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Raspy river stingray

Potamotrygon scobina

Also known as Arraia

Fishes › Freshwater stingrays (Myliobatiformes) › Potamotrygonidae (Freshwater stingrays)

The raspy river stingray, mosaic stingray or arraia (Potamotrygon scobina) is a species of freshwater fish in the family Potamotrygonidae.

Aquarium hobby
Experience: Expert / facility
FamilyFreshwater stingrays
Adult lengthup to 21.5 in
WaterFreshwater

Care at a glance

Species-specific aquarium care

  • Tank: At least 108 in long and 42 in front to back for one adult (adults commonly reach about 21.5 in / 54.7 cm).
  • Water: Freshwater.
  • Layout: Uses both the bottom and open water: give open swimming space plus cover near the substrate.
  • Availability: Rarely or never seen in the aquarium trade; expect to source it from specialists or not at all.

Calculated from this species' own FishBase record: tank size from its typical adult length and swimming zone, water values from its recorded ranges. The group guide below fills in general care.

Care guide

Species care notes

  • Tank: a base of at least 71 × 30 in (roughly 214 US gallons); space needed is rated “very large tank”.
  • Water: a fairly wide range, from slightly acidic to slightly alkaline, 75–79 °F, pH 6–7.5, 4–10 dGH.
  • Difficulty: Difficult (Seriously Fish rating).

Short excerpts from the species profile:

  • Setup: “Strictly speaking, decor isn't really necessary in a tank set up to house rays.”
  • Diet: “Wild rays feed chiefly on other fish and aquatic invertebrates, including worms and crustaceans.”
  • Tankmates: “Rays are among the top predators in the ecosystems they populate in nature and are unsafe to keep with most other species.”
  • Breeding: “Potamotrygon species utilise a breeding strategy known as matrotrophic viviparity.”

From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167

Group care guide

Freshwater stingrays

Applies to most species in this group. Habitat: South American rivers. Individual species can differ, so compare with the species numbers above and the linked sources.

Housing & setup

  • Large tanks (often 6×3 ft+ footprint for one adult) with fine sand and excellent filtration.

Sources 117119164118

Diet

  • Earthworms, shrimp and fish.

Sources 117119164118

Health watch

  • Venomous barb; banned in some states.

Sources 117119164118

Understanding the animal

This species is part of a group that hobbyists, aviculturists or zoos keep widely (Freshwater stingrays), so it's included for completeness. It may be rare in captivity itself, or not kept at all. Use the group guide as a starting point and look for species-specific advice from experienced keepers.
About this animal

About this animal

This stingray is endemic to the Amazon basin in Brazil, where known from the Amazon–Pará River (Belém to near the confluence with the Putumayo River), the Madeira River basin, Uatumã River and lower Tocantins River. It reaches up to 69 cm (2 ft 3 in) in disc width and 132.5 cm (4 ft 4.2 in) in total length.

Quoted from the Wikipedia article “Raspy river stingray” (CC BY-SA 4.0) 174

In the wild

In the wild

From this species’ own FishBase record (habitat, bottom type, water and breeding data), not its family. Good care copies these conditions.1

Where it livesLives in freshwater. Uses both the bottom and open water.
Water it lives inFreshwater.
ClimateTropical climate.
Behavior to plan forBreeding: internal live bearers.
  1. FishBase species summary: Potamotrygon scobina
Native climate (measured)

Native climate (measured)

Warm-season highsabout 90°F (up to 94°F in the hottest sampled areas)
Cool-season lowsabout 71°F (down to 64°F in the coldest sampled areas)
Average temperature77–81°F across sampled records
Relative humidity80–84% on average (driest month about 76%)
Rainfallabout 2399 mm a year

Measured at 48 wild occurrence records sampled against WorldClim 2.1 climate data (1970–2000 averages). Air conditions in the range are ecological context, not enclosure settings: microhabitats such as burrows, leaf litter or basking rocks can be cooler, warmer or more humid.

From the sources

From the sources

Quoted from the matching sections of reputable sources for this exact species. Specialist databases are used first; Wikipedia (community-edited, CC BY-SA 4.0) only fills gaps. Other sources are short credited quotes.

OverviewThe raspy river stingray, mosaic stingray or arraia (Potamotrygon scobina) is a species of freshwater fish in the family Potamotrygonidae. This stingray is endemic to the Amazon basin in Brazil, where known from the Amazon–Pará River (Belém to near the confluence with the Putumayo River), the Madeira River basin, Uatumã River and lower Tocantins River. It reaches up to 69 cm in disc width and 132.5 cm in total length. It is fairly common, but threatened by habitat loss. — Wikipedia (community-edited)
Where it livesHome ranges Population dynamics Growth parameters Max. ages / sizes Length-weight rel. Length-frequencies Mass conversion Recruitment Abundance Life cycle Reproduction Maturity Maturity/Gills rel. — FishBase
ReproductionFecundity: 1-4 pups; gestation takes 3-4 months. — FishBase
Appearance and sizeMaximum length 54.7 cm wd male/unsexed; maximum published weight 15.0 kg. — FishBase

Data and studies

The numbers

The numbers

Each bar is what one source reports. Where several sources weigh in, the dashed gold band marks their average.

Typical adult weight

Reported33.1lb
FishBase 16433.1

Average adult body mass in each database (FishBase gives the maximum recorded weight).

Adult length

Average of sources17.6in
FishBase 16421.5
Seriously Fish species profiles 16713.8

Maximum recorded length. Measured as disc width. Fish in home aquariums often stay smaller than wild records.

Water temperature

Reported75–79°F
Seriously Fish species profiles 16775–79

Range the species tolerates; aim for the middle.

pH

Reported6–7.5
Seriously Fish species profiles 1676–7.5

Water hardness

Reported4–10dGH
Seriously Fish species profiles 1674–10

Minimum tank footprint

Reported71in
Seriously Fish species profiles 16771

Seriously Fish recommends a tank base of at least 71 × 30 in (about 214 US gallons).

Sources for this sheet

  1. FishBase (Froese & Pauly, eds.), version 24.07 Peer-reviewed researchThe global scientific database on fishes, maintained by a consortium of research institutions; every value is referenced.
  2. Seriously Fish species profiles Experienced keeper or breederLong-running aquarium reference written and peer-checked by experienced fishkeepers and ichthyologists; each profile covers habitat, tank size, water, diet, behaviour and breeding.
  3. Species+ (UNEP-WCMC and the CITES Secretariat) Zoo, university or veterinaryThe official database of species listed under CITES.
  4. USFWS International Affairs: CITES Zoo, university or veterinaryFederal agency that issues CITES permits.
  5. Merck Veterinary Manual: Management of aquarium fish Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
  6. Merck Veterinary Manual: Types and features of aquatic systems Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
  7. Merck Veterinary Manual: Nutritional diseases of fish Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
  8. Wikipedia (species article) Community referenceFree encyclopedia; useful overviews with their own citations. Intro text is quoted under CC BY-SA 4.0.