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💧 Freshwater Near Threatened 🍽️ Edible 🌡️ Tropical

Marmorated medaka

Oryzias marmoratus Aurich, 1935
Max Length
4.1 cm
Max Weight
-
Lifespan
-
Trophic Level
3.4
Depth
-
Climate
Tropical
Resilience
Low
Vulnerability
10.00/100
Typical Length
-
Depth Zone
-

📖 Overview

Non-annual breeder. Is very difficult to maintain in aquarium . In 2013 and 2018, the collected and observed specimens were only during the day and at TanjungTimbala, slightly south of the type locality, and at Lengkona in Lake Towuti. This species is collected with O. loxolepis and O. profundicola that form schools in gently sloping, shallow (< 1.5 m) shore areas with large boulders and submerged wood over sand and gravel. Other taxa occurring in samples included Paratherina spp., Glossogobius flavipinnis, G. intermedius, Glossogobius sp., Mugilogobius rexi, M. latifrons, and Nomorhamphus megarrhamphus. In Lake Lantoa, it inhabits gently sloping, shallow shores (1 m depth) with a large area of plants on a muddy substratum. It swims in schools and was collected in association with Telmatherina celebensis and Glossogobius sp. (an undescribed lake endemic: HK, pers. obsv.). Some individuals were infested with parasitic copepods. In Lake Mahalona, it also inhabits gently sloping, shallow shores (1 m depth) with large boulders over a sand and gravel substratum, covered with aquatic vegetation. Often, it also forms schools and co-occurring with Tominanga aurea, Glossogobius sp. (as for Lake Towuti), Glossogobius mahalonensis, G. intermedius, M. rexi, and Mugilogobius cf. hitam .

Scientific Name
Oryzias marmoratus
Authority
Aurich, 1935
Habitat
Freshwater
Climate
Tropical
IUCN Status
NT
Max Length
4.1 cm
Trophic Level
3.4
Resilience
Low
Vulnerability
10.00/100
Migration
Non-migratory
Water Temp
22–25 °C
Salinity
0–0.5 ppt

🐟 Physical Description

Dorsal soft rays (total): 9 - 10; Anal soft rays: 22 - 25. This species is distinguished (from O. profundicola, O. loxolepis) by the following characters: abdominal vertebrae usually 12, total vertebrae 29-31; D 9-10, A 22-25; transverse scales 10-11; body depth at anal-fin origin 24.8-30.1% SL and at dorsal-fin origin 20.2-25.3% SL; caudal peduncle length 12.0-16.3% SL; distinct nuchal concavity; lateral scales are more-or-less aligned parallel to midlateral stripe; male with elongated-shaped dorsal fin without yellow margin .Cross section: compressed.

🌀 Behaviour

Behavioural data for Marmorated medaka is currently being reviewed.

🦐 Diet

aquatic invertebrates
small fish
algae
detritus

🥚 Reproduction

🐣 Oviparous
Spawning Season
spring
Spawn Location
Substrate
Fertilization
External

Egg clusters are carried by females under the ventral fin .

🌍 Habitat & Distribution

Freshwater; benthopelagic; pH range: 7.5 - 8.5; non-migratory. Tropical; 22°C - 25°C

🌿 Ecology

Zone Preferences
💧 Freshwater
Migration
Non-migratory
Trophic Level
3.4±0.4
🐠 Schooling

📐 Morphometrics

Length–Weight Relationship: W = 0.00437 × L3.11 (TL)
Max TL
4.1cm
Dorsal Rays
10
Anal Rays
24

🌡️ Water Parameters & Tolerance

Temperature Range
22–25°C
pH Range
7.5–8.5
Salinity Range
0–0.5ppt

🛡️ Conservation Assessment

IUCN Category
Near Threatened
Assessment Date
2018

📊 Population Risk & Fisheries

Population Resilience
Low
Minimum doubling time
Fishing Vulnerability
10.00/100
Low vulnerability
Trophic Level
3.4
Predator
Climate Zone
Tropical
Described By
Aurich, 1935

🍽️ Edibility & Flavour

"Oryzias Marmoratus is an edible species."

✗ Not for Raw
✓ Fresh Indicators
  • Clear, bright eyes — cloudy eyes indicate age
  • Firm flesh that springs back when pressed
  • Fresh ocean smell, never strong or ammonia-like
  • Bright red or pink gills, not grey or brown
  • Shiny, moist skin with scales tightly attached
✗ Avoid If
  • Cloudy or sunken eyes
  • Strong fishy or ammonia odour
  • Soft, mushy flesh that doesn't spring back
  • Discoloured or dry flesh
Best Cooking Methods
Baking Grilling Pan-frying

⚡ Nutrition

Detailed nutritional data for Marmorated medaka is currently being compiled from USDA FoodData Central.

🔬 Mercury Safety

Mercury data for Marmorated medaka has not yet been assigned. Please consult FDA/EPA guidance for general seafood safety advice.

🌿 Sustainability

Best Choice
Healthy stocks, low impact
Good Alternative
Well-managed, minor concerns
Use Caution
Check sourcing and season
Avoid
Overfished or high impact
✓ Sustainable Choice

🔬 Full Nutritional Profile

Per 100g - Raw, per 100g - Source: USDA FoodData Central templates (generic fish average)

Proximate Composition
Energy125 kcal
Moisture75 %
Protein20 %
Total Fat4 %
Ash1.3 %
Fatty Acids (g)
Saturated Fat1 g
Monounsaturated Fat1.2 g
Polyunsaturated Fat1.5 g
Omega-3 Total1 g
EPA0.3 g
DHA0.5 g
Omega-6 Total0.3 g
Key Minerals & Vitamins
Calcium20 mg
Iron0.7 mg
Magnesium30 mg
Phosphorus220 mg
Potassium380 mg
Sodium55 mg
Zinc0.5 mg
Selenium32 µg
Vitamin B122 µg

📊 Population Dynamics

Year Region Index Notes
- - -

👥 Community & Contribute

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