Hot Tips: Critter Selection Tips

by | May 15, 2004 | 0 comments

A selection of useful tidbits of information for the aquarist. Readers are encouraged to send their tips to [email protected] or to post them to our Hot Tips sticky in the General Reefkeeping Discussion forum for possible publication. Next month’s Hot Tip theme will be “Live Rock Selection Tips“.


Critter Selection Tips

Don’t ever buy a skinny fish, (unless you are looking for a rescue project) look to the belly and the flesh behind the eyes, both should be full and meaty. That combined with actually seeing the fish eat, will help ensure a healthy transition to your tank.

— Laura D

When buying anemones, look for specimens that are not translucent, have a tight orifaces, sticky tentacles, and securely adhered to the substrate/glass.

— Len

One of the more important things to look at when purchasing any livestock is the condition, care, and appearance of the store’s tanks/systems, as well as the knowledge level of the employees/salepeople you’re dealing with. Chances are that if a system isn’t well kept, neither are the animals in it, and if the salesperson doesn’t know his stuff, you may end up w/ problems of compatability/suitability.

ALWAYS research BEFORE you buy.

— Vitz

Watch for heavy “breathing”; rapid movement of the gills. In some cases, this can just be some stress-related issue that the fish can often bounce back from fairly quickly. But if you see fish in a dealer tank that are all breathing hard or just trying to stay afloat in the stream of a powerhead or filter outlet, then be advised that such fish are suffering from poor water parameters or even internal diseases.

Color, obviously, can be a good indicator of health and nutrition. Ask to see a fish eat, and if it doesnt, and its colors look “washed out” or faint, and/or it has cavities or “depressions” in its body, then just plain dont buy, unless youre a long-long-long time aquarist and you have patience and spare time on your hands…

Lastly, corals and sessile inverts that look scraggely are scraggely. But, let it be said that corals are a lot like plants; you can cut them, bash them, make them suffer poor conditions, and even forget about them (Note: Do NOT let any of these things happen if you can help it or youre fragging a coral), and often times they will grow back, much in the same way a plant or fungus/simple plant-form/flora will. So, make a good decision and buy something that looks like it has life in it yet if you have the perfect conditions in which to nurse it back to health.

— DewrGleision

Research, research, research, research. It cant be stressed enough, the internet is a wonderous thing. If you see a critter in a petstore, online, or wherever and you just have to have it. Remember, it can wait. Be patient. Get the name of the critter and spend a few hours reading about him (or her) on the internet. Ive actually seen nudibranchs for sale in a petstore in a reeftank with corals and all for sale. But wait! there is are species of nudibranch that doesnt eat corals like the rest of them, this is exactly why you have to research. Dont take anyones word on anything. As the old tv commercial used to say… “look it up dear.”

— Tackett

When purchasing a tridacnid clam, it should be open but not gaping. It should react when you pass your hand over it to block the light. Its mantle should extend over the edge of the shell. It should not have tiny rice sized snails on the underside of the shell–look closely. If it’s attached to a rock, leave it on. If it must be removed, clip the threads with scissors as close to the rock as possible.

A lot of fish selection for me comes down to the behavior of the fish. The fish shouldn’t have any signs of disease, and it should be thick and not skinny, but besides that it should be behaving normally. It should be able to keep its position in the water, not be constantly hiding, hopefully (but not necessarily) eating prepared food, not darting around the tank, not trying to jump out of the tank, not swimming upside down (this is normal for some though!), etc.

— Matt_Wandell

Plan additions to your tank before getting to the store with cash in hand. Or even better, plan out the tank (with options) before adding anything.

Get some books, read online magazines/forums, ask advice, invite criticism, and develop a plan for the tank. First thing to figure out is what kind of tank you’re hoping to build. Do you want a predator tank? A biotope tank? A peaceful community tank? An SPS tank? Something else entirely? There are a lot of good reasons why you might not have an answer to this first question, but you should come to some decision before making any other decision as it will dictate just about everything else about your tank.

If all you want is a “reef tank” and you really can’t be more precise than that, then you want a community tank and the only question that remains is how much excitement (predation) you want going on in your tank. Me, I’m for peaceful cohabitation, but other reefers don’t seem to mind the possibility of having some excitement in their tanks. That excitement will almost certainly be measured in the loss of a few fish, so if that’s what you want, be aware of what you’re getting.

Once you’ve got a top-level goal for your system, other decisions become a lot easier. Presumably you’ve already got the tank running, so the size is fixed. Start asking and reading. What you’re looking for are ways to fit animals into your tank, much like putting pieces into a puzzle. You can’t put too many fish, or fish that require too much space in the small volume of a tank. You also probably don’t want to put fish that will agressively compete for the same territory or the same foods.

For my community tank, I wanted a few commensal relationships, so I decided on an anemone/clownfish pairand a shrimp goby/pistol shrimp pair. Both of these pairs tend to stay close to one location and close to the bottom of the tank, so if I put one on each end of the tank, they wouldn’t bother each other. This leaves the mid/high water region of the tank pretty much open. A small school of smaller chromis would be fairly peaceful, active, and tend to stay higher in the tank, out of the way of the clownfish and the goby. For a moderate tank size (up to 80 gallons), this is probably it (rule of thumb: 1″ fish/5gal water). For something bigger, maybe a royal gramma to live in the rocks or attempt to create some mating opportunities for the goby or the clownfish…

Now, note something about my plan. It isn’t too precise. My plan is not to pair a Stonogobiops yasha (whiteray goby) with a Alpheus randalli (pistol shrimp) and then to pair a Amphiprion ocellaris (false percula clownfish) with a Stichodactyla mertensii (carpet anemone) and then to add a school of Chromis vanderbilti (Vanderbilt’s chromis). That may be the most exotic and beautiful combination I could possibly go for, but it’s unlikely that I’m going to find exactly what I need in the timeframe that I need it. Patience is indeed the primary virtue of the aquarist, but I’m not waiting around six months for someone to get around to catching a few hard-to-catch chromis when other varieties are so commonly available.

You’ll still need to read up on all of the features of the animals you’re planning, otherwise you might not know to add the goby/shrimp pair first, followed by the anenome/clownfish pair, and then later, the school of chromis (in increasing order of activity so that each fish has the best chance of settling in). Also, you may find out other facts like mixing oceans (the royal gramma is Atlantic/Carribean, the others are Indo-Pacific) can increase the risk of disease in your tank…

So once you’ve got a stocking plan (the fish you want with the best timing to get each new arrival), the last piece of advice is to take your money in hand and go into the store with as much information as possible. Know exactly what the fish you want looks like (stores are rather famous for confidently attaching wildly inaccurate names to the fish they’re selling), if there are any similar-looking fish (and how to tell them apart), how this fish looks when healthy (usually meatier is better, though a bulging belly is almost always bad), and don’t accept last minute substitutes unless you’re sure the substitute is acceptable (I would accept a school of cyan chromis if someone had just bought all of the green chromis, but I would not be okay with a few blue damselfish, no matter how closely related they were to a chromis (LFS actually said this )).

Above all, be patient. If they don’t have what you want this week, someone will have it soon enough. Keep your money and spend it on your terms.

— Ross (aka “rabagley”)

Sometimes you see a critter you’ve just got to have, but the store just got it in that day or the day before. This happens to all of us now and then. Do you take it and hope it makes it? Do you wait and come back in a few days just hoping it will still be there after it has had a chance to acclimate? Decisions, decisions right? Maybe not.

Since it’s fairly common practice to have a quarantine tank, you can always take something home right away, but you run the risk of it dying on your dime, especially if it was a wild specimin and made a long trip before arriving.

Chances are if you have an established system, you are probably an established customer with your LFS. Most of the time, any good store wouldn’t sell something so new to their stock unless it came from a reliable or local source like a wholesaler they have dealt with for some time. If you are a fairly regular customer, most owners and managers will be happy to hold the animal for a while for a fair deposit. If you’re a frequent customer, its possible they may even hold it for free.

This arrangement allows you to “visit” your new critter to see if it’s maintaining a healthy appearance. It also gives the LFS the chance to get it on a regular feeding regimin with foods they use and sell ensuring greater chances for success in your system. For inverts, they will have a chance to adjust to a quality lighting set-up especially if collected in the wild.

If, on the chance the animal does not survive acclimation, or becomes ill, you can generally put your deposit towards other animals or items.

— J. Howard

Knowledge, patience and observation are the three commandments IMO…in other words: read, wait, and watch your critters!

— Ijkreef