How To Identify
Fish Families Fast
(December 2002 page 6)
John Todaro BAS

There are eight major families of fish that you will generally find in aquarium stores.

Here is a brief guide of some of their major characteristics and behaviors to help you identify them.


Barbs
Family: Cyprinidae
Habitat: South East Asia
Egglayers

Small active fish, grows 2 to 4 inches on average. Most common in pet stores are tiger barbs, clown barbs, cherry barbs, tinfoil barbs, and rosy barbs.

You can spot a Barb by these characteristics:

1. Larger scales
2. Barbels (small whiskers on lower jaw)
3. Stocky body
4. Barbs do not have a small lobe-like fin behind the dorsal called the “adipose fin”.
5. Active swimmers and like to school.
6. Tough to tell but Males are more colorful then females.

Barbs are a good fish for a beginner to start a tank with. They are colorful, tough, active when kept in schools (6 fish and up make them feel comfortable) and are undemanding in the aquarium and easy to feed, will take flake food readily.

Goldfish
Family: Cyprinidae
Habitat: Captive Breed
Egglayers

Most common in pet stores are; goldfish, carps, and koi, The largest family of fish in the world. They vary in size from 1 inch to over 6 feet. Most are small and brightly colored.

You can spot a Carp by these characteristics:

1. Goldfish have no barbels (mouth whiskers).
2. They do not have an adipose fin.
3. Head generally scaleless, body evenly scaled.

A good fish for beginners. Keep in mind that goldfish and Koi like cold water and should never be kept with tropical fish who need much warmer water. Gold fish and Carp and Koi make great pond fish.


Catfish
Family: callichthyidae
Habitat: Africa, Asia, South America
Egglayers


A larger family of fish. They range in size from less than 1 inch to a couple of feet. In general the ones in your pet store will range from 1 to 8 inches.

You can spot a catfish by these characteristics:

1. Catfish do not have scales.
2. Generally brown, black and white colorations
3. Have flat underside, appropriate for life as a bottom dweller.
4. To tell which catfish are safely kept in a community tank, look at their mouths. Pointed down or a sucker mouth, the fish is probably OK. A larger mouth or a forward-facing or slash mouth means trouble.
When they get larger these fish could eat their tank mates.

Catfish are excellent fish for a community tank. They are bottom-dwelling fish. Most are nocturnal and actively feed at night.


Cichlids
Family: cichlidae
Habitat: Africa, South & Central
America
Egglayers

A larger, diverse family that includes fish with many different water requirements. Intelligent, with interesting spawning and parental care of their young. They are territorial and can be aggressive

You can spot a Cichlid by these characteristics:

1. Classical fish shape.
2. Prominent fins.
3. Some have jewel-like colors.
4. Many are aggressive.
5. Ranges in size from 1-1/2 to 12 inches and more.
6. Males are more colorful and larger then females.

Young Cichlids do well in community tanks, but as they get older and larger they will bully other fish, sometimes to death.

Killifish
Family: cyprinodontidae
Habitat: Africa, America, Asia,
South America
Egglayers

Small slender fish that are not often seen in pet shops, but can be acquired from other hobbyists and killie clubs.
A larger family of over 500 species, most live in the tropics. They range in size from 1 to 4 inches. A few species in this family grow up to 8 inches. They have been called annual fish, because in nature many species live in streams or ponds that become seasonally dry.

You can spot a Killifish by these characteristics:

1. Killifish have no barbels.
2. Their heads are flattened on the top.
3. Most have round small scales.
4. Killies’ lateral line is restricted to the head area only.
5. Killifish are prized for their vividcolors and /or flowing fins.
6. Males are more colorful and larger then females.

They do best in specimen tanks of 2 to 5 gallons. Not recommended for the beginners they do have special requirements.


Anabantoids
Family: Belontidae
Habitat: Southeast Asia
Egglayers

Most common in pet shops are blue, pearl, and dwarf gouramis. Bettas, and paradise fish are also commonly found. This family, ranges from Southern African and Southeast Asia where they live in stagnant, oxygen-poor water and have developed a special breathing chamber above their gills which allows them to breath atmospheric oxygen. They average in size from 2 to 6 inches in the home aquarium.
When breeding, the male constructs a bubble nest from air and saliva, place the eggs in the bubbles, then guards them until they hatch.

You can spot an Anabantoid by these characteristics:

1. They are colorful.
2. Look for long ventral fins that look like feelers.
3. Up turned mouth.
4. Males are generally more colorful than the female.
5. Male has pointed dorsal fin.

This is an excellent family of fish to start with, since they can tolerate poor water conditions, as long as their water is kept warm.


Livebearers
Family: Poecilidae
Habitat: Central America
Livebearers

Most commonly found in pet stores are guppies, platies, swordtails and mollies.

A large family of fishes that range from North, Central, South America and Caribbean Islands. They average in size from less than 1/2 inch to about 3 inches. They are generally peaceful and prolific. Males are more colorful and often smaller then females. These fish do well in community tanks so long as they’re kept with fish about their own size. They like alkaline water but will tolerate neutral pH water and will accept all types of dry and live foods.

You can spot a Livebearer by these characteristics:

1. Males can be identified by their gonopodium.
2. Females by a rounded body and a gravid spot above their ventral fin which is rounded.
3. The male is more colorful than the female.
4. Livebearers have upturned mouths; they are surface feeders.
5. They are mid-water dwellers.
6. Active swimmers; males court females continuously.

They are an excellent fish to start with. They reproduce quickly without the help of the hobbyist. They will eat their young if they find them. It is suggested the tank be thickly planted or the young be
separated from the parents after birth

Tetras
Family: characidae
Habitat: Central & South America
Egglayers

Most common in pet stores; black tetra, brass tetra, neon tetra, lemon tetra, cardinal tetra, head and tail light tetra, blind cave fish, etc.A large family of fish distributed throughout South and Central America.

You can spot a Tetra by these characteristics:

1. Tetras have no barbels.
2. Look for a small fin between the dorsal and tail fin. It is called the adipose fin.
3. Brightly colored, silver, black, reds, yellows and blues.
4. Range in size from 1 to 4 1/2 inches.
5. Active schooling fish, should be kept in groups of 6 or more fish of the same species.
6. Not aggressive, but can be rambunctious at times.

A good fish for the active community tank. Kept in schools of 6 to 15 fish and they will swim together. An excellent fish to keep in species tanks. In large groups, 20 and more schooling tetras are a beautiful sight .