Dwarf panchax
Aplocheilus parvus
A small surface-dwelling killifish native to the coastal wetlands of Sri Lanka and southeastern India, adapted to both freshwater and slightly brackish conditions. A translucent olive body with golden reflections and upturned mouth perfectly built for hunting surface insects. Often confused with larger Aplocheilus species, it is genetically distinct and an ideal candidate for tropical nano tanks. A diurnal insectivore, it accepts dry food in the aquarium but live prey remains the cornerstone of its diet.
Water Temperature
22 - 26 °C
pH Value
6 - 7.5
Water type
Freshwater / Brackish
Tank level
Surface
Adult size
4.5 cm
Minimum tank volume
>= 40 L
Minimum group
>= 4
GH
3 - 12 dGH
KH
1 - 6 dKH
TDS
55 - 240 ppm
Conductivity
86 - 375 uS/cm
Species description
Geographical Origin and Habitat: Originating from the coastal rivers and streams of southern India (Tamil Nadu) and Sri Lanka. Inhabits shallow pools and oxbow lakes thickly covered with vegetation along the banks, in fresh to weakly brackish waters.
Taxonomy and Morphology: Dwarf Panchax (Aplocheilus parvus). The smallest ("parvus") representative of the Aplocheilus genus. A micro-pike with a pointed snout, flat back and a peculiar bright silver spot placed right on top of the head (parietal eye).
Social Behavior: Ambush micro-predator, stations motionless a few millimeters below the water surface. Males can have harmless skirmishes with each other for the best hunting stations. Needs a group of at least 6 individuals to diffuse tensions.
Coloration and Sexual Dimorphism: Pastel shades, with an olive back and bright yellowish-green flanks. Males show red or orange edges on the anal and dorsal fins. Females are more faded and present some thin dark bands along the body.
Care, breeding and tankmates
Aquarium Setup: 50-60 cm (20-24 inches) nano-aquarium with an escape-proof sealed lid. The mandatory layout involves thick covers of floating plants (Limnobium) to reassure them. The water level can be slightly lowered to allow surface hunting.
Diet and Feeding: Strictly surface insectivore. Requires wingless drosophila (fruit flies), springtails, brine shrimp nauplii and very fine crushed flakes. If the food falls beyond the upper water column, it will be totally ignored.
Water Quality: Tolerates an exceptionally wide range of values (being present also in extreme estuary areas). Does well in normal dechlorinated tap water (pH 6.5-7.5). Appreciates the addition of catappa leaves but is not strictly necessary.
Compatibility and Cohabitation: Being very small, unlike its cousin A. lineatus, it is not a threat to most tankmates (except Caridina zoeae). Cohabits excellently with microrasboras, Pygmy Corydoras and Dario dario in quiet tanks.
Aquarium Breeding: Reproduces daily by scattering 3-5 adhesive eggs among the roots of floating plants or on artificial mops. The parents rarely prey on the fry if well fed, allowing the hatching and growth of the young in the main tank ("colony breeding").
Risks and Diseases: Very tough fish. The greatest danger comes from overcrowding of the surface or from fast companions (e.g. Danio) that devour all the food before the parvus, a static hunter, can feed, leading it to starvation.
Geographic Origin and Distribution
Originating from the coastal rivers and streams of southern India (Tamil Nadu) and Sri Lanka. Inhabits shallow pools and oxbow lakes thickly covered with vegetation along the banks, in fresh to weakly brackish waters.
Origin
South and Southeast Asia
Fish profile
- Temperament
- Semi-aggressive
- Aplocheilus parvus is a generally peaceful, albeit shy, species that does well in a quiet community tank. However, they possess a strong predatory instinct suited to their size and will actively hunt any organisms small enough to fit into their mouths, including fry or tiny shrimp. Males can be territorial toward rival males, engaging in minor displays, but rarely cause physical harm if enough space is provided.
- Diet
- Carnivore
- As specialized surface predators, Aplocheilus parvus primarily feed on insects and other invertebrates in the wild. In captivity, they will accept high-quality dry flakes and granules, but their diet should be heavily supplemented with live or frozen foods. Offerings such as baby brine shrimp, Daphnia, bloodworms, and wingless fruit flies are highly recommended to promote color, vigor, and breeding behavior.
- Life expectancy
- 3-5 years
- Under optimal care, stable water parameters, and a high-quality diet, Aplocheilus parvus typically has a lifespan of 3 to 5 years in captivity. Although they are not seasonal annual killifish, they are relatively delicate and sensitive to sudden water changes, which can shorten their life expectancy. Ensuring excellent water quality and a low-stress environment is key to helping them reach their maximum lifespan.
- Adult size
- 4.5 cm
- The catalog's scalar value is 4.5 cm. The FishBase SPECIES table (v25.04 snapshot) source reports a maximum adult measurement of 6.25 cm for this species, recorded as total length (TL). The taxonomic record consulted is Aplocheilus parvus (v25.04); 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
- Harem
- Aplocheilus parvus can be kept in pairs (one male and one female) or in small groups (harem style) where females outnumber males. Males can be territorial and display mild aggression towards each other, so keeping a ratio of one male to two or three females helps distribute any potential tension. In larger tanks with plenty of cover, multiple males can be housed together as long as there is enough visual structure to establish distinct territories.
- Feeding frequency
- Twice daily
- To match their active surface-hunting lifestyle, Aplocheilus parvus should be fed small portions once or twice daily. It is important to feed only what they can consume within a minute, as any food that sinks to the bottom will often be ignored and decay, spoiling the water quality. Varying the food types between commercial dry foods and live/frozen options throughout the week ensures balanced nutrition.
- Bioload
- Low
- Being a dwarf species that typically reaches only 3 to 4 cm in length, Aplocheilus parvus has a very low biological footprint. However, they require clean, well-oxygenated water with stable parameters to thrive. A sponge filter or a gentle hang-on-back filter is ideal as it provides efficient biological filtration without creating strong currents that could stress these surface-oriented fish. Regular partial water changes are essential to keep nitrate levels low.
- Flow
- Strong
- This species strongly prefers still or slow-moving water conditions, mimicking their natural habitats of mangrove swamps and rice paddies. High water currents can quickly exhaust these small fish and cause chronic stress, making them susceptible to diseases. Filtration should be adjusted to a weak flow, and the use of baffle devices or dense floating plants is recommended to create calm zones at the surface.
- Jump risk
- Yes
- Like all killifish, Aplocheilus parvus is an exceptional jumper capable of leaping through even the smallest openings in the tank cover. A tight-fitting lid or cover glass is absolutely mandatory to prevent them from jumping out of the aquarium. Additionally, incorporating floating plants such as Salvinia or duckweed reduces their urge to jump by providing a natural cover and security at the surface.
- Reproduction
- Oviparous
- Spawning Aplocheilus parvus is relatively straightforward and not considered difficult. They are continuous spawners, depositing a few eggs daily among fine-leaved plants, mosses, or spawning mops. Eggs hatch in 10 to 15 days depending on water temperature; the parents do not care for the fry and may eat them, so separating the eggs or using a dedicated breeding tank is recommended. The tiny fry require infusoria initially before moving onto Artemia nauplii.
- Compatibility & tankmates
- Peaceful
- Due to their small size and shy nature, Aplocheilus parvus is best kept in species-only setups or community tanks with peaceful, similarly sized companions. Good tank mates include small rasboras, danios, tetras, and peaceful bottom-dwellers like Corydoras. Avoid housing them with aggressive cichlids, fin-nippers, or very large fish that might prey on them, as well as tiny dwarf shrimp, which could become a snack for these micro-predators.
- Tank level
- Top
- This species is strictly a surface-dwelling fish, spending almost all of its time in the top layer of the water column. Anatomically adapted with a flat dorsal surface, upward-pointing mouth, and eyes situated high on the head, it is designed to scan the water surface for prey. The presence of floating plants is highly appreciated as it provides cover and mimics their natural habitat where they linger just beneath the surface.
Scientific Parameters & Models
FishBase
Window to the official scientific data of the species
Data synced on: 06/15/2026
- Trophic level
- 3.5 ± 0.45 se
- Phylogenetic uniqueness (PD50)
- 0.5079
- Bayesian Length-Weight
- a = 0.00389, b = 3.12
- VulnerabilityLow vulnerability (10 / 100)
Image gallery
Licensed images linked to the species or, when marked, to the closest representative taxon.
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