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No federal permit to keep

Inspector Catfish

Hypancistrus inspector

Also known as Snowball Pleco

Fishes › Catfish (Siluriformes) › Loricariidae (Plecos)

Hypancistrus inspector is a species of freshwater ray-finned fish belonging to the family Loricariidae, the suckermouth armoured catfishes, and the subfamily Hypostominae, the suckermouth catfishes.

Aquarium hobby
Experience: Easy
FamilyPlecos
Adult lengthup to 6.3 in
WaterFreshwater
HabitatLives in freshwater

Care at a glance

Species-specific aquarium care

  • Tank: At least 24 in long and 12 in front to back for one adult (adults commonly reach about 5.0 in / 12.59 cm).
  • Water: Freshwater.
  • Layout: Uses both the bottom and open water: give open swimming space plus cover near the substrate.
  • Diet: FishBase classes it as a herbivore.
  • 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 47 × 18 in (roughly 64 US gallons); space needed is rated “large tank”.
  • Water: a fairly wide range, from slightly acidic to slightly alkaline, 72–86 °F, pH 5–7.5, 1–15 dGH.
  • Behaviour: temperament peaceful; a shoaling fish best kept in a group of six or more; not a community fish.
  • Difficulty: Moderate (Seriously Fish rating).

Short excerpts from the species profile:

  • Setup: “Best maintained in an aquarium designed to simulate a flowing stream with a substrate of variably-sized rocks, sand, fine gravel, and some water-worn boulders.”
  • Diet: “Wild specimens are probably omnivorous but with a preference for aquatic invertebrates and other small animals.”
  • Tankmates: “A peaceful species which can be maintained in a well-chosen community, but should not be maintained alongside other Hypancistrus spp.”

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

Group care guide

Plecos (suckermouth catfish)

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.

Common aquarium bristlenoses are frequently unidentified Ancistrus stocks sold under “cirrhosus”. Verify identification before importing a common-bristlenose care sheet into the true A. cirrhosus record.

Housing & setup

  • Driftwood (some species rasp it for fiber), caves and good flow.
  • Common plecos reach 18–24 in; many smaller species stay under 6 in.

Sources 117119164118266

Diet

  • Algae wafers and vegetables for herbivores; meaty foods for carnivorous species.

Sources 117119164118266

Health watch

  • Starvation if they're expected to live on algae alone.

Sources 117119164118266

Understanding the animal

This species is part of a group that hobbyists, aviculturists or zoos keep widely (Plecos), 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 catfish occurs in the upper Orinoco basin of Colombia and Venezuela, and in the basin of the Rio Negro in Brazil. This species reaches a standard length of 12.6 cm (5.0 in).

Quoted from the Wikipedia article “Hypancistrus inspector” (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, in rivers and streams. Uses both the bottom and open water. Specimens collected from rocks and rapids. Stomach contents include algae and detritus; also seeds (dicotyledonous and monocotyledonous seeds).
Water it lives inFreshwater.
ClimateTropical climate.
Behavior to plan forBreeding: clutch tenders.
  1. FishBase species summary: Hypancistrus inspector
Native climate (measured)

Native climate (measured)

Warm-season highsabout 89°F (up to 95°F in the hottest sampled areas)
Cool-season lowsabout 69°F (down to 69°F in the coldest sampled areas)
Average temperature78–81°F across sampled records
Relative humidity82–85% on average (driest month about 82%)
Rainfallabout 3072 mm a year, spread fairly evenly

Measured at 11 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.

OverviewHypancistrus inspector is a species of freshwater ray-finned fish belonging to the family Loricariidae, the suckermouth armoured catfishes, and the subfamily Hypostominae, the suckermouth catfishes. This catfish occurs in the upper Orinoco basin of Colombia and Venezuela, and in the basin of the Rio Negro in Brazil. This species reaches a standard length of 12.6 cm. This species is found in the aquarium trade where it is known as the snowball pleco or by the number L102. — 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
ReproductionFemale deposits the eggs in caves; male defends the spawning place. — FishBase
BiologySpecimens collected from rocks and rapids. Stomach contents include algae and detritus; also seeds (dicotyledonous and monocotyledonous seeds). — 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.

Adult length

Average of sources5.7in
FishBase 1645
Seriously Fish species profiles 1676.3

Maximum recorded length. Measured as standard length (snout to the base of the tail, not counting the tail fin). Fish in home aquariums often stay smaller than wild records.

Water temperature

Reported72–86°F
Seriously Fish species profiles 16772–86

Range the species tolerates; aim for the middle.

pH

Reported5–7.5
Seriously Fish species profiles 1675–7.5

Water hardness

Reported1–15dGH
Seriously Fish species profiles 1671–15

Minimum tank footprint

Reported47in
Seriously Fish species profiles 16747

Seriously Fish recommends a tank base of at least 47 × 18 in (about 64 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. Merck Veterinary Manual: Management of aquarium fish Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
  4. 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.
  5. Merck Veterinary Manual: Nutritional diseases of fish Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
  6. Seriously Fish — Ancistrus sp. “3” / common bristlenose identification Zoo, university or veterinaryAdded in the 2026 source-checked care-guide review.
  7. Wikipedia (species article) Community referenceFree encyclopedia; useful overviews with their own citations. Intro text is quoted under CC BY-SA 4.0.