[cofstl411]

I am about to add a scarlet skunk cleaner shrimp to my tank. I just wanted to be sure that it will be ok with a camel shrimp and an arrow crab. I also added a sand sifting starfish. I have not read anything that says there will be conflicts but I wanted to ask you guys just to be sure.

[Ninong]

The sand sifting starfish needs lots of sand bed because it feeds on the microcrustaceans and worms in the sand. They are fine in really large tanks (>375-gal) but they don't do as well in smaller tanks and they can cause too much predation in your sand bed in a smaller tank.

The scarlet skunk cleaner shrimp are excellent additions to any reef tank.

The camel shrimp is not a good idea in a reef tank because they do eat coral polyps.

The arrow crab is a very risky idea because they are predatory on other crustaceans, small fish and some corals.

P.S. -- If you run a search using "arrow" or "camel" you will find previous threads that discussed these animals.

[cofstl411]

I did the search on the arrow crabs, sand sifting starfish and camel shrimp. I am going to take the arrow crab out and try to give him back to the LFS. I have the starfish in the open bag floating in my tank and I am not going to release him. I actually wanted a serpent starfish but then got mixed up on the names when I was at the LFS. I asked if it would be ok in my tank and they said no problem because it will only eat stuff off of the bottom of my tank. I took that to mean fish waste not all living organisms. I did release my cleaner shrimp. He is about twice the size of my camel shrimp and they got into a scuffle. I did not read anywhere that mentioned an arrow crab eating my cleaner shrimp only that he may eat other crustaceans. I am not sure if he is one of the crustaceans that he may eat.

[Ninong]

Arrow crabs definitely eat cleaner shrimp. There are several reports of that happening on Reef Central. I just ran a search there using "arrow" and turned up too many hits (1404), so I reran it searching for "arrow" in titles only and got 83 hits. Most of the people who used the word "arrow" in their title were talking about problems they were having with their new arrow crab eating something they paid good money for. The list of victims was longer than I expected.

[cofstl411]

He is out now. A net is about useless in an aquarium with LR. I have him in a large glass but I will not be able to do anything with him until tomorrow. I also have my starfish in an open bag. I was going to combine them into a large bowl with a lid to transport them to my LFS. That is if they are willing to take them. I am sure they will not give me my money back but it won't hurt to try. I feel better now that he is out of my tank. I think he ate my firefish a day after I got him home. I really liked that fish too! This is an expensive learning lesson but it will help me in the future.

[Ninong]

The arrow crab is just another example of how the vendors deliberately mislead their customers. Let's take a look at Drs. Foster & Smith for example: http://www.liveaquaria.com/product/p...cfm?pCatId=616

According to the good doctors:

Reef Compatible: Yes
Diet: Carnivore


Notice that they didn't say anything about it being "reef-aquarium compatible." It is "reef-safe," it's just not "reef-aquarium safe." It's perfectly compatible if left on the reef.

They do mention that it is a "carnivore" without explaining that item in detail. No need to give out too much information, especially if it would affect sales.

It is a hardy, long-lived invertebrate, that can be housed in the reef aquarium.

They're not saying it "should be" housed in a reef aquarium, only that it "can be" if you're willing to risk it.

Large specimens may attack small slow moving fish.

True! And they may attack other crabs and shrimp, xenia, zooanthids, etc., etc.

This is typical of their comments. They are constantly claiming that certain animals are "reef compatible" even though those animals are known predators on other animals that are typically kept in reef aquariums.

P.S. -- I can't remember exactly which fish they gave this cryptic warning about but they claimed that it was "safe with native corals." It turns out that it does eat certain corals, but not those that are found in its own native habitat. For that fish to be considered "reef compatible," your reef tank would have to be a biotope specific tank that duplicated the fish's natural environment because it is a well known predator on certain other corals as many unlucky aquarists learned to their dismay.

[tatuvaaj]

Originally Posted by Ninong

Reef Compatible: Yes
Diet: Carnivore.

Ah, my favourite subject! What does reef safe (or compatible) mean? I've lately tried to introduce term "coral aquarium" because a lot of people seem to think that "reef safe" means the animal does not eat stony corals. It is very different and much more difficult to try to maintain reef aquarium than a coral aquarium.

If you want a truly "reef safe" animal, your options are limited. And even then, someone might consider (rightly!) algae as a part of healthy reef aquarium in which case even the "Turbo snails" could not be reef safe

[Ninong]

Originally Posted by tatuvaaj

What does reef safe (or compatible) mean? I've lately tried to introduce term "coral aquarium" because a lot of people seem to think that "reef safe" means the animal does not eat stony corals.

In the case of many vendors, reef-safe or reef-compatible simply means that the animal is safe to leave on the reef. By their definition only the crown of thorns might be considered unsafe to add to a reef aquarium.

In the hobby, there are two schools of thought on what reef-safe should mean. Some people seem to think it simply means that the animal will not harm corals. I prefer to use it to mean that the animal will not harm corals or anything else that we usually keep in reef aquariums, which is why I have started using "reef-aquarium safe" instead of just plain old reef-safe. I have a feeling most people do not agree with my rather broad definition.

By my definition, harlequin shrimp would not be considered reef-aquarium safe because they eat sea stars. They don't eat anything else, just sea stars. But since most of us like to keep a sea star or two in our reef aquariums, harlequin shrimp would be an unwise addition, to say nothing of the special feeding requirements. The same applies to all of the fish that eat ornamental shrimp and/or snails.

I realize that most people consider my definition to be overly broad, so whenever I'm talking about something like a harlequin tusk fish that will not harm your corals but will eat your clean-up crew, I usually spell it out.