Common name: Arulius Barb, Tamiraparani Barb, Silas Barb, Longfin Barb
Scientific name: Puntius arulius
Synonyms: Barbus arulius
Size: 12 cm / almost 5 inches
pH: 6.0- 8.0
Temperature: 19-25° C (66-77°F)
Hardness: tolerates most conditions

The Arulius barb is a large fast moving barb. It originates from India where it is found in the Tambraparni River basin. This is a comparatively small river basin in the state of Tamil Nadu in southern India. Most if not all Arulius barbs in the trade today are farmed in commercial farms for the ornamental fish trade.

It is possible that the species that we know in the trade as Puntius arulius isn’t the true Puntius arulius. There are a number of similar species living in India and Sri Lanka all belonging to the so called P. filamentosus group. The group was revised in 2005 which resulted in some species earlier considered sub-species becoming true species. Species similar to Puntius arulius includes P. assimilis, P. exclamatio, P. filamentosus , P. singhala, P. srilankensis and Puntius tambraparniei. It is possible that the fish sold in trade as Puntius arulius in reality is one of these species. The true Puntius arulius is scientifically described as "lacking branched dorsal-fin rays elongated into filaments in adult males" and having short maxillary barbells. This does as you can hear not sound as the species we are use to in the trade. The fish that are sold as Pontius arulius in the trade are most likely Puntius tambraparniei. The true Puntius arulius are likely very rare in aquariums.

All the species mentioned earlier can be kept in a similar way so the distinction is not overly important for the individual fish keeper as long as hybridization is avoided.  If your species has an elongated dorsal fin rays and is bought as “Arulius barb”you most likely have a member of the species Puntius tambraparniei.

Aquarium & care

The Aurulius barb is a very hardy species that will adapt to most aquarium conditions as long as the water quality is kept high. It does however show a more vivid coloration in aquariums that contain at least a few hiding places. The aquarium should ideally be decorated in such a way that there are areas with dense vegetation as well as open areas for this fast moving fish to swim around in. A few shaded regions among roots are also appreciated.

Filtration is important when keeping Aurulius barb. The wild fish lives in streams and the Aurulius barb will therefore prefer a well circulated aquarium with oxygen rich water.

This species is the ideal choice for any community aquarium containing mid-size species that appreciate the same environment. Aurulius barbs will not harm or harass fish that are too big to eat. They should however not be kept with timid species that might be spooked and/ or stressed by this fast moving species.

Aurulius barb is a shoaling species and it should always be kept in shoals of 8 or more fish. If they are kept in smaller groups they will not feel secure and will not show their true colors. They might harass other fish species if kept in too small groups.

Feeding Arulius Barb

The Arulius barb is very easy to feed and will ferociously devour any food that is given to it. In the wild they are omnivores feeding on both meaty foods and plants. In aquariums their diet can be based around flake food as long as the diet also includes frozen and live food as well as vegetables. They will survive on flake food only but will not show their true colours and their immune system can also become weakened.

Sexing Arulius Barb

Adult males in spawning condition show white spots around the mouth. This can look like a disease but if the spots are focused around the mouth only it is probably just the spawning dress of this species. Arulius barb is harder to sex when dealing with younger fish and fish that aren’t ready to spawn. Males are however usually more colourful and more slender than the rounder and duller looking females.

Breeding Arulius Barb

Breeding the Arulius barb is easy. This is a large species and the breeding aquarium therefore needs to be quite large. I would recommend nothing smaller than a 20 gallon /  75 L aquarium. Cover the bottom of the tank with marbles or a mesh that protects the eggs from the hungry eyes of their parents. The aquarium should also contain fine leafed plants and java moss. If you don’t want to use live plants you can use spawning mops. Dimmed lighting helps trigger spawning. The water conditions are not that important but neutral water (pH 7) and a temperature around 75 - 80°F / 24-26 (27)°C is ideal.

This species can be spawned in pairs or in groups. If you want to spawn it in groups you condition the group in the breeding aquarium by giving them lots of live and frozen food. Remove the fish from the aquarium once you see eggs. If you want to breed the species in pairs you separate the males and females from each other and condition each group separately with plenty of live and frozen food. Once they are conditioned you choose one male and one female and move them into the spawning aquarium. It is advisable to choose the fattest female and the most colourful male. Remove the pair from the tank once spawning is completed. Arulius barbs do not show any parental care and will eat their own eggs and fry.

Arulius barb eggs hatch after 24 to 48 hours. At really high temperatures they can hatch after 18 hours. The fry become free swimming about 24 hours after hatching. Arulius barb fry are every small and need to be feed infusorians during their first days. They should be large enough to accept newly hatched brine shrimp after one week but it can sometimes take longer.