The striped bitterling (''Acheilognathus cyanostigma'') is a species of freshwater

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or h ...

in the genus ''

Acheilognathus ''Acheilognathus'' is a genus of cyprinid fish native to Asia. The name is derived from the Greek ''a'', meaning "without", the Greek ''cheilos'', meaning "lip", and the Greek ''gnathos'', meaning "jaw". Morphology Fishes of this genus have l ...

''. It is endemic to

Lake Biwa is the largest freshwater lake in Japan, located entirely within Shiga Prefecture (west-central Honshu), northeast of the former capital city of Kyoto. Lake Biwa is an ancient lake, over 4 million years old. It is estimated to be the 13th o ...

and Lake Yogo in Japan. It typically grows to a length of 6.0 cm. The reproduction for the creation of the Kyushu bitterling happens with the

Mussel Mussel () is the common name used for members of several families of bivalve molluscs, from saltwater and freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other edible clams, whic ...

as their eggs spawning substrate which is also a species living in freshwater habitats. While in spawning season the father protects the area around the chosen mussel as the mom proceeds to lay her eggs in the inhalent siphon of the mussel. The father will late find his time to release his sperm as well and for a month the sperm released will be carried by the water going through the filter process in the mussel into the eggs for the development of life.

References

Acheilognathus Freshwater fish of Japan Fish of Japan Lake fish of Asia Fish described in 1903 {{Acheilognathinae-stub