Puntius arulius

Cyprinidae

Native to India where it has been recorded from upper parts of the river Cauvery basin in the southern state of Karnataka and Wayanad district, Kerala state. According to Pethiyagoda and Kottelat (2005) the fish appears to be restricted to areas above the original type locality of Srirangapatna in the Cauvery due to damming of the river.

The fish from Kerala are known to possess a comparitively high amount of red scaling on the flanks and belly and in the aquarium are more aggressive towards one another than those from Karnataka. The latter lack red colouration on the body, appearing darker overall with proportionately larger eyes.

No precise data is available but presumably it is a riverine species.

Expect it to reach at least 4"/10cm.

It´s a particularly active species and a group would need a tank measuring at least 48" x 12" x 12"/120cm x 30cm x 30cm/108 litres.

Fairly undemanding provided its tank is well-maintained. It can appear a little washed out in very sparsely decorated set-ups though. A combination of good lighting and a darkish substrate will encourage it to show its best colours. It seems to do best in very clean, well-oxygenated water with a degree of flow and can look quite superb in a set-up decorated with smooth rocks, twisted roots and live plants.

66 - 77°F/19 - 25°C

6.0 - 7.0

2 - 10°H

Like many barbs it's a generalised omnivore in nature feeding on a variety of worms, insects, crustaceans, plant matter and other organic debris. In the aquarium it's just as easily-fed and will greedily accept just about anything offered. For the best condition and colours offer regular meals of small live and frozen foods such as bloodworm, Daphnia and Artemia along with good quality dried flakes and granules.

This species makes an ideal addition to a peaceful community of slightly bigger southeast Asian species such as other similarly sized Puntius, larger rasboras and danionins, botiine loaches and gouramis of the genus Trichogaster. If geography is not an issue it can actually be combined with most peaceful fish of a size too large to be considered food and that have a bold enough disposition to not be intimidated by its size and active nature.

It's a schooling species by nature and really should be kept in a group of at least 8-10 specimens. Maintaining it in decent numbers will not only make the fish less skittish but will result in a more effective, natural looking display. Any aggressive behaviour will normally also be contained as the fish concentrate on maintaining their hierarchical position within the group.

Unconfirmed although as with most barbs the the female is likely to be the thicker bodied sex.

May not yet have been bred intentionally in the hobby although at least one accidental spawning has occured. We suggest adopting an approach that has proven successful for other barbs in the P. filamentosus  group as a starting point. You'll need to set up a separate tank if you want to raise any numbers of fry, with something around 36" x 12" x 12" in size usually recommended. This should be very dimly lit and contain clumps of fine leaved plants such as Java moss or Myriophyllum (spawning mops could also be used) to give the fish somewhere to deposit their eggs. Alternatively you could cover the base of the tank with some kind of mesh. This should be of a large enough grade so that the eggs can fall through it but small enough so that the adults cannot reach them. The water should be of around neutral pH, gH <8, with a temperature of around 75 - 80°F. A small air-powered sponge filter bubbling away very gently is all that is needed in terms of filtration.

Related species can be spawned in a group with half a dozen specimens of each sex being a good number. Condition these with plenty of small live foods and spawning should not present too many problems. Depending on your set-up simply check the spawning medium or tank base each morning for eggs.

Alternatively try spawning it in pairs. Under this technique the fish are conditioned in male and female groups in separate tanks. When the females are noticeably full of eggs and the males are displaying their best colours select the fattest looking female and best coloured male and transfer them to the spawning tank in the evening. They should spawn the following morning. Be sure to provide plenty of cover for the female as the male may be quite aggressive in his pursuit of her. In some cases she may even require a period of rehabilitation in a tank that does not contain any males.

In either situation the adults will probably eat the eggs given the chance and should be removed as soon as any are noticed. These should hatch in 24 - 48 hours with the fry becoming free swimming 24 hours later. They should be fed on an infusoria-type food for the first few days, until they are large enough to accept microworm or Artemia nauplii.

Puntius arulius has recently been the subject of a debate regarding its true identity. "Puntius arulius" has been a popular aquarium fish for many years but a 2005 revision of the so-called P. filamentosus  group by Maurice Kottlelat and Rohan Pethiyagoda appears to suggest a case of mistaken identity. This group contains a handful of south Indian and Sri Lankan barb species that share similar morphological characteristics and currently contains Puntius arulius, P. assimilis , P. exclamatio, P. filamentosus , P. singhala, P. srilankensis and P. tambraparniei . The distinguishing features of Puntius arulius were given as follows in the paper:

"Adults of Puntius arulius are distinguished from P. filamentosus , P. singhala and P. assimilis  by having prominent black markings on body anterior to anal-fin origin. They differ from P. exclamatio by lacking an elongate, tear-shaped black blotch above anal fin. Puntius arulius differs from P. srilankensis by having mouth subterminal and lower lip entire (vs. mouth inferior and lower lip medially absent). It differs from P. tambraparniei  by lacking branched dorsal-fin rays elongated into filaments in adult males (vs. present) and by having a pair of maxillary barbels <0.5% SL (vs. 2.4-4.7%)."

This description was clearly at odds with the fish we have long known as "Puntius arulius" as males develop magnificent trailing filaments in the dorsal fin and have quite long maxillary barbels.

As it happened the paper was published soon after the UK had received imports of an arulius-type fish that was being sold as P. tambraparniei . This was a recent introduction to the hobby and is another of the species in the P. filamentosus  group covered by Kottelat and Pethiyagoda. According to them males of this species do exhibit extended dorsal filaments as well as having comparitively long maxillary barbels. It therefore appears that the fish sold for decades as Puntius arulius is in fact P. tambraparniei  and the recently imported P. tambraparniei  are the 'real' Puntius arulius.

Puntius arulius can thus be considered a rare species in the hobby with all those fish on sale as "Arulius barb" likely to be P. tambraparniei . There is also a third very similar species, the much rarer (possibly endangered) P. srilankensis. This one has the extended dorsal filaments in males but has an inferior mouth (as opposed to subterminal in the other two) making part of the lower lip invisible when the mouth is closed.

The genus Puntius is currently viewed as something of a catch-all for well over 100 species of small cyprinid. Most experts agree that a full revision is required with the likely outcome that many species will be placed into new or different genera. When describing the genus in 1822 Hamilton identified the defining characteristics as: "absence or presence of maxillary only or rostral and maxillary barbels; dorsal fin with last simple ray serrate or entire, branched rays usually 8; anal fin with last simple ray entire, branched rays usually 5; lateral line complete or incomplete, lateral-line scales 17-36 in row; cephalic cutaneous papillae minute or absent; pharyngeal teeth in 3 rows, usually 2,3,5/5,3,2; colour pattern extremely variable." All the species currently in the genus are native to Southeast Asia, India and Sri Lanka.

The other main source of confusion with Puntius is that some authors do not recognise all the member species as such, rather following Walter Rainboth (1996) and preferring to place some into the alternative genus Systomus. Rainboth proposed that Systomus should be reinstated (it was first erected in the 19th century) as a valid genus on account of the fact that in its current state Puntius would seem to constitute a polyphyletic grouping i.e. not all of its members appear to have descended from the same common ancestor. The defining characteristics of a Systomus species are (according to Rainboth) a serrated (vs. smooth in Puntius) dorsal spine, the presence of 2 or 4 barbels (vs. always 2) and less than 12 gill rakers (vs. 12-20). SF tentatively lists all species as Puntius at present.

Literature cited

1. Pethiyagoda, R. and M. Kottelat. - Raffles Bull. Zool. Suppl. 12:127-144. 2005
   A review of the barb of the Puntius filamentosus group (Teleostei: Cyprinidae) of southern India and Sri Lanka.
2. www.petfrd.com
3. www.fishbase.org