The Bitterling is kept by many aquarists due to it’s simple yet beautiful markings, hardiness and unique breeding behavior. Since The Bitterling is found in most locations on the globe most species are considered “cold water” fish meaning they can survive in temperatures around 72 F, different than most aquarium fish which are tropical requiring temperatures between 78 F and 82 F. These fish are so diverse however that some species actually come from tropical regions and may be kept with tropical fish.
Types Of Bitterling
The genus Rhodeus has about 22 known species (47 including sub-species), these fish are considered Bitterling Fish or Rhodeus species. Each species has their own variation of the typical general appearance of Rhodeus.
One of the most commonly available Bitterling is the Rosy Bitterling, or Rhodeus ocellatus. The Rosy Bitterling is native to Taiwan and tolerates temperatures between 64 F and 75 F. The Rosy Bitterling has a tall flat body silvery in coloration. The males however get a rosy red color during spawning to attract females.
The other species of Bitterling you are likely to find in a fish store is Rhodeus sericeus, or The Common Bitterling. This species is not as tall or flat as the Rosy Bitterling nor does this species show the rosy color during spawning.
One type of Bitterling, Rhodeus amarus was once used as a pregnancy test for women. The pregnant woman's urine would be injected into a female Bitterling and if the urine had the pregnancy hormones the fish's ovipositor would begin to come out.
The Bitterling’s Unique Reproductive Strategy
One of the main attractions to the Rhodeus genus is the unique manner in which they reproduce. During reproduction in the wild the male will find a healthy freshwater mussel on the riverbed which he will coax into opening up. After successfully coaxing the mussel he will lure a female over where she will insert her ovipositor into the mussels feeding siphon and will lay her eggs. The male then hovers over the mussel and releases his sperm into the water. The mussel will naturally siphon the water full of sperm into itself fertilizing the eggs inside.
After about a month the eggs hatch and free swimming fry come out of the mussel. The mussel is left unharmed and the fry are left to fend for themselves feeding on algae and micro organisms in the water column.
Housing Requirements
Bitterling may be kept in any tank 30 gallons or larger preferably with a fine gravel or sand so live freshwater mussels may be added during spawning. The temperature should be between 64 F and 75 F with a neutral pH around 7.0. Bitterling will accept most flake or pellet foods but should also be supplemented with algae wafers and live brine shrimp to simulate their natural feeding behaviors.
Sources
Dr. Axelrod, Herbert R and Vorderwinkler, William. Encyclopedia of Tropical Fishes 29th Edition. T.F.H. Publications, Inc.. 1988.
Scientific Names Where Genus Equals Rhodeus. January 7, 2012. Fishbase.org.
Froese, Rainier. Rhodeus sericues (Pallas, 1776) Bitterling. Fishbase.org. November 15, 2011. January 7, 2012.
Luna, Susan M. Rhodeus ocellatus ocellatus (Kner 1866) Rosy Bitterling. Fishbase.org. November 15, 2011. January 7, 2012.
Binohlan, Crispina B. Rhodeus amaru (Bloch, 1782). Fishbase.org. November 15, 2011. January 7, 2012.
Evan Eloe - When learning about what he loves Evan leaves no rock unturned giving his readers a clear and well rounded source of knowledge.
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