered that most of our salty denizens are nocturnal; the minute the lights went out, the party started.

aiptasia in our tank!

Aiptasia anemones are a tank pest. This one is about a half-inch across.

THINGS came out of the rock, tiny snails and little floaty leafy things and these beautifully crystalline micro-anemones that had long amber or clear stalks with a flowery head of tentacles on top.

The biggest anemone started out at no more than a quarter-inch across, but began growing almost as we watched.

Yay! Our first anemones!!!!

Well, not really. Sigh. Turns out these beautiful, delicate little critters are aiptasia, apparently the crab grass of the reef tank world. They’ll sting little corals and take over prime rock real estate, crowding everybody else out. Not much kills them so we’re supposed to prevent them from establishing a good foothold on our reef tank.

“There’s at least 40 of them now,” Nate counted, “Maybe we should do something before they become a real infestation. Do we pluck them out like weeds?”

“I don’t think so,” I worried, “It says here that if you do that little parts of them will fall off and make even more anemones, like The Sorcerer’s Apprentice. You can inject them with lemon juice, that’ll kill them…”

We looked at all those tiny transparent sunflowery things, waving tentacles ALL OVER OUR ROCKS…uhm…no. Clearly injectable lemon juice was not a scalable remedy. “It says that Peppermint Shrimp like to eat Aiptasia…” I said.

seawater on the wood floor

One thing we’re learning about reef tanks: The floor will get wet.

“We don’t really have enough cleanup crew anyway,” added Nathan, reading over my shoulder, “It says here you need at least 75 for an 80-gallon tank and we only have maybe 15. We should get more, and then get a Peppermint Shrimp while we’re there…”

Preparing to let hermit crabs into the tank

The Resident Carpenter adds water to the bagful of hermit crabs awaiting release.

…which is how we ended up in a different marine store the next day. We bought a boatload more hermit crabs and snails, another conch plus three more big flat crabs to go with the first: A green emerald crab slightly bigger than the first, one white emerald crab, and a nocturnal strawberry crab that’s the most gorgeous salmonberry color and stays hidden until dark.

“They have really big forearms. Let’s name them after big-time bodybuilders and wrestlers,” said Nathan. So we welcomed Arnold, Jesse, Lou, and Hulk.

I followed a new little swimming thing for about 15 minutes, trying to figure out its genus until I realized it was conch poop. Conches eat a lot, apparently, including algae from each other’s shells. They’re currently the biggest things in the tank and we’ve named them John and Ron. I’m not even going to start explaining why, but if you see them (and watch a lot of, uhm, special movies) it’ll be obvious.

We’ve named the pistol shrimp Luke Sandwalker, mostly because he’s an incredible sand excavator. He’s dug (and filled in and dug again) a network of tunnels under the rock, pushing enormous masses of sand with his front claws like a skiploader.

He apparently wants a fishy companion to act as lookout, so once the tank is cleared for swimmers we’ll get him a goby. We’ve already named him: Goby Wan Kenobee.

darth vader, the peppermint shrimp, readies an attack on aiptasia anemones

Peppermint Shrimp like to hang upside down in caves, coming out at night to eat the Aiptasia.

And we picked out a Peppermint Shrimp. She’s red, white, and transparent, with ginormous waving antennae and a voracious appetite.

She landed in the tank and got to work; by morning there was only one little Aiptasia anemone left. Shortly after she decimated the Aiptasia, we found her bouncing a snail around like a basketball.

Keeping with the shrimply Star Wars theme, she’s become Darth Vader. Let’s hope her appetite doesn’t expand to include her neighbors.

*We gave Fred the last name of Mertz because Marine Reef Tankz = MRTZ…