Amur bitterling

Bitterling
Conservation status
Least Concern
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Cypriniformes
Family:	Cyprinidae
Genus:	Rhodeus
Species:	R. sericeus
Binomial name
Rhodeus sericeus (Pallas, 1776)

Male Rhodeus sericeus from the Betuwe, the Netherlands, end of winter.

The bitterling, Rhodeus sericeus, or Amur bitterling is a small fish of the carp family. Mussels form an essential part of its reproductive system, with bitterling eggs being laid inside them.

Long thought to be symbiotic with the mussels (whose larval phase attaches to fish gills during development), recent research has indicated they are in fact parasitic, with co-evolution being seen in Chinese bitterling and mussel species.

Bitterlings usually reside in areas with dense plant growth. They are a hardy fish, and can survive in water that is not very well oxygenated. They grow to be 3-4 in. long at most. The bitterling's diet consists of plant material and small larvae of insects.

Colour Variation

There are 'transparent' scale variants of bitterlings, though not common, if exploited in the aquarium trade.

For photos of transparent variants of bitterlings, please see: http://www.jstage.jst.go.jp/article/zsj/15/3/425/_pdf

References

• Template:IUCN2006
• "Rhodeus sericeus". Integrated Taxonomic Information System. 11 March. {{cite web}}: Check date values in: |date= and |year= / |date= mismatch (help)
• Froese, Rainer; Pauly, Daniel (eds.) (2005). "Rhodeus sericeus" in FishBase. 10 2005 version.
• "Bitterling are parasites not symbionts". Practical Fishkeeping.