Giant Danio

Devario aequipinnatus

The Giant Danio (*Devario aequipinnatus*) is the exact definition of a muscular aquatic torpedo. Similar in shape to a miniature trout, it is one of the most robust, fastest and most massive cyprinids (up to 12-15 cm / 5-6 inches) available in the commercial circuit. Sporting a shiny steel-blue metallic body, intersected by horizontal lines and broken golden dashes, it is a spectacle of pure athletic power. Its schooling swim is so frantic and unstoppable that it transforms any aquarium into a race track. Unfortunately, this colossal kinetic energy makes it unsuitable for 90% of average home aquariums.

Family: Danionidae
Origin: Asia (Torrenti montani veloci e acque trasparenti pedemontane di India, Nepal e Sri Lanka)
Origin: Selective breeding and cultivarsSouth and Southeast Asia
Tank use: Used in 0 tanks

Species challenges

Temperature

22 °C - 26 °C

6.5 - 7.5

Water type

Freshwater

Tank level

Surface and middle

Adult size

15 cm

Description

Geographic Origin and Biotope: Sri Lanka (also in India, but with taxonomic complexities). Populates hill and mountain rivers of crystalline clarity, living exclusively in areas of greatest turbulence and cascades.

Taxonomy and Morphology: Giant Danio (Devario aequipinnatus). The colossus of the Danio family, with a muscular, torpedo-shaped and decidedly deep body. The upper mouth is specialized in grabbing insects on the surface.

Social Behavior: Hyperactive and noisy. Splashes impressively on the surface. Being a school, it must stay in groups of 8 or more. Male hierarchies consist of parallel swimming at very high speed.

Coloration and Sexual Dimorphism: Wears an iridescent blue-green background, with striking and elaborate golden yellow horizontal and reticulated streaks. Females are noticeably faded and larger; males are dazzlingly golden and slender.

Care and observations

Aquarium Setup: This species requires enormous tanks despite its medium size: a 120-150 cm (48-60 inches) tank is the minimum to see them dart without crashing. Use powerful circulation pumps and keep the tank covered.

Diet and Feeding: Incredibly voracious. At feeding time the water literally boils. Excellent flakes for omnivorous fish, granules, but above all aquatic or terrestrial invertebrates, such as waxworms, medium crickets or chopped earthworms.

Water Quality: Oxygenation must be extreme; simulating a stream means having very clean and never stagnant water. Suffers from warm water over 27°C (81°F), which dangerously accelerates its breathing.

Compatibility and Tankmates: Tolerated only by robust Cichlids, Clown Loaches, Labeos and other Asian stream fish. Absolute terror for Discus and Angelfish (who will literally be scared to death by their swimming). A great companion is the Garra flavatra.

Aquarium Reproduction: Very simple in suitable tanks (pebble bottom and strong current). They shoot thousands of free eggs and instantly eat what does not get stuck between the stones. The larvae are large and immediately accept brine shrimp.

Risks and Diseases: Head trauma. Frightened by a shadow or lights suddenly turned on, they dart blindly, crashing to death against the side glass if the tank is too short (<100 cm / 40 inches).

Fish profile

Temperament: Pacifico per indole, ma caotico, prepotente e altamente stressante. Nuota incessantemente sfiorando la superficie dell'acqua, sfrecciando da un capo all'altro. Costituiscono un branco rigido guidato dal maschio alfa.
Diet: Insettivoro/Predatore di superficie. Voracissimi mangiatori onnivori. Aggrediscono la superficie per afferrare scaglie, ma in natura preferiscono insetti caduti. Nutrire con stick galleggianti, grilli liofilizzati e grossi chironomus. Ignorano spesso il cibo che cade sul fondo.
Tank level: Surface and middle
Minimum group: 6
Adult size: 15 cm
Minimum tank: 300 L
GH: 4 dGH - 15 dGH
KH: n/a
TDS: n/a
Conductivity: n/a
Sex ratio: Gruppi misti in branco. I maschi hanno una colorazione blu-acciaio molto più brillante e marcata; le femmine adulte diventano notevolmente gonfie e più rotonde al centro.
Feeding frequency: 1-2 volte al giorno in grandi quantità.
Bioload: Medio-Alto (nuotatori esplosivi, necessitano di molta energia e inquinano in proporzione)
Flow: Corrente Forte (Reofili, amano fare nuoto controcorrente davanti alle pompe)
Jump risk: Covered tank required
Reproduction: Dispersori di uova in acque correnti libere. Le uova non sono adesive e rotolano sul fondo tra i ciottoli di fiume sfuggendo ai genitori. Riprodurli è facile in vasche capienti con biglie di vetro sul fondo, dato l'appetito spietato dei genitori per le proprie stesse uova.
Compatibility: NON INSERIRE con pesci timidi o lenti (come Discus, Gourami o Betta): questi pesci moriranno d'infarto o di stenti (i Danio ruberanno tutto il cibo sulla superficie in un decimo di secondo). Eccezionali pesci 'dither' per enormi Ciclidi Sud/Centro americani (che non riescono a mangiarli per via della stazza e velocità) o grandi Botia Pagliaccio.

Image gallery

Licensed images linked to the species or, when marked, to the closest representative taxon.