Lightest freshwater fish
- Who
- Dwarf pygmy goby, Pandaka pygmaea
- What
- 0.004 – 0.005 gram(s)
- Where
- Not Applicable
- When
- N/A
The lightest-known freshwater fish is the dwarf pygmy goby (Pandaka pygmaea), a colourless and nearly transparent species found in streams, rivers and lakes of Luzon in the Philippines, as well as in mangrove areas of Singapore and several Indonesian islands. Mature males are typically only 9–11 millimetres (0.28–0.38 inches) long and weigh 4–5 milligrams (0.00014–0.00018 ounces), making them the lightest-known freshwater fish based on current available data; female dwarf pygmy gobies are slightly longer at 15 millimetres (0.5 inches).
Another species currently claims the record based on length. In 2006, scientists announced the discovery in highly acid Sumatran and Bornean peat swamps of a bizarre, transparent relative of the carp, which has been named Paedocypris progenetica. The smallest adult specimen so far recorded of this new species is a mature female, which measured just 7.9 mm (0.31 in) in total length; the smallest mature male was 8.2 mm (0.32 in). However, no weight samples have yet been recorded for this species.
The dwarf pygmy goby is known in the Philippines by the names bia and tabios.