How to Identify Freshwater Tank Fish

The hobby of tropical fish-keeping is currently enjoying an increase in popularity. Among the many reasons for this are a general increase in environmental awareness, along with the growing recognition of the enjoyment and relaxation that owning an aquarium can bring to people of all ages. Tropical fish are relatively easy to care for and not as expensive as coral reef fish and invertebrate animals. However, not all tropical fish can be housed together, and it is important for the hobbyist to be able to identify the various species that are offered for sale.

Things You'll Need

  • Current fresh water fish identification guide
Show More

Instructions

    • 1

      Examine the mouth of the fish. The location of a fish̵7;s mouth on its body will indicate its feeding habits and allow you to place the fish into one of the many fish families.

    • 2

      Begin your identification with the bottom-dwelling group of fish. These fish normally have inferior or underslung mouths, sometimes with barbells or whiskers. Certain bottom-feeding fish will also have a suction-like mouth. A number of cat fish types and loaches are included in the bottom-dwelling group of freshwater fish types.

    • 3

      Look at the mid-water feeders next. These fish have terminal mouths, which face forward and look like the type of mouth that we commonly associate with a "fish" look. Mid-water feeders include many species, encompassing many popular aquarium fish such as angel fish, oscars, guppies and tetras.

    • 4

      Identify those fish with superior or upturned mouths. Fish in this group, feed from the surface of the water and include species such as the betas and hatchet fish. This group of fish does not contain as many members as you will find among the mid-water feeders.

    • 5

      Examine the fins of the fish as well. Fins propel a fish through the water and tell us much about how each type lives, and thereby into which broad family it belongs.

    • 6

      Look for fish that live in open water. These fish will have powerful or large fins that allow them to move with speed to escape predators or to capture prey. Zebra danios and mollies belong in this group.

    • 7

      Examine the fins of those fish that you have already identified as bottom-dwelling. These fish, which include the various cat fish, will have splayed fins on their underside to help them hug the gravel or rocks on the bottom of rivers or lakes.

    • 8

      Examine the body shape of the fish, to be absolutely sure that you have made the correct identification.

    • 9

      Notice that the dorsoventrally-compressed fish live on or near the bottom. These fish have relatively flat bellies for life on the river substrate. The cat fish is part of this family.

    • 10

      Look for the deep-bodied, plate-shaped fish between the submerged roots of trees that grow along river banks. Discus and angel fish are found in this category, which incorporates the mid-water feeders.