Love of Fish

selecting fish

There is an astounding variety of fishes that an aquarium keeper can enjoy, even as a beginner. Learn about the different fishes and fish-families below to see which ones you want to enjoy in your aquarium, and then read some pointed and specific guidelines to help you decide. Hovering your mouse over a picture will make it expand in most browsers.

tetra
Fish	Picture	Description
Tetras are a small (1"-3") freshwater, tropical fish from South America. They are inexpensive, available in many colors and extremely hardy. They are schooling fish and should be kept in groups of 5 or more. Their pH range is wide, at 6.5-8.5. They are difficult to breed by the first-time fishkeeper. They eat normal flakes but love the occassional brine shrimp treat. Surprisingly for such peaceloving fish, they are members of the Characin family - along with the piranhas.
Silvertip Tetra Hasemania melanura		A relatively small (1"-1.5"), but very active tetra. Their activity can make slower fish nervous. Males tend to have a golden hue, while the females are paler.
Neon Tetra Paracheirodon innesi		Beautiful, small (1"-1.5") and prefer acidic water (pH 5.5-7.0). Females have a slightly larger belly than males. Iridescent coloring fades when stressed. Vulnerable to the deadly Neon Tetra Disease.
Black Skirt Tetra Gymnocorymbus ternetzi		Also known as the Black Tetra or Black Widow Tetra. A superb beginner fish. Females are larger, and rounder, than males. The White Skirt or Golden Skirt Tetra is just an albino version of this fish.
Lemon Tetra Hyphessobrycon pulchripinnis		Preferring acidic water (pH 6.0-7.5), they can be among the more aggressive tetras, and are known to nip the fins of other tetra tankmates. The upper eye white is deep red in color - loss of color indicates distress or disease. The black border of the fin is thin in females, and thicker in males.

platy
Fish	Picture	Description
Platys or Platies are a small (2"-3") freshwater, tropical fish from Central America. They are richly-colored schooling fish (keep in groups of 5 or more). They are livebearers (give birth to young fish instead of eggs) and extremely easy to breed. Platies and swordtails are the same group and can usually interbreed. They prefer alkaline water, pH 7.0-8.5. They need vegetable content in their flake food - Spirulina flakes are a good option.
Common Platy Xiphophorus maculatus		A delightful and active fish to keep. Extremely easy to breed, even by first-timers. They come in a dazzling array of colors, from solid bloodred to yellow-black bursts on a white background. Females are more rounded, males have a modified (rod-shaped) anal fin (i.e. in the lower midsection, pointed down). Before you mix sexes, make sure you want fry.
Green Swordtail Xiphophorus hellerii		Females are larger but lack the swords that the males have. The sword is an elongation of the lower tailfin. They are relatively larger (long and slender) platies - 5" for males and 6" for female.

molly (and guppy)
Fish	Picture	Description
Mollies or Poecilia are small (2"-3") freshwater, tropical fish from Central America. Like Platies, they are also livebearers that breed easily, and live in schools (always keep in groups of 5 or more). They like alkaline water, pH 7.0-8.5, and need vegetable content in their flake food (e.g. Spirulina flakes). Some mollies prefer brackish water, i.e. thrive when some aquarium salt is dissolved in their water.
Black Molly Poecilia sphenops		Usually bred selectively to be pure black. Avoid those with grotesquely-shaped fins or gonopodium (anal fin, lower midsection fin) as that is indicative of excessively selective breeding.
Gold Molly Poecilia sphenops		Very similar to the black molly. Its color is produced by selective breeding. In the wild, this species has a common silver color with slight coloration.
Sailfin Molly Poecilia latipinna		The fin is quite beautiful to look at. They prefer brackish water. Males have a shorter lifespan (2 years) compared to most livebearers (5-8 years).
Guppy Poecilia reticulata		These are a small fish (1"-2"), found in an incredible diversity of colors and fin shapes. Very easy to keep and breed. Females are larger than males. They can tolerate various salinity levels (including seawater), but sudden variations are harmful to them.

killifish
Fish	Picture	Description
A very diverse family of small (1"-4") freshwater fish. Their name comes from the word kilde (which means "pond" in Dutch). These are tough to find in fish stores, and eggs usually must be ordered via mailorder or from online stores. These are not a schooling fish, and one or two can be kept by themselves.
Blue Lyretail Fundulopanchax gardneri		A beautiful fish, they originate from Nigeria, and are the most popular killifish. They are 2"-3", like soft water, and prefer slightly acidic water (pH 6.5-7.0), but can tolerate a wider range (pH 6.5-8.0). 70-75°F is good temperature for them. Can be fussy about wanting live food, unless they eat flakes from birth. Usually a mellow, peace-loving fish.
Bluefin Notho Nothobranchius rachovii		Stunningly beautiful. A peaceful fish, but two males will be rough with each other. A male will pick on a female. Multiple males will sort-of get along, one male with multiple females will be fine. Around 2", and prefer pH 6.5-8.0. Originate in East Africa.
Lyretail Panchax Aphyosemion australe		They prefer soft, acidic water (pH 6.0-7.0). Males have a stronger golden hue than females. Very interesting fin and tail shapes.

loach (or botia)
Fish	Picture	Description
Loaches are a tropical, scavenging, freshwater fish. Due to their dwelling and feeding habits, they tend to be relatively non-fussy about their food and water conditions (pH 5.5-8.0). They thrive in warmer water (75-85°F). Many varieties have a pronounced spine under the eye which is deployed when the fish feels threatened. This can easily get entangled in nets, so nets should be avoided with loaches. They need plants and strong currents in the tank. They are social, and should be kept in groups of 4 or more. Too much lighting or lack of plant cover stresses them. They are mellow, so tankmates that are too aggressive or hyperactive will stress them. Also, they fare best with food that sinks to the bottom, so sinking pellets should be part of their diet.
Clown Loach Chromobotia macracanthus		Also called Tiger Botia. This is a large fish, ranging 8"-12", and really need a tank that is 100 gallons or larger.
Kuhli Loach Pangio kuhlii		A relatively small (3"-4") fish, that likes to burrow into the substrate and hide. Its body has an eel-shape. They prefer acidic water (pH 5.5-7.0).
Yoyo Loach Botia almorhae		Called "yoyo" because that is what their skin pattern appears to spell. Prefer slower moving water relative to other loaches. Famous for a clicking noise they make while feeding, and tend to be more daring than other loaches (but still quite mellow). Size is in the 3"-5" range.

cichlid
Fish	Picture	Description
Cichlids are a diverse group of mid-sized fishes. They are not the easiest fish to keep, but have become popular due to their distinctive shapes and coloration. There is an incredibly diverse range of cichlids that comes from the African Great Lakes (Lake Malawi, Lake Victoria, Lake Tanganyika) region. They usually prefer very warm, acidic water. Diet is varied and flakes, pellets and freeze-dried larvae are all good for them. Cichlids tend to form strong mate-bonds, and are nurturing towards eggs and their young. They can be aggressive with tankmates, and are not good companions for more mellow fish.
Angelfish Pterophyllum scalare		Come in a wide variety of colors, and grow to about 4" long by 4" high. They prefer warmer water (80°F) that is slightly acidic (pH 6.5-7.0). Flake food and freeze-dried bloodworms should be included in a varied diet. They are suceptible to death by overfeeding, so be careful not to. Avoid fats in their diet. They are aggressive when they eat and will not allow smaller tetras or livebearers to feed - so are bad tank companions for them. Some varieties are easy to breed (e.g. pterophyllum scalare), while others (e.g. pterophyllum altum) are a lot harder. They are monogamous. Wild-caught angelfish are more aggressive and less tolerant of water quality issues than aquarium-bed ones.
Discus Symphysodon discus		A challenging fish to care for, and definitely not recommended for beginners. They prefer water even warmer than the angelfish (84°F). Water should be very soft and acidic (pH 5.5-6.5), and water-quality must be excellent (25% weekly water changes without fail) or they sicken. Very fussy eaters that resent any changes in diet (they will refuse food for days on end), so avoid any sudden changes and introduce new foods only gradually. Flakes, pellets, freeze-dried worms are all suitable.
Blood Parrot Cichlid Cross-species Hybrid		This is a human-created, usually infertile hybrid that has physical deformities - their mouths cannot completely close (they must use their throats to "chew" food) and they are susceptible to swimming problems. Even though they are popular, please avoid buying or breeding them.
Zebra Cichlid Archocentrus nigrofasciatus		Also called the Convict Cichlid. Albino variants are available. Ranges 4"-6" in size (males are larger than females), but quite aggressive and can be kept with fish larger than itself. They will hassle more mellow fish to death. Wide pH tolerance (6.0-8.0) with usual tropical temperature (75°F) preferred. They breed readily, with strong pairing similar to other cichlids. Very protective of young fry. They like flakes, pellets, freeze-dried worms and some plant matter (algae or chopped broccoli/spinach).
Livingston's Cichlid Nimbochromis livingstonii		One of the many cichlid varieties from Lake Malawi. Females and juveniles are brown and white. Males have a beautiful blue overlay which deepens at breeding time. They are mouthbrooders (i.e. shelter the young in their mouths). They are larger (10") predators that like eating fish, and hunt by lying motionless like a dead fish until a smaller fish ventures close enough. Territorial (keep rocks to allow them to claim zones) and aggressive. Tank should be 130 gallons or more, with alkaline water (pH 7.5-8.5, ideal at 8.0) at about 78°F. Definitely not recommended as a beginner fish, and should be kept in a dedicated Malawi-environment tank.

gourami (and betta)
Fish	Picture	Description
Gouramis are a relatively aggressive family of fish (e.g. they will simply eat any guppies they find, unless raised with them from a very young age). They are labyrinth fish (i.e. have a lung-like labyrinth organ with which they can directly breathe air for short time periods, so long as they stay moist), so often tend to lurk at the upper levels of an aquarium. Make sure there is room for fresh air to collect above the water surface - but the aquarium-top should be enclosed as they are known to jump out. Diverse and beautiful in coloration, the popular bettas belong to this family. Good tankmates to some cichlids. They need varied food, including flakes, worms and vegetable material. They strongly prefer natural plants in the aquarium and slow currents.
Betta Betta splendens		Also known as the Siamese Fighting Fish. Extremely territorial - a males will another betta (male or female) will fight it to the death. Must be kept alone. Multiple females can stay in a group (a "betta sorority") with enough aquarium space, but the dominant female can kill one or more of the members at any time, even after months of apparent peace.
Gold Gourami Trichogaster trichopterus		Also called Blue Gourami or Cosby Gourami depending on coloration. Grows to 3"-5". Wide pH range (6.5-8.5). Pairs build nests, and males guard the nest and fry after spawning.
Dwarf Gourami Colisa lalia		Available in a variety of colors, including blue. More peaceful than other gourami, though they will fight with another of the same type. They are territorial, so define their space and tend to defend it.

cyprinid (and goldfish)
Fish	Picture	Description
Cyprinids are an extremely popular and very broad group of aquarium fishes related to carps, that span both larger fish (Goldfish, Koi) and small minnows (Rasboras, Barbs, Danios). They are schooling fish, and the smaller members of the family are easy to keep and come in a vast variety of colors, which makes them excellent choices for the aquarium. Many have sensitive "barbells" on either side of their mouths (hence the name "Barb") that help them locate food on the substrate/floor.
Goldfish Carassius auratus		Goldfish are not a good beginner fish. Relatively long lived (15-20 years) and large (10"-18"), i.e. budget at least 10-18 gallons per fish. Goldfish bowls are cruel, result in stunting and atrophying, and very early death - don't use them. Wide pH tolerance (6.0-8.0). Prefer colder and more variable temperatures (set heater at 60°F). Tolerate brief rises to 85°F, but prefer below 75°F. Feed flakes, freezedried worms, vegetable food, and special "made-for-goldfish" food (such as TetraFin Goldfish Flakes). Generally peaceful, but can eat smaller fish. Susceptible to Swim Bladder Disease. Messy (they poop a lot), so a strict regimen of 25% weekly water changes is a must.
Koi Cyprinus carpio		Koi are basically a beautiful, prized strain of the common carp. Even more than goldfish, they are large (2'-4'), long-lived (30 years or more) and prefer relatively colder water. They are too large to be a normal aquarium fish (should really be kept in ponds), and also produce a lot of waste, which means the tank needs to be even larger than it normally would. Koi shouldn't be kept in tanks less than 100 gallons.
Harlequin Rasbora Trigonostigma heteromorpha		Also called the Red Rasbora. A hardy, small fish (1.5"-2") that prefers usual tropical temperature and mildly acidic water (pH 6.0-7.5). They are a peaceful, schooling fish (keep in groups of 4 or more) and like dense vegetation and soft lighting. They eat flakes and freeze-dried food. A very good aquarium choice. Tough to breed. The black triangle on their bodies has relatively straight lines in females, whereas the bottom line tends to be curved in the male (and the triangle goes lower, closer to the fin).
Blackline Rasbora Rasbora borapetensis		Also called the Red Tailed Rasbora. Very similar to the Harlequin Rasbora in size, temperament, water preferences and food habits.
Gold Barb Puntius gelius		Also called China Barb. A great, hardy aquarium fish. Usually 2"-3". They have a broad pH tolerance (6.0-8.0). They are a schooling fish (keep 5 or more), and extremely active. They need plenty of room to swim and some vegetation to keep their stress levels low. Don't keep them with more placid fish that will be stressed by the barbs' sudden movements, but they do well with both Gouramis or Platys. They prefer a slightly cooler temperature (70°F). Males have a deeper golden hue than females and are thinner. They must be fed a varied diet (flakes, freeze-dried worms and vegetables such as lettuce or boiled broccoli/zucchini).
Tiger Barb Puntius tetrazona		Sized 2"-3", they have broad pH tolerance (6.0-8.0), but prefer slightly acidic water. Albino and Green-tinted (sometimes called Moss Barbs) variants are available. Prefer normal tropical temperature 75°F. Feed them flakes, worms and vegetable matter. Males are smaller, more vividly colored, and have both a reddish-brown nose and a distinct red fringeline on the rear edge of the dorsal fin. They can nip the fins of slower fish (e.g. Neon Tetras).
Zebra Danio Danio rerio		Also called the Zebra Fish. An excellent aquarium fish. About 2", they prefer slightly cooler temperature (around 70°F) and slightly alkaline water (pH 6.5-7.0), but can live with broader conditions (75°F, pH 6.5-8.0). They pair for life and breed easily. Females are larger and rounder than males. They are a schooling fish and should be kept in groups of 5 or more. A very active fish that needs open space to swim. Feed them a varied diet (flakes, worms, vegetable matter).

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Fishes

selecting fish