Difficult and Special Care Species List

[67chevellemalibu2]

According to this op’s list. None of us should have a tank.

 

[atoll]

C.multifaciatus (multibar angel) is far from diffucult IME my self and others have kept this species with no issues once acclimatised. The secret is to get a good specimen to start off with and let it settle in providing a varied diet with compatible tank mates.

 

[kristinarenee]

My diamond goby has survived a year now and is pretty fat. He gets spot fed by my coral feeder but only when needed. My female percula clown is the meanest clownfish I have had. she chased a damsel until it jumped out of the tank. My Maroon was nice. I think some of these on the list is really environment and chance. Just like people you never know what your gonna get. Everyone's different including fish.

 

[Fastpitch]

According to this op’s list. None of us should have a tank.

Exactly

 

[vetteguy53081]

Fish That Require Huge Aquariums (200 gallons or more):


Cartilaginous Fishes (Sharks, Rays, Skates): Require tanks much larger than 200 gal. and should just be left out of home aquaria, Nurse sharks can grow to 14ft. long!, repeating this one so it sinks in

Groupers & Seabass (various genera): Especially take note of the cute little Panther Groupers commonly offered in the trade as they can attain over 2' in length

Snappers (Family Lutjanidae): Those little Red Emperor Snappers seen in the trade get over 3' long

Unicorn Tangs (Naso spp.): They will even outgrow common size aquariums such as 125 gal. and 180 gal.

Moray Eels (Family Muraenidae): Do your research as many are not suitable for home aquariums

Squirrel and Soldierfish (Family Holocentridae): Some of these are borderline, do your research

Batfish and Spadefish (Family Ephippidae): Probably best left to public aquaria

Twinspot Wrasse (Coris aygula): Take special note of this one as they're often offered as small attractive juveniles, they get very large and very mean, up to 4' long

Red Coris Wrasse (Coris gaimard & Coris frerei): Sold as tiny juvenilles they can grow up to be 2' beasts, beware the size of most Coris wrasses, though the common Yellow Coris Wrasse is actually a smaller fish from not in the genus Coris but belonging to the genus Halichoeres

Dragon Wrasse (Novaculichthys taeniourus): Offered as very small juvenilles they grow to be about a foot long and are known to flip aquarium decorations and rocks when adults

Flounder (Paralichthys spp.): Rarely suitable for aquarium life, also becoming increasingly rare due to overfishing as a food fish

Tassled filefish (Chaetoderma pencilligera): Often offered when cute and tiny but grow quite large

Angelfish (various genera): When purchasing any angelfish that isn't Centropyge be sure to check their ultimate size, take special note of the French, Gray, Blue, and Queen which are often offered as small juvenilles ang will outgrow most aquariums

Triggerfish (various genera): Most will be fine in large aquariums of around 100 gallons, but there are a few that would be unsuitable for all but the largest home aquariums, do research on their ultimate size and temprament before a purchase is made







Venomous and/or Toxic Species:


Stonefishes (Synanceia spp.): Believed to be the most venomous fish in the world

Scorpionfishes/Rockfishes (various genera): Rhinopias has gained in popularity recently

Toadfish (family Batrachoididae)

Lionfish (various genera)

Rabbitfishes/Foxfaces (Siganus and a sub-genus Lo)

Coral Catfish (Plotosus lineatus): These also get up to a foot long and become more solitary as they grow

Blue Ring Octopus (Hapalochlaena spp.)

Fang Blennies (Meiacanthus spp.): Venomous bites that can be painful

Flower Urchins (Toxopneustes pileolus): Rare in the trade, but outside the trade there are reported deaths from this species

Black Longspined Sea Urchins (Diadema spp.): Can inflict painful wounds, some debate exists whether or not they are really venomous, but it's wise to handle all urchins with care

Cone Shells (Conus spp.): Rarely encountered in the aquarium trade, can be deadly

Stingrays (familly Dasyatidae): Many have venom associated with the spike on the tail which they use in self defense, fatalities are very rare

Sea Snakes (various genera): I know you're not going to try to add one to your reef aquarium, but included for good measure

Box Jellyfish (Chironex fleckeri): Quite deadly but of no concern to aquarists

Hell's Fire Anemone (family Actinodendronidae): While all anemones are capable of stinging, this is the one of the few to be concerned about, very painful stings

Hydroids: usually just cause skin irritation if anything

Fire Coral (Millepora spp.): See hydroids

Sea Mat, Button Polyps, Zoanthids (family Zoanthidae): Some of these can contain Palytoxin which can be quite dangerous, they're quite frequently harmless but if you want to err on the side of caution rubber gloves are a good idea when handling them, as are goggles when fragging them







Extremely Aggressive Species:


Undulated Triggerfish (Balistapus undulatus): Perhaps the meanest aquarium fish available and one to avoid unless you don't mind having a large aquarium with one fish

Queen Triggerfish (Balistes vetula): Not quite as bad as the Undulated, but pretty close and what they lack by comparison in aggression they more than make up for in size

Clown Triggerfish (Balistoides conspicillum): Pretty similar in demeanor to the above two

Blueline Triggerfish (Pseudobalistes fuscus): Not so bad when young, but a beast once it grows, probably the least aggressive of the four triggers mentioned

Passer Angelfish (Holacanthus passer): Probably the meanest of all Angelfish, some of the larger Angels may look like delicate beauties, but some can be quite aggressive

Damselfish (family Pomacentridae): They're not all bad, but ounce for ounce some of them are the meanest fish around, think long and hard about adding them as some of your first specimens

Maroon Clownfish (Premnas biaculeatus): Females get quite large and they can take over medium size tanks, they're also probably the least tolerant of other clown species

Sohal Tang (Acanthurus sohal): Much hardier than the Clown Tang but just about as mean, probably best to keep them as the lone Tang, and if you must keep one in a community reef tank make it your last fish addition

Bicolor Pseudochromis (Pseudochromis paccagnellae) A lot of Pseudochromis get a bad wrap, but this isn't one of those cases, very nasty fish, P. porphyreus, P. diadema, and P. aldabraensis are others to be weary of







Special Notes:


Clownfish (Amphiprion spp.): Various species often acclimate poorly to aquarium life and suffer greatly from collection stress, I've seen estimates that as little as five percent of those collected live to be in home aquaria, when possible buy tank raised specimens

Bangaii/Borneo Cardinals (Pterapogon kauderrni): Rather limited in range and rumors of an unsustainable population if the current rate of collection continues, there are also stories of poor survival after collection, buy tank raised when possible

Tangs (various genera) Should have larger aquaria to provide them with plenty of swimming room, no a tang is not suitable for your nano or 29 gallon tank, when small 3'-4' aquariums can be suitable for short periods of time or smaller species, though bigger is recommended by many

Angelfish (various genera): Their compatibility with corals and clams is often brought up and debated, outside of Geniacanthus there really is no such thing as a "reef safe" Angelfish and even those have the odd exception, before purchasing one consider how difficult one would be to catch out of your display tank after it decides your corals and favorite clam are delicious, they can be model citizens but there is always a risk associated in reef aquariums

FANTASTIC LIST AND WHILE SOME EXPERIENCED REEFERS CAN KEEP THE IMPOSSIBLE, SOME CAN CHALLENGE THE MOST EXPERIENCED REEFERS !!

 

[Ike]

Exactly

Unfortunately, too many people put inhabitants in aquariums without caring about their specific needs or longterm requirements. In years past this was a bigger problem than it is now, but it's still a very real problem in this hobby, and a continued the lack of regard for the things we take from the ocean and keep in our aquariums only further damages our hobby and may lead to those that take a more conscientious approach being punished.

It's a list of basic information and guidelines that you can apply as you see fit. The list was originally compiled many years ago to hopefully save some frustration for people that wanted to choose hardy and sustainable livestock and to help save the lives of some fish/animals. There are thousands of species that aren't on the list and adapt well to home aquarium or are on the list and just need a little extra care. A few of them have changed over the years as collection practices, equipment, and husbandry practices have improved, but overall I feel the list remains accurate. If you're not conservation minded and/or get a thrill from keeping really difficult to care for fish and don't want to go to extra lengths to give them the proper environment, this list isn't for you.

 

[Ike]

C.multifaciatus (multibar angel) is far from diffucult IME my self and others have kept this species with no issues once acclimatised. The secret is to get a good specimen to start off with and let it settle in providing a varied diet with compatible tank mates.

They're not nearly as common in the hobby as they used to be, and collection practices were probably a large factor in the past. However, I would be surprised if a significant percentage of them survives beyond a month after collected. Cool fish, but it seems they're still reliant on very careful selection and acclimation to aquarium life.

My diamond goby has survived a year now and is pretty fat. He gets spot fed by my coral feeder but only when needed. My female percula clown is the meanest clownfish I have had. she chased a damsel until it jumped out of the tank. My Maroon was nice. I think some of these on the list is really environment and chance. Just like people you never know what your gonna get. Everyone's different including fish.

Many of the things on the list will do very well if they have an environment suited to them and the aquarist goes to extra lengths to ensure their longterm wellbeing. These fish often slowly starve to death without a plentiful natural food source, and it can take quite a while. They are also often bothersome because they like to dump sand all over corals. Certainly not impossible to keep, but the percentage of aquariums that are well suited for them is very low.

Lastly, people in the hobby used to say "the fish don't read the books", well they don't read the forums or my list either. There will always be exceptions, like mandarins that eat pellets, or friendly maroon clowns. However, just because there are exceptions doesn't mean there aren't typical behaviors within a species that shouldn't at least be considered when purchasing a new inhabitant for your aquarium.

Good luck with your diamond goby and keep us updated on how he does!

 

[jx fang]

True about the diamond goby, not easy longterm.
They are easy in the beginning, it takes care of himself.
Kept my sand always clean.
I have mine 3 years now.
First 1.5 year, he is fat and healthy.
Suddenly one day I saw him to be very skinny.
Then I got concerned he will die very soon.
I start feeding heavier, make sure more food sinked to the sandbed.
Be able to keep him alive, still a bit skinny compare to other fishes in the tank.
Nitrate when from 10 to 25, and stayed at 25 consistantly.

 

[Ike]

True about the diamond goby, not easy longterm.
They are easy in the beginning, it takes care of himself.
Kept my sand always clean.
I have mine 3 years now.
First 1.5 year, he is fat and healthy.
Suddenly one day I saw him to be very skinny.
Then I got concerned he will die very soon.
I start feeding heavier, make sure more food sinked to the sandbed.
Be able to keep him alive, still a bit skinny compare to other fishes in the tank.
Nitrate when from 10 to 25, and stayed at 25 consistantly.

Good luck! I bet there aren't a whole lot of people that have made it to year four with one of these.

 

[YeetReef]

Orange Spotted Filefish (Oxymonacanthus longirostris): Specialized coral polyp feeder and almost never accepts prepared foods
Aha how times have developed
i have a pair of orange-spotted filefish got them recently and they started to eat like pigs when frozen food is present maybe i got a lucky pair. have eaten a little of my sps tho

 

[vetteguy53081]

Cowfish and clown sweetlips

 

[Blanka]

Awesome thread! I really needed this.

 

[jay2525]

I don't really understand people needing to find a way to disagree with this general list. It's very helpful and at worst mostly true. It seems most of the recommendations don't apply to the super reefers that have come here to prove otherwise. its weird

 

[MnFish1]

I don't really understand people needing to find a way to disagree with this general list. It's very helpful and at worst mostly true. It seems most of the recommendations don't apply to the super reefers that have come here to prove otherwise. its weird

It then - might be good to have a list of fish that are 'easy to keep'. Not as a critique of this list - but - people have problems keeping 'easy to keep' fish as well. Many of the fish here - I have not had a 'hard time 'keeping - but - if you're going to ask - how long? Maybe less than their natural lives. So- what is the definition. I have had multiple diamond gobies for 5+ years (well at least 3). As one person said - if we were to take each recommendation - no one would have any fish.

 

[ThRoewer]

Was Fairy gobies mentioned? IMO tryssogobius Colinis (blue eye darts from I think Okinawa Japan) are one of the most difficult fish to keep in captivity long term.

Most die from transportation alone. 1” Max and probably better with multiples. Similar to Firefish, will usually pick off of one another. Picky eaters, difficult to train, and requires several feedings per day.

Tiny fish, and especially many small gobies, are often very short-lived which would account for not being able to keep them long term. There are some that live only 2 to 3 months, and half of that as a larva.
Eviota sigillata for example only lives 8 weeks with an adult lifespan of just three and a half weeks.
Trimma nasa lives only a little longer with 87 days, around 34 days of that as a pelagic larva.

 

[ThRoewer]

"Multi-Barred Angelfish (Centropyge multifasciatus): They don't adapt to aquarium life well, rarely eat, and are very secretive, though not fatal, they also seem particularly prone to Lymphocystis"
and
Regal Angelfish (Pygoplites diacanthus): A problem feeder, specimens from the Philippines and Indonesia rarely make it long in captivity, Red Sea Specimens tend to be hardier and more willing to accept prepared foods partially due to collection and holding techniques, the more recent trend to keep this fish in reef aquariums helps with survivability.

Not in my experience, I am not suggesting they are easy but if you get one that has been taken care of when collected, held well before shipping and is a youngish specimen then you have a very good chance of succeeding with them as I have.



Cleaner Wrasses (Labroides spp.): Specialized parasite feeders that rarely live long in captivity, leave them in the ocean where they can do their job.
Again as with the above, I have had one for 6 months doing very well.

Totally agree!
I'm having a problem with the generality of some of those statements about difficulty.

Regal Angels are certainly not a beginner fish or a fish for someone who isn't willing to make sacrifices for it, but also not a particularly difficult species if you know what to watch for and how to cater to its needs.

IME, the trick is to get juveniles or transitioning specimen below 4 inches that still have at least part of their eye-spot. Large adults are best left in the ocean.
Watch that they show at least interest in food at the store. Better is to only take individuals that eat or at least pick on things. It also helps to give them a quarantine/acclimatization buddy to teach them to eat.

I usually get them to eat even flakes without much trickery.
This is not a specialized or picky eater but a fish that is often just handled badly on the way to us or got caught with cyanide (Indonesia and, in the past, Philippines). On the Maldives, in the wild, they will eat white bread out of your hand.

Here is my little Philippines Regal competing with Maroons for flakes:



My latest Maldive Regal female decimating flakes while in quarantine:



My by now oldest Maldives Regal days after I got him as a 2" baby in 2016, eating Mysis:



And this is him now with the new female:



And this isn't something "recent" - I kept my first Philippines Regal pair almost 30 years ago.

I actually have more trouble getting my percula to eat enough after they lost their anemone.

 

[NashobaTek]

Fish To Be Avoided::Fish that have incredibly low survivability in aquaria or are totally unsuitable for home aquaria


Moorish Idol (Zanclus cornutus): A few success stories, but miniscule amounts live long, difficult feeder, mystery deaths, and even when accepting prepared foods often slowly starve

Rock Beauty Angelfish (Holacanthus tricolor): Nearly impossible to meet the dietary needs in home aquaria

Multi-Barred Angelfish (Centropyge multifasciatus): They don't adapt to aquarium life well, rarely eat, and are very secretive, though not fatal, they also seem particularly prone to Lymphocystis

Venustus Angelfish (Centropyge venustus): See the Multi-Barred Angelfish above

Butterflyfishes (Chaetodon spp.): Many problem feeders in the group and most are corallivore that are almost guaranteed to starve to death in aquaria, do a lot of research before purchasing any butterflyfish

Clown Tang (Acanthurus lineatus): VERY ich prone and a finicky eater, horrible survival rates, when they do live they are terribly aggressive and often take over a tank

Twinspot Goby (Signogobius ocellatus): Terrible survival rates in captivity, rarely accept prepared foods or survive long even when they do

Clown Sweetlips (Plectorhinchus chaetodonoides): Difficult feeders and rarely adapt to aquarium life, should you manage to get one to live they get quite large

Oriental Sweetlips (Plectorhinchus orientalis): See Clown Sweetlips, in general this can be repeated for most species in the genus Diagramma and Plectorhinchus

Pinnatus Batfish (Platax pinnatus): Gorgeous fish when young, very very few success stories, diet, disease, and stress from aquarium life are big issues

Tiger Tiera Batfish (Platax batavianus): See Pinnatus Batfish above

Orange Spotted Filefish (Oxymonacanthus longirostris): Specialized coral polyp feeder and almost never accepts prepared foods

Ribbon Eel (Rhinomuraena quaesita): Rarely eat in captivity and are excellent escape artists

Snake Eels & Garden Eels (various genera): Difficult feeders that require specialty tanks

Cleaner Wrasses (Labroides spp.): Specialized parasite feeders that rarely live long in captivity, leave them in the ocean where they can do their job

Tamarin Wrasses (Anampses spp.): Very poor shippers and need tanks with their special needs in mind, even then they often starve to death, their best chance is often a large established reef aquarium with large amounts of live rock, peaceful fish, and something to prevent their escape from jumping

Leopard Wrasses (Macropharyngodon spp.): See Tamarin Wrasses above, but there are more success stories, both these and the Anampses are boderline being in this area of the list and the next section

Pencil Wrasses (Pseodojuloides spp.): Very sensitive, they almost always die in transit so you don't see them very often if ever in the trade

Parrotfishes (Family Scaridae): Very specialized feeders on mostly dead (some live) coral skeletons and the algae and organisms associated with them, they adapt poorly to aquarium life in almost all regards

Tilefishes (Family Malacanthidae): VERY timid and must be kept in a covered aquarium with lots of space and docile tankmates, in general they just don't adapt to aquarium life

Cartilaginous Fishes (Sharks, Rays, Skates): With very few exceptions, unless you own a massive aquarium that is several hundred gallons stay away

Grunts (Family Haemulidae): Rarely adapt well to aquarium life and should probably only be considered in a large species tank

Jacks (Family Carangidae): See Grunts above

Drums (Family Sciaenidae): Poor shippers, being very shy and fragile they rarely live long after being collected

Trumpetfish (Aulostomus spp.): Too large and too specialized for 99.9% of the aquarists out there, also poor shippers

Remoras (Family Echeneidae): Unless you have a large Shark or Whale in your backyard oceanarium it's probably best to stay away

Leopard Blenny (Exallias brevis): Specialized coral feeders that rarely live long in captivity

Chambered Nautilus (Nautilus pompilius): Though technically not a fish, there are a plethora of reasons to leave them in the ocean, simply not suited for typical aquarium life

There are now captive bred pinnatus batfish and easier to keep. I did a lot of research and found that brine shrimp for first foods and than grated shrimp. My pinnatus is doing great. Has gone from 1" to 7" over the course of the year. Still shows juvenile colors.

 

[Ike]

There are now captive bred pinnatus batfish and easier to keep. I did a lot of research and found that brine shrimp for first foods and than grated shrimp. My pinnatus is doing great. Has gone from 1" to 7" over the course of the year. Still shows juvenile colors.

Yeah, it's been a nice thing to see. Not many people with tanks big enough. This is one of the fish that led me to the hobby.

 

[Zionas]

When it comes to butterflies is OP specifically referring to some species within the Chaetodon genus or all butterflies in general? What about angelfish?

 

[Ike]

When it comes to butterflies is OP specifically referring to some species within the Chaetodon genus or all butterflies in general? What about angelfish?

It was just a general warning for anyone not familiar with various butterflies and how many specialist feeders there are within the genus that won't survive well in captivity. Angelfish I feel there aren't so many hurdles and problematic fish, but definitely a family worth researching each species well before purchasing more so than many other fish.

The original sentiment behind this list was to prevent unnecessary death, not all deaths. Think of this list as mitigation for lessening the hobby's impact on the fish we love. Also keep in mind that this list was compiled a long long time ago, it was actually used in an article by a well known author around the year 2000. I've edited and modified it through the years as the hobby and out understanding of fish and corals has evolved, but it's probably overdue for some more refinement. For instance, Anampses wrasses still seem to struggle with collection stress and handling issues and have low survival rates, but if you get a good specimen in the right environment they're super hardy.

However, when this list was compiled those survival rates were dismal; 9 in 10 probably died before they even made it to a person's tank. Them being on the list now serves to just inform people that they're more sensitive and you better know what you're doing, or it probably won't go well.