Fish Best Left For Experienced Or Knowledgable Hobbyists:Finicky nature, parasite prone, specialty feeders, require specialty tanks, or threatened species
Anthias (family Anthiinae): Require a good amount of swimming room, peaceful tankmates, and frequent feedings, often unhealthy and starving by the time they make it to dealers tanks, some almost require special tanks with their needs in mind and others often refuse to eat and starve quickly in aquaria, do plenty of research before purchasing any Anthias
Teira Batfish (Platax teira): Can be very hardy once acclimated but there can be problems feeding, they stress easily, are disease prone, and will also outgrow most aquaria
Majestic, Blueface(Pomacanthus Euxiphipops spp.): Can be hardy once acclimated to aquarium life and eating well, that's often easier said than done though, larger juvenilles are often the best way to go with these fish as tiny specimens are quite fragile and large specimens have the hardest time adapting to aquarium life, this is true for many large angelfish
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
Bandit Angelfish (Holacanthus arcuatus aka Apolemichthys arcuatus): Very similar to the Rock Beauty above but with a much smaller sample, at their price you'll probably do your research, if you don't you'll most likely learn an expensive lesson
Bicolor Angelfish (Centropyge bicolor): Concerns with drugs used in collection and frequent unwillingness to accept prepared foods, also one of the more common coral nippers
Heralds's or Yellow Angelfish (Centropyge heraldi): Often collected with the use of drugs, be very wary of newly collected specimens, this can be true with many Centropyge but seems especially problematic here
Lemonpeel Angelfish (Centropyge flavissima): See Herald's angelfish above
Potter's Angelfish (Centropyge potteri): Mixed results with this one with a lot of mystery deaths early in captivity, if they've been eating and active at the fish store for a few weeks they usually end up being quite hardy
Golden Pygmy Angelfish (Centropyge aurantius): Adapts poorly to aquarium life, only attempt if you find a healthy specimen and have a larger reef aquarium containing less boisterous fish with a lot of rock to graze on
Swallowtail Angelfishes (Genicanthus spp.): Can be hardy once acclimated, but lots of problem specimens due to the depths they are collected at, take extra special care in examining and observing them before purchase
Angelfish in General (Centropyge, Chaetodontoplus, Apolemichthys, etc. spp.): Just a general note, Angelfish are among the more common fish collected using cyanide, so paying particularly close attention to their behavior and appearance before purchase is advised
Butterflyfishes (Chaetodon spp.): Very few are suited for a reef tank or a beginner hobbyist, do your research
Copperband Butterflyfish (Chelmon rostratus): Like the Regal Angelfish, this one has gone from nearly impossible to having some success with the popularity of them being kept in reef tanks, even then, longevity is questionable
Garibaldi Damselfish (Hypsypops rubicunda): Typically will not do well longterm in tropical conditions, if they do live long that cute little fish turns into a large territotial nightmare
Trunkfish, Boxfish, and Cowfish (various genera): Most are rather sensitive and can release toxins when stressed or dying
Clown/Gumdrop Gobies (Gobiodon spp.): Poor shipper, once established can be a good surviver with less boisterous fish, will nip "SPS" corals
Catalina gobies (Lythrypnus dalli): Not a tropical species and will not live long in the temperature of the average marine aquarium
Mandarin "Gobies" and Scooter "Blennies" aka Dragonets (family Callionymidae): Require large amounts of live food, quite often starve to death, providing larger tanks (50+ gallons) with large amounts of live rock and little competition for food has proved successful, do not treat with copper medications
Radiata Lionfish (Pterois radiata): Tough to acclimate to aquarium life and foods, more sensitive than others in the genus
Fu manchu Lionfish & Dwarf Zebra Lionfish (Dendrochirus spp.): All the dwarf Lions require tanks with their needs in mind, these two also seem very sensitive, very shy, are poor shippers, and can be particularly difficult to ween onto aquarium foods
Anglerfishes and Frogfishes (Order Lophiiformes/Antennariiformes): Most get very large and can consume fish nearly their own size, often will only consume live foods which is troublesome since feeder fish are rarely nutritious enough longtern
Achilles, Powder Brown, Powder Blue, and Gold Rim Tangs (Acanthurus spp.): Ich prone and fairly sensitive to water conditions, they also require large amounts of swimming room, very risky to consider one without quarantine
Bristletooth Tangs (Ctenochaetus spp.): Ich prone, some of the hardier tangs once established but can starve when detritus and algae aren't available in decent supply, so overly "clean" aquariums are not a good choice, the Chevron is probably the least hardy of the genus and can be particularly difficult
Seahorses, Seadragons, Pipefish (Family Syngnathidae): Need quiet species tanks and large quantities of nutritious live food, wild caught specimens ship poorly and have high mortality rates, tank raised seahorses are often already accepting prepared foods and are much better candidates for aquarium life, they still need a tank with their needs in mind though
Hawkfishes ( Family Cirrhitidae): Hardy fish but they are notorious jumpers, be very careful with ornamental shrimp, crabs, and small fish
Porcupine Pufferfish (Family Diodontidae): Can be hardy but some are very disease and parasite prone, most require large fish only aquariums
Fairy and Flasher Wrasses (Paracheilinus and Cirrilabrus spp.): Require peaceful tankmates and do best in reef aquariums, they stress easily and the first few weeks in captivity will often make or break their longevity, known jumpers
Lawnmower Blenny (Salarias fasciatus): Will sometimes not accept prepared foods and will starve to death in tanks without a natural algae food source
Diamond, Golden Head, Sleeper Gobies (Valenciennea spp.): Sometimes starve to death even when accepting prepared foods, tanks with large sandbeds containing lots of food will help as will frequent feedings when they will eat, mated pairs may help as well
Courtjester/Rainford's and Hector's Goby (Amblygobius spp.): Often will not accept prepared foods, need established tanks with a fine sandbed full of life
Fourline Cleaner Wrasse (Larabicus quadrilineatus): A cleaner when small, but are coralivores as they enter adulthood so are not good reef aquarium inhabitants, some of the Tubelip Wrasses are know for a similar behavior and rarely live long in captivity
Cephalopods, Octopi, Cuttlefish, Squid (Class Cephalopoda): Not fish, but including them here because of their intelligence compared to the dumb lumps of goo that are most invertebrates, the Nautilus from above is in this group as well, these must have species tanks and require a lot of research before attempting them
