Crustaceans and You...[an FYI]: that's crabs, shrimp, etc.

[Sk8r]

...lobsters, etc.

I can at least give some rules of thumb...

THEY MUST BE ACCLIMATED. Things with shells [including gastropods [snails] must be salt-balanced. They can't sweat. Their exchange of water is very slow because of that shell. Even more than fish, they must be acclimated to within .001 salinity, or they will die within a few days. They are also particularly vulnerable if you have a freshwater flood or salinity accident with your tank. Your fish and corals might survive: you may well lose your inverts.

1. most hitchhiking crustaceans are not good. If you get a chance to get it out, put it in the sump and ask in the Invertebrate Forum for an id and recommendtion.

2. the only reefsafe crabs are: the emerald mithrax, said [not by me] to eat bubble algae; the pompom crab [no claws]; filter feeding crabs in general: no claws; porcelain crabs; and certain anemone and acro crabs; and micro-hermits including scarlets.

A micro hermit tends to be dark, the size of an English pea in the body, and never larger. It favors Cerith snail shells. If you provide enough spare shells they are well behaved.
Scarlets take somewhat larger shells, often those of fighting conches, and can go after those---but a healthy fighting conch will throw it like a bucking bull, so small hope for the crab there. Scarlets actually will [to my observation] eat bubble algae, but not enough to matter.
Micros and scarlets both will climb on corals. THey don't seem to harm the coral. They WILL go after a pointy snail that has gotten out on the sand and fallen over [they do] and WILL eat it if nobody rights it before it goes comatose and quits trying to move. IMHO that's the tank owner's fault, because the snail is dying at that point and crabs are undertakers. Good ones.
If you lose a fish, crabs and bristleworms ARE your friends, imho. Especially if it's where you can't reach it.

Crustaceans are notably sensitive to low iodine: best to keep up your water changes and this will not be an issue.

3. shrimp.
Dangerous shrimp: the coral banded shrimp---will go after small fish.
Camel shrimp: sometimes sold accidentally as peppermints. ALso bad habits.
'Safe' shrimp: peppermints---will eat aiptasia, especially as juveniles. May nab a coral polyp or two or pester xenia. THis behavior usually lasts an hour or two and never repeats. They seem to try and then 'learn' that it's not profitable or good to eat. Xenia may smell a bit like aiptasia. And they WILL eat yellow star polyps, so might be a little iffy with some zoas.
Cleaner shrimp---colorful, interesting behavior, but not in too small a tank. Cleaners can overdo it and make your fish a little sore, imho. Make sure the cleaner's station isn't the whole darn tank---ie, the tank is big enough the fish has some chance to go away.
I usually run about 5 peps in my reef, and they're a hoot, always out, if no large fish are about.

Mantises are best kept in 'species' tanks, with nothing else. They will kill fish. If you hear a really loud snapping sound from your rock, you might have a mantis hitchhiker. Ask in the Mantis forum for some help.

Pistol shrimp are quieter citizens, and the tiger pistol combines well with the yellow watchman; Randalls is reef-safe; candycanes with the high fin gobies. They move sand and burrow, rarely snap, are generally fun to watch if you don't mind your sand rearranged frequently. I have a ywg/tiger combo as the centerpiece of my 54 and they're a hoot to watch. You have to sit still or the pistol will dive for cover and not come out quickly. Never have figured out what he eats, but he's thriving.

Certain shrimp prey on urchins and starfish: the tiny, horse-fly sized bumblebees have the body of a horsefly, the stripes of a bee, and the tail of a dolphin. They're cute. They don't really seem to do more than annoy an urchin. They might damage asterinas.
Harlequin shrimp are somewhat larger and more serious urchin predators.
I'm not sure about sexy shrimp: they look a lot like the harlequin and are not large.

4. lobsters. They sell a purple lobster---I'm not sure about its reef-safeness, which means only it's not supposed to eat most corals. In general, lobsters are too hungry to live amicably in a reef, and are not good citizens. I reserve judgement on the purple, pending more info.
If you want something that's much smaller and looks like a lobster with red/white stripes, go for the tiger pistol shrimp.

HTH guys. More and better info always welcome, anecdotes always helpful.

[jubjub]

sk8r......i always make an effort to read your posts...always very informative...keep up the good word....its really helped me starting to setup my tank

[cilyjr]

i had a purple lobster for about a year. i blamed him for the disappearance of my peppermint shrimp. i removed him to the sump and later gave him to a friend. i found out later that it was my wrasse that was responsible for the shrimp disappearance. he did snip at a purple firefish that was sharing its den. the fish had a small chunk out of its back. it moved to a new den and healed up. i would not get another lobster based on that experience.

[Sk8r]

It's my own experience that things with claws tend to use them, and the bigger the claws the more problem when they do.

My lobsterlike tiger pistol has very tiny claws, for his size...I'm surprised when I get a clear look at him, because he's getting to be quite substantial; and those snapping claws---just aren't that big. I do have a suspicious rip in my mandy's tail, but nothing that won't heal fast, and she is a pest about going exactly where she likes, through territories, oblivious. I can't fault the shrimp for trying to put her out of his carefully crafted trench---since she's not really harmed. But when those claws get big enough to cause real damage, I'll view it much less favorably. I think he's maxing out on growth. I hope so. I don't NEED a lobster.

Note: I did just look up their adult size---something I should have done before putting him in the tank, dear friends, but I'm lucky: his max adult size is 3". So he will not get large enough to pose a problem. He is already 2-inch-ish. 3-4" is the max size for the yellow watchman he pairs with, so it's a well-made match.

[scrmbld33]

SK8TR love your posts!!!!! keep up the good work!!!!!! can you do one one dripping kalk and kalk reactors a how too?

[ReefEnabler]

Sk8r, great post.

I'd really like to emphasize what you said about acclimating inverts though, here's why....

last week I went to the LFS to just get some turbo snails to clean some algae out of my 20G quarantine (aka my only tank as of yet , but also picked up a cleaner shrimp.

The LFS uses a salnity of ~1.023, and my salnity is ~1.026, so I knew a long acclimation was in order.

I drip acclimated him for about 40 minutes before putting him in the tank (temperatures matched after), and he was dead within 15 minutes of being placed in my tank. I should have acclimated for at least an hour. next time I will do an hour and a half

Tank params:
pH: 7.9 (yes a bit low, I need to add some kalk)
amm: 0
nitrite: 0
nitriate: 5ppm
calcium: ~380ppm
dKH: 11dKH
Salinity: 1.026
Temp: 80F

Does it sound like acclimation was my problem, or does low pH also seem likely? The PH used to be 8.0 but has dropped over the past 2 weeks and I don't have any kalk yet. Will pick some up after I get back home (yes, I'm RCing from christmas vacation )

[Diver4life]

Thanks Sk8r, I always learn something new with your posts, keep the good work.

[Sk8r]

Re that acclimation: I'd say test ph in bag and in tank---just in case. PH tends to change radically after bag is opened, and it is another acclimation factor...though not usually as bad as salinity.

That's so sad: I'm sorry you lost them. Long acclimations are a big problem...because of the ph thing. If you have problems, you might set up a halfway house of a qt tank aimed at the salinity of your lfs, and gradually bring it to even salinity of your tank over a number of hours. The problem is the bag water, which tends to have built up some poo problems as well as everything chemical. If you had a place where you could just lift them out and put them over with minimal acclimation, just a little fast acclimation for alkalinity [another good test to run] it would go better.

And thank you for the kind words, guys. Everybody tends to believe inverts are exempt from acclimation---but they are, really, among the touchiest.

[Sk8r]

Re dripping kalk and reactors---I will try to have something soon. Right now I am really upset with my reactor-stirrer, and am trying a new design. If this thing works [involving eggcrate, two pumps, Mrs. Wages, and a bucket] I will try to explain it.