|Genus & Species: Devario Malabaricus
|Common Names: Malabar Danio, Giant Danio
|Temperature: 72 – 81ºF (22 – 27ºC)
|pH: 6.5 – 8.5
|GH: 4.0 – 15 dGH
|Max Size: 10 – 15 cm (3.93 – 5.90 inches) in length
|Lifespan: 6 – 8 years
|Depth Preference: Mid dweller
|Tank Size: 40 gallons
Despite being the more prevalent species in the aquarium trade, malabar danios have repeatedly been mistaken for numerous other Devario species, such as the giant danio (Devario Aequipinnatus).
Origin & Habitat
Malabar danios are a freshwater species of fish endemic to Sri Lanka and India. Originally described from Malabar, India, and now generally accepted to range throughout the southern and western-flowing drainages of India, as well as being common throughout the lowlands and some of the central hills of Sri Lanka.
Kissimmee, the South Atlantic gulf, and Tampa Bay on the southeast Florida coast, as well as Lake Mead, Nevada have all had malabar danio introductions. Reports of malabar danios from Bangladesh have been confirmed to be the giant danio (Devario Aequipinnatus).
They typically inhabit moderately flowing streams and small rivers, where there is overhanging foliage, and highly oxygenated clear water, which has substrates made up of smaller river rocks and an abundance of other rocks of varying sizes.
Malabar Danio Care
Malabar danios are an undemanding species and are easy to care for in well-maintained aquariums. They will flourish in an aquarium that closely resembles their native environment, with a moderate flow and a substrate made up of different-sized river rocks, sand, gravel, and larger rocks.
They thrive in pristine environments and are intolerant to the buildup of ammonia, nitrites, and other pollutants. As a result, they need frequent water changes to maintain highly oxygenated water that is free of contaminants.
Maintaining decent water aeration and weekly water changes of up to 50% of the aquarium’s total capacity should be regarded as standard practice. The tank’s lid must fit snugly due to the malabar danio’s excellent jumping ability.
Malabar Danio Diet & Feeding
In the wild, malabar danios largely consume different kinds of terrestrial arthropods, such as ants that fall into the water, which make up 1/3 of their total diet. They will also frequently scavenge for sources of larvae, detritus, invertebrates, and plant matter.
They are not picky eaters in an aquarium and will readily consume the majority of food that is offered quickly. Due to their well-balanced diet in the wild, it should be standard practice to provide a variety of live, frozen, and dried food sources. This will guarantee that they maintain their best colors and remain healthy.
The bulk of their diet can consist of a high-quality dried product in the form of flakes or pellets, with regular additions of live and frozen food sources. A source of algae like spirulina or other plant matter should be incorporated into their diet once or twice a week because the majority of the plant matter that they consume comes from insects that have recently fed.
The best sources of live, frozen, and dried food that is high in animal protein will include ingredients such as insects, insect larvae, brine shrimp, mysis shrimp, bloodworms, daphnia, and other microworms. Since insects and insect larvae make up the majority of their diet in the wild, an emphasis should be placed on these ingredients.
Due to their high activity level, they require a minimum of two to three feedings each day. To avoid overfeeding, just provide them with enough food that they can consume in one or two minutes.
Tank Mates & Temperament
Malabar danios are relatively peaceful fish, but because of their agility and active eating habits, they may be disruptive to other slow-moving or idle species of fish. Because of this, agile fish of a similar size and temperament will be the best tank mates.
They are a schooling species by nature, so it is best to keep them in large groups of at least 8 – 12 fish. Males usually display more vibrant colors when rivals are present, and maintaining larger schools will assist in reducing their shy behavior often seen in smaller groups. Any aggression will also be suppressed as the malabar danios concentrate on preserving their position in the group’s hierarchy.
The best tank mates for the malabar danio will include species in the families of barbs, south american cichlids, lake tanganyika cichlids, lake malawi cichlids, dwarf cichlids, rasboras, rainbowfish, sunfish, tetras, and other similar species that are not slow-moving or has long-flowing fins such as the siamese fighting fish.
They are an ideal community member for both peaceful, semi-aggressive, and aggressive community tanks that do not inhabit large fish capable of eating them. A large school of malabar danios is a suitable choice to act as dither fish since they are agile, serving as a distraction to prevent one specific fish from being repeatedly targeted by other territorial or aggressive species of fish, which frequently contributes to lowering aggression.
Male & Female Differences
Sexual dimorphism between a younger male and female malabar danio is virtually non-existent until they are fully mature. The underside of females will be of a silver coloration, overall less colorful, and relatively broader. From a dorsal view or top-down perspective, females will be comparatively larger than their male counterparts.
The underside of males will be a mixture of silver and yellow coloration, overall more colorful, and relatively slimmer. From a dorsal view or top-down perspective, males will be comparatively slimmer than their female counterparts.
Breeding & Spawning
Malabar danios are a free-spawning species of fish that scatter their eggs and show no signs of parental care. Usually, between 3:00 and 5:00 in the morning, an adult pair typically spawns during the first hour of dawn. They don’t display a distinct pre-mating or spawning behavior, and their courtship behavior only lasts for a few seconds.
A mature female will lay up to 200 eggs, which are typically 1.05 to 1.08 mm in diameter, somewhat yellowish in color after fertilization, and firmly adheres to any surfaces. The fish fry will begin to hatch 35 to 36 hours after fertilization, and by the fifth day, they are freely swimming.
They will frequently reproduce in a planted, mature aquarium when properly conditioned, and it’s very likely that a bunch of fry may begin to develop naturally without any intervention.
A school of adult malabar danios can be conditioned together, or a more effective approach would be to separate the males and females to allow the females to accumulate a healthy amount of eggs. After conditioning the adults for several weeks on live and frozen insects, insect larvae, and brine shrimp, the females will begin to appear rather plump.
The spawning aquarium should consist of warmer water at the higher end of their suggested range of 81ºF (27ºC) with a neutral pH. A smaller 5-gallon tank or attachable breeding box with no more than 15 cm of water is appropriate because they often spawn in shallow waters.
Whether they are real or synthetic, a few fine-leaved plants or spawning mops spread throughout the base will create acceptable spawning sites for the females to release eggs onto; live plants produce higher levels of dissolved oxygen, which leads to better results.
A minimal amount of eggs will be eaten by the adults if the foundation of the tank is lined with a mesh that allows the eggs to freely fall through but prevents the adults from reaching the eggs.
During the evening, relocate two males and two females into a spawning tank that is dimly lit once the adults have been conditioned and the spawning tank is fully set up. This will give them several hours to unwind and acclimate to their new surroundings before spawning the following morning.
If any eggs are seen at the bottom of the tank, the parents must be removed immediately from the spawning tank to prevent them from eating any of the eggs. Higher oxygen levels will also be provided, which will boost the likelihood that eggs will hatch if an air stone is already in place and is turned on as soon as eggs are noticed.
The fish fry are relatively easy to take care of; starting on the fifth day after hatching, feed them cultured infusoria or baby brine shrimp for the first few weeks so that they grow quickly. Unlike dry or frozen food that decay quickly, live food sources do not rapidly contaminate the water.
If you intend to feed the fish fry with powdered or crushed flake food, you must clean the tank’s substrate following each feeding to prevent the accumulation of decaying organic matter that may result in higher than usual mortality rates.
The majority of older literature incorrectly refers to this species in the aquarium industry as giant danio (Devario Aequipinnatus), but in fact, it is malabar danio (Devario Malabaricus), according to several genetic data analyses.
Devario Aequipinnatus has been described in a large number of publications from India and its neighbors, but its taxonomic position has never been adequately determined. As a result, the name has alternated with Devario Malabaricus as a convenient name for striped Devario species.
While some authors from Sri Lankan such as Munro (1955); Mendis and Fernando (1962) adopted Hora and Nair’s (1941) classification of Devario Malabaricus and Devario Aequipinnatus as one species, others such as Pethiyagoda (1991) paradoxically recognized both Devario Malabaricus and Devario Aequipinnatus as separate species.
Prior to 2003, malabar danios were included in the Danio genus. Fang then studied all of the former Danio species in greater depth, and the findings indicated that the genus Danio had individuals that were not descended from a single common ancestor. The larger species were given the genus name Devario, while the smaller species were given the name Danio.
The combination of the following characteristics sets Devario Malabaricus apart from all other members of the genus: no process on 1st infraorbital; body depth 27–35 %SL; predorsal scales15–17; branched dorsal-fin rays11½–12½; branched anal-fin rays 12½–17½; danionin notch present; dorsal fin origin to hypural distance when carried forward falling well short of the posterior border of the eye; pectoral-fin tip almost reaching pelvic-fin origin when adpressed; snout length subequal to or greater than eye diameter; P stripe originating level with the origin of pelvic-fin, 1–2 scale-widths anterior to dorsal-fin origin; P-1 stripe less than half width of P stripe, bifurcated anteriorly by a more or less broken whitish line; anterior half of body with 5–6 dark, irregular, vertical bars. No nuptial tubercles in both sexes.
T. Rakesh Sharma. Appraisal of seasonal variations in water quality of river Cauvery using multivariate analysis. 2020
Sureni H. Sumathipala, Gayan Nadeela Hirimuthugoda, and Shalika Kumburegama. Reproductive Behavior & Early Development in the Giant Danio, Devario malabaric. 2015
Sven Kullander, Mizanur Rahman, Michael Norén, and Abdur Rob Mollah. Devario in Bangladesh: Species diversity, sibling species, and introgression within danionin cyprinids (Teleostei: Cyprinidae: Danioninae). 2017
Hiranya Sudasinghe, Rohan Pethiyagoda, and Madhava Meegaskumbura. Evolution of Sri Lanka’s Giant Danios (Teleostei: Cyprinidae: Devario): Teasing apart species in a recent diversification. 2020
Sudesh Batuwita, Madura de Silva, and Sampath Udugampala. A review of the genus Devario in Sri Lanka (Teleostei: Cyprinidae), with description of two new species. 2017
Jacobus Vijverberg, Marco van der Land, Albert Vreeke, Bandu Amarasinghe, and Koenraad Kortmulder. Availability of animal food organisms and their utilization by cyprinids in Sri Lankan hill-stream pools. 2019
Hannah Nelson, Gabrielle Coffing, Sarah Chilson, Kamil Hester, Casandra Carrillo, Samantha Ostreicher, Wendy Tomamichel, Samuel Hanlon, Alan Burns, and Pascal Lafontant. Structure, development, and functional morphology of the cement gland of the giant danio, Devario Malabaricus. 2019