Your mileage may vary. Probably does.
Marine invertebrates are just as individual and persnickety as we humans. Some are more adaptable than others, but they all have their limits, and their needs are comparable to ours.
Here's a partial list of what they may consider essential; different variants of:
- Water: purity, temperature, movement, oxygen content, pressure (depth), tide schedules, salt content, nutrient content.
- Light: from none to bright sunlight.
- Substrate (floors, walls, mattresses, in our world): hardness, chemical content, mobility, edibility, thickness, depth.
- Sound: does this matter to them? It might be something to research.
- Food: where is it found? Size, movement, live or dead, plant or animal.
- Schedules: night and day, tides, seasons.
- Community: do they like to live alone, in pairs, or all piled together indiscriminately? Do they tolerate other species nearby? Are they aggressive or cooperative?
When the conditions in my aquarium are not to her liking, my big anemone lets me know, in no uncertain terms. Pollution in the water? A dead clam smelling up her surroundings? Too much salt, due to evaporation? She shuts her mouth, pulls in her tentacles, puckers her skin disapprovingly. Too much light? She pulls back slightly. Crabs tickling her, or sand on her pedestal? She slides up and away. No water? Like she would do on the beach at low tide, she goes limp and droops, letting gravity stretch her to twice her length; imagine a wet bag full of jelly. (Here's a photo.)
She doesn't like the heat. She's a cold-water animal, and she won't put up with carelessness in the matter of her cooling requirements. A few extra degrees, and she spits out water, makes a button mouth, and flattens herself down against the glass.
|Herself and some cousins (or clones), all sulking in the afternoon warmth. Reflected in the water surface.|
I was surprised by this; walking on the beach at low tide, I often step into tide pools that feel as warm as a tub bath. The next pool may be cooler, the incoming rush of water quite cold; the intertidal critters seem not to mind the changes. The anemone does.
This particular anemone has been living with me for over two years; we've had a couple of hot summers, and while she grumbled some, she always got over it in time for the evening meal. Not this summer. She spent so much time as a brown pancake that she started to lose weight; even now that she's eating again, her footprint is 5/8 inch, compared to the 1 1/4 she was last spring.
We had a cold July, which was fine with her, and at least gave me a chance to clean out the chemical contamination in the tank. But when the weather warmed up, even though the aquarium was clean, she refused to respond.
|Big anemone, shut down, under the Powell River wharf, around noon on a hot day.|
For a while, I couldn't figure out what I was doing wrong. Everything was the same as last year, or wasn't it? No, it wasn't. Up until this winter, I had kept the tank (it's small) on the windowsill, jammed up against the open window, in the shade of the maple tree. It was the coolest spot in the house. But it was inconvenient; the window got splattered with salt water, and was difficult to clean; I couldn't see the backside without going outside. So I bought a sturdy little table and put it in front of the window. The tank is now there, about a foot from the outside. That little bit of distance was enough to raise the temperature in the tank a few degrees.
I bought an aquarium thermometer and discovered that at 70 °F, room temperature, she shut down. She prefers it below 65.
Not until I started adding icepacks to the water, replacing them several times a day, and keeping a fan a foot away, constantly blowing, did things improve. Now, I get up in the morning, check the anemone -- she's closing down, but not flat yet -- replace the ice pack, and watch her spread out her tentacles, fishing for breakfast. Repeat at noon, supper and bedtime. I"m glad the cool weather is finally upon us.
Next: shutting down, crab style.