Not furry, but we like them anyway.
Rosy Bitterling
Rhodeus ocellatus
Also called Rhodeus ocellatus ocellatus (nominate subspecies)
From Eastern Asia, from the Amur River basin south to the Pearl River basin, including Taiwan and parts of Russia12
A friendly guide, not veterinary advice. For anything about your pet's health, ask your vet.
At a glance the quick version
Looks how to spot one
Small, deep-bodied, laterally flattened carp relative
A compact, flat-sided little fish with a bright silvery sheen. In the breeding months males take on rosy red to purple tones, which is where the name comes from, and females grow a thin egg-laying tube.21
Personality what they are like
A small, schooling fish of quiet, weedy water. Males become showy and attentive during the spring and summer breeding season.21
Grooming and care the hands-on bits
To see natural breeding the setup needs living freshwater mussels, as the female places her eggs inside them.21
Home where they are happiest
A temperate fish of shallow ponds, marshes and slow canals. FishBase gives a water temperature of about 18-24 C, pH up to 7.0 and hardness of 10-15 dH.1
Food basics what goes in the bowl
An omnivore that picks at small food items and plant or detritus matter.1
The story where it all began
The rosy bitterling is native to the river systems of East Asia. It reached Japan by accident in 1942, mixed in with shipments of grass carp and silver carp from mainland China, and has spread widely there since.2
Fun facts for the dinner table
- 1
Females lay their eggs inside living freshwater mussels, and the young stay inside the mussel until they can swim.1
- 2
A female may spawn around ten times in one season, roughly every six to nine days, laying just two or three eggs each time.2
- 3
Hatchlings measure only about 2.8 mm and leave the mussel at about 7.5 mm long.2
- 4
Young rosy bitterlings have a body shape compared to the bud of a matsutake mushroom.2
Recognised by the official bits
- IUCN Red List
- Data Deficient (assessed 4 September 2010)1
- FishBase
- Listed as used in the commercial aquarium trade1
- Taxonomy
- Two subspecies recognised: R. o. ocellatus and R. o. smithii2
The care rhythm Furry Diary remembers it for you
A typical home-care rhythm for a Rosy Bitterling. It is our own starting plan, not a vet's advice, and you can change every line in the app.
- Feedingevery day
- Water changeAbout 25 to 30% of the waterevery week
- Water testevery week
- Glass cleanevery week
- Filter rinseevery month
Owner questions the things everyone asks
How often should I feed my Rosy Bitterling?
Feed your Rosy Bitterling once a day. Furry Diary's starting plan is to feed daily. Adjust the amount based on the food label and your vet's advice.1 Furry Diary plan
What does a Rosy Bitterling eat, and what should it never eat?
Your Rosy Bitterling is an omnivore that picks at small food items and plant or detritus matter. Never give it any food that is not suitable for small fish; ask your vet or a good breeder for a safe list.1
How much space does a Rosy Bitterling need?
Space needs vary by tank size and number of fish. For a small schooling fish like this, ask a good breeder or exotic-pet vet for the right tank volume. A larger tank is always better for water stability.
What temperature, light or water does a Rosy Bitterling need?
Keep the water temperature between 18-24°C, pH up to 7.0, and hardness of 10-15 dH. This temperate fish comes from shallow ponds and slow canals, so gentle lighting is best.1
How often should I clean a Rosy Bitterling's home?
Furry Diary's starting plan suggests a weekly water change of about 25-30%, a weekly glass clean, and a monthly filter rinse. Always test the water weekly to keep it healthy. Furry Diary plan
Can a Rosy Bitterling live with others?
Yes, Rosy Bitterlings are a small, schooling fish that enjoy company of their own kind. They are peaceful and do well in a quiet, weedy setup. For tank mates, ask a good breeder or vet.21
How long does a Rosy Bitterling live?
Lifespan varies with care and environment. For a precise answer, ask your vet or a good breeder who knows the species well.
Can I handle a Rosy Bitterling?
It is best not to handle your Rosy Bitterling. They are delicate fish and handling can stress or harm them. Enjoy watching them in their tank instead.21
Written from the sources on this page, a few checked guides (VCA, ASPCA, RSPCA) and Furry Diary's own starting care plan. A friendly guide, not a vet's advice.
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Where this comes from
Every breed page shows where each fact comes from. If we got something wrong, sorry, we are pet people, not a science magazine. Tell us at support@furrydiary.app and we will fix it.
- FishBase: Rhodeus ocellatus fishbase.seused for size, distribution, water parameters, reproduction, IUCN status, trade use
- Wikipedia: Rosy bitterling en.wikipedia.orgused for size, colours, reproduction, history, subspecies, fun facts
- VCA Animal Hospitals: Feeding times and frequency for your dog vcahospitals.comused for owner questions
- ASPCA: Dog grooming tips aspca.orgused for owner questions
- ASPCA: Cat grooming tips aspca.orgused for owner questions
- ASPCA: People foods to avoid feeding your pets aspca.orgused for owner questions
- RSPCA: What to feed your rabbit rspca.org.ukused for owner questions
Checked 2026-09-30. Text is written in our own words from these sources.