Munahosi cardinalfish
Ostorhinchus cheni
Munahosi cardinalfish exhibits a slender body, strikingly patterned with a mix of vibrant orange and blue hues, and features elongated dorsal fin rays.
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About the Munahosi cardinalfish
Think of a deepwater cardinalfish with a moody, reddish body, two slim dusky stripes, and a bold spot at the tail base. It hangs in the shadows, cruises slowly, and the male mouthbroods eggs, which is wild to watch if you ever see it happen. Super cool fish, but it comes from 70-100 m and prefers cooler marine temps, so it is definitely a specialist project.
Also known as
Quick Facts
Size
13 cm
Temperament
Peaceful
Difficulty
Expert
Min Tank Size
55 gallons
Lifespan
5-8 years
Origin
Indo-West Pacific
Diet
Carnivore - zooplankton and small crustaceans; readily takes frozen mysis, enriched brine, and finely chopped marine meats
Water Parameters
15-23°C
8.1-8.4
50-100 dGH
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Calculate heater sizeCare Notes
- Give them a rocky reef layout with deep caves and overhangs so they can lurk in shade; bright lights make them hide and skip meals.
- Run stable marine params: 76-80 F, 1.024-1.026 SG, pH 8.1-8.4, zero ammonia/nitrite, and keep nitrate under ~15 ppm with strong aeration.
- Feed at dusk or under dim blues; start with live or freshly frozen mysis, enriched brine, and copepods, then wean to small frozen blends in 2-3 small meals daily.
- They have tiny mouths and are slow feeders, so avoid tankmates that blitz the food (aggressive wrasses, dottybacks, big hawkfish, boisterous tangs).
- Best kept solo or as a proven pair; groups often sort themselves with nasty pecking once they mature unless the tank is large and maze-like.
- Reef-safe with corals, but they can pick off nano shrimps and crab larvae; full-size cleaner shrimp are usually fine.
- Quarantine new arrivals for 3-4 weeks and focus on getting them eating; use medicated food for internal parasites and go light on copper if you must treat.
- Breeding is mouthbrooding by the male; if his jaw looks stuffed and he stops eating for ~10-14 days, move him to a quiet box near release and have rotifers/baby brine ready for the tiny fry.
Compatibility
Good Tankmates
- A small group of their own kind (3-6 O. cheni) with plenty of caves so they can hang under ledges together
- Peaceful gobies that stick to the sand and rocks (neon, watchman, clown gobies)
- Mellow blennies like tailspot or lawnmower that graze and ignore them
- Firefish and dartfish that share the midwater without drama
- Fairy and flasher wrasses that are reef safe and not pushy
- Royal gramma or chalk bass that keep to the rockwork and do not crowd them
Avoid
- Aggressive damsels or pugnacious clowns (maroon, tomato, three-stripe) that will bully shy fish
- Dottybacks and pseudochromis that love to harass quieter fish hiding in caves
- Predators that see small cardinals as snacks (lionfish, groupers, large hawkfish)
- Big rowdy wrasses or triggers that never stop moving and will outcompete or nip
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