Friday, March 01, 2013

Feeding time in the tank

My aquarium "how-to" bookshelf holds only three books, which I re-read frequently, and which all give conflicting information. Living things are like that; almost any rule about dealing with it has exceptions. So I read a chapter in one book, the related chapter in another, then go commune with my critters. They have their own ideas.

The books:

  • The Conscientious Marine Aquarist. 1998. Very good, very detailed, well written. Most of it is not relevant to what I'm doing, though; the author's interest lies in the tropics, and the exotic species, whether or not they live together in the wild.
  • The Saltwater Aquarium Handbook. 1991, 2000 edition. Much smaller. Good info on equipment, skimpy on invertebrates. Emphasis on purchased specimens, warm water animals, exotics.
  • And the Marine Aquarium Guide. DeGraaf, 1973. Out of print. Dense. Very technical; a lot of chemistry and detailed engineering. A variety of methods and their explanation; choose your own. Extremely helpful, even though I followed none of the methods described; at least I know what to aim at, what to watch for.

And of course, there is plenty of information, usually contradictory, on the web. Reef aquarists forums are helpful. Here's a sampling:

And then, there's the local aquarium store. Which usually doesn't carry what I've seen discussions of, and I have to wing it. Still, they sold me my tank and filters, and 20 kilos of sea salt for aquariums; that's what has kept my critters happy this winter. And they sold me the hermit food.

Hairy hermit, with his breakfast of Crab Cuisine.

So, what do my guests order from the menu?

The hermits love the Crab Cuisine, even though it was not specifically designed for underwater hermits. It sinks nicely to the bottom, but after a bit of nibbling, it tends to crumble and float away. Val, the burrowing anemone, grabs pieces that float by, but eats them slowly. After a while, the hermits, having finished their serving, go prospecting in the anemone mouth for leftovers, which the anemone yields up without a whimper.

The crab (I only have one at the moment) can't do this. He loves the CC. He grabs a piece and runs off to hide in his latest burrow to eat in peace. Later, he may approach the anemone, but the venomous tentacles drive him off, and he gets to sit looking at that tempting chunk of food until a hermit walks in and takes it, right under his nose.

In a Chinese grocery store, I bought a bag of dried minnows, intended for human consumption. Nothing but fish and salt, the label said; it would be safe. I flake a half minnow into the water now and then; everybody is pleased: the crab, the hermit, the anemones, and any polychaete worms hiding in the sand. It does foul the water, though, so I like to offer it just before a water change.

Another Chinese food store, recently: I found a bag of dried shrimp, very tiny baby shrimp. Opening the bag at home, I realized that they were only partially dried, and still soft, so they're in the freezer. And this is dessert! As I drop a piece in front of one hermit, all the animals with legs start running in his direction. Fights break out, unusual in hermits. The largest grainy hand, the absolute pacifist, even attacked my finger. The crab abandons his hiding place to grab at the shrimp, and the hermits fight back. I drop more tiny pieces, a quarter shrimp at a time, scattered around, to break up the fights.

Some of the hermits take their prize and climb to the top of the eelgrass or a stalk from a kelp holdfast, where no-one can sneak up on them. Others just stand their ground, tugging away at another hermit's catch.

Nassa, hurrying.

And a minute later, the Nassa snails appear, as if from nowhere, heading purposefully towards the biggest chunk of shrimp. They will stay with it until there's nothing left.

Val, on a normal day. (No shrimp.)

What of the anemone? The books say (two of them) to offer a small piece of shrimp, touching the tentacles with it. Another book says to blend the shrimp, turn off the pump, and spray the anemone with the shrimp paste. I didn't get around to that, because an entire shrimp escaped my fingers in the tank, and floated past the burrowing anemone. Instantly, a tentacle lashed out, snared the shrimp, and crammed it into her mouth. The whole shrimp. And it vanished.

Val swelled up to her full size, column as high and as wide as I've ever seen it, tentacles waving enthusiastically. (Did you ever see an enthusiastic anemone? I have.)

I've fed the tiny orange striped anemones baby-sized bites. They're slower to grab the food, but when they do, they don't let go.

Val really doesn't need feeding. She manages quite well on her own. I saw her snatch a swimming amphipod.  And recently the crab molted. The old molt floated by, and Val grabbed it. It was wider than she is, and all legs and carapace. Never mind, she swallowed it, slowly, one leg at a time. The next day, she regurgitated the polished carcase.

And she had positioned herself under the pump. I didn't notice, but a fair-sized periwinkle snail was on the side, and when I went to remove the pump for cleaning, the snail let go and dropped. Right into Val's mouth. I quickly got my handy chopstick and tried to flick the snail out; no way! She closed right down, tight, a green ball with a pursed mouth, and the snail hidden away inside. Sorry, little snail.

The next afternoon, one of the hermits was wearing the newly cleaned periwinkle shell. Life goes on.

1 comment:

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