Payara (Vampire Fish / Saber-Tooth Barracuda)
Hydrolycus scomberoides
The Saber-Toothed Impaler of the Amazon (30-40 cm / 12-16 inches in captivity). The Payara is quite simply the most terrifying-looking freshwater predator on Earth. It is world-renowned for possessing two colossal, horrific lower fangs (saber-teeth) that grow so long that nature had to biologically carve two hollow 'sheaths' or cavities directly into the fish's upper skull, just to allow the fangs to slide up and hide near its brain when it closes its mouth. Despite its demonic appearance, it is a highly fragile, incredibly skittish, and neurotically stressed fish with an infamously high mortality rate in home aquariums due to its strict demand for industrial water current, easily fractured jaw, and extreme susceptibility to fungal disease.
Water Temperature
24 - 28 °C
pH Value
6 - 7.5
Water type
Freshwater
Tank level
Middle
Adult size
30 cm
Minimum tank volume
>= 300 L
Minimum group
>= 1
GH
4 - 12 dGH
KH
2 - 6 dKH
TDS
80 - 240 ppm
Conductivity
125 - 375 uS/cm
Species description
Geographical Origin and Habitat: Upper Amazon basin (Rio Ucayali, Peru). Open water pelagic predator; stations in fast river currents waiting for small fish to be washed downstream.
Taxonomy and Morphology: Vampire Tetra / Payara (Hydrolycus scomberoides). A legendary "monster" in the aquarium hobby. It possesses two gigantic fangs (lower canines up to 15 cm / 6 inches in adults in the wild) that slide into upper cranial slits (holsters) when it closes its mouth.
Social Behavior: In the tank it is a shy predator (not territorially aggressive). Swims in mid-water tilted downwards, with short and furious bursts to catch prey. Tolerant of similar specimens if there is enough space.
Coloration and Sexual Dimorphism: Metallic scales, silver like mirrors to camouflage in the light of open water (barracuda effect). The belly is slightly shaded, but the two protruding fangs capture all visual attention.
Care, breeding and tankmates
Aquarium Setup: Exhibition aquarium in "River" style. Minimum 180-200 cm (72-80 inches) BARE tank, requires titanic flow pumps running continuously. Furnishings or rocks are dangerous because it injures itself darting in fear.
Diet and Feeding: Feeding nightmare! The Payara will almost always ignore dead foods. When young it needs neons, guppies and minnows (live feeder fish); as it grows it must be slowly weaned (with months of patience) to fish chunks moved by tongs.
Water Quality: Require immaculate filtration and 100% saturated oxygen levels to counterbalance life in constant current. They are terrified of sudden pH drops and cannot stand ammonia.
Compatibility and Cohabitation: Ignores fish that do not fit in its mouth. Strangely cohabits peacefully with shield fish like large Geophagus, large Loricariids, Metynnis (Silver Dollar) and huge peaceful Cichlids (Heros).
Aquarium Breeding: Totally impossible and unknown in captivity (Unrecorded worldwide). The required dimensions and the hormonal trigger of the Amazonian rain migrations preclude their reproduction in the tank.
Risks and Diseases: The "Broken Fang" or panic syndrome. 90% of specimens (grow only 30cm / 12 inches in captivity, compared to 1 meter / 3.3 feet in nature) die young crashing against the glass scared by lights, irreversibly breaking their jaw and fangs.
Geographic Origin and Distribution
Upper Amazon basin (Rio Ucayali, Peru). Open water pelagic predator; stations in fast river currents waiting for small fish to be washed downstream.
Origin
Amazon, Orinoco, and GuianasEast Asia
Fish profile
- Temperament
- Semi-aggressive
- Despite their fearsome appearance and predatory nature, they are surprisingly skittish and easily startled in captivity. Sudden movements or poor water quality can cause them to panic and violently crash into the aquarium glass. They are generally peaceful towards fish too large to eat, but remain dedicated, lethal predators.
- Diet
- Omnivore
- They are obligate piscivores in the wild, using their enormous fangs to spear smaller fish before swallowing them whole. While difficult to transition, some individuals can be trained to eat frozen whole fish like silversides or lancefish. Offering a varied diet of fish, ensuring high protein intake, is crucial for their survival.
- Life expectancy
- 0.5-2 years
- The Payara, or Vampire Fish, has a very challenging survival rate in home aquariums, often living for only 6 months to 2 years due to stress and improper care. Under expert care in massive, highly oxygenated systems, they can survive for up to 3 to 5 years, though they can reach 10 to 12 years in their wild Amazonian habitat. They are extremely sensitive to organic waste, sudden changes in water chemistry, and mechanical injuries from colliding with aquarium glass. Ensuring a stress-free environment and pristine water conditions is critical to extending their captive lifespan.
- Adult size
- 30 cm
- The catalog's scalar value is 30 cm. The FishBase species summary source reports a maximum adult measurement of 117 cm for this species, recorded as total length (TL). The taxonomic record consulted is Hydrolycus scomberoides (live-2026-07-30); male or unsexed record. These figures are not interchangeable: the first is the profile's editorial reference, whereas the second is a published maximum under a specific measurement convention; differences among sources can reflect sex, population, life stage and measuring method.
- Sex ratio
- Pair
- There are no known, visually obvious sexual dimorphisms present in this species. Determining the sex of living specimens is practically impossible without invasive veterinary procedures. Furthermore, keeping groups to establish pairs often ends in severe territorial aggression.
- Feeding frequency
- Twice daily
- Adults typically require feeding only once every two to three days, reflecting their gorge-and-fast natural feeding cycle. Juveniles may require more frequent feedings, usually daily or every other day, to fuel their rapid growth. Careful observation is needed to ensure they are maintaining adequate body weight.
- Bioload
- This apex predator produces an exceptionally high bioload due to its heavy, protein-rich diet. The waste generated from digesting whole fish can quickly degrade water quality if not managed properly. Massive biological filtration, strong mechanical flow, and stringent water change schedules are strictly required.
- Flow
- Stagnant
- They absolutely require strong, highly oxygenated water currents to mimic their natural fast-flowing river habitats. Powerful powerheads and extensive aeration are essential to keep these fish healthy and thriving. Inadequate flow or low oxygen levels will rapidly lead to stress, disease, and death.
- Reproduction
- Oviparous
- Successful captive breeding of this species has not been documented in the home aquarium hobby. They require enormous spaces and specific seasonal river flooding triggers that are impossible to replicate in standard tanks. All specimens available in the trade are wild-caught from their native river systems.
- Compatibility & tankmates
- They are highly predatory and possess an extremely large mouth equipped with massive, specialized fangs. Any fish that can even remotely fit into their mouth will be viewed as prey and consumed. They are best kept alone or with armored, deep-bodied fish that are far too large to be swallowed.
- Tank level
- Middle
- They generally occupy the middle to upper levels of the water column, hovering against the strong current. They are built for open water ambush, waiting for unsuspecting prey to drift by before striking with lightning speed. They rarely rest on the substrate, requiring plenty of unobstructed swimming space.
Scientific Parameters & Models
FishBase
Window to the official scientific data of the species
Data synced on: 06/15/2026
- Trophic level
- 4.5 ± 0.5 se
- Phylogenetic uniqueness (PD50)
- 0.5664
- Bayesian Length-Weight
- a = 0.00661, b = 3.2
- VulnerabilityHigh to very high vulnerability (70 / 100)
Image gallery
Licensed images linked to the species or, when marked, to the closest representative taxon.
Related species
Recommendations grouped by close relatives, companion choices, and similar care.
