Neohomaloptera johorensis (HERRE, 1944)

Etymology

Neohomaloptera: from the Greek neos, meaning ‘new, young’ (used here as a prefix), and and the generic name Homaloptera, of which Neohomaloptera was originally considered a subgenus.

johorensis: named for the Malaysian state of Johor, from where the type series of this species was collected.

Classification

Order: Cypriniformes Family: Balitoridae

Distribution

Described from a brook near the town of Simpang Renggam, Kluang district, Johor state, southern Peninsular Malaysia and since recorded from the Endau River system, also in Johor, plus the North Selangor peat swamp forest, Selangor state and Perak state in the north west of the country.

This suggests it originally had a wider distribution in the now massively degraded peat swamp forests of Peninsular Malaysia.

Specimens collected from the Kapuas River basin, Kalimantan Barat (West Kalimantan), Indonesian Borneo have also been identified as N. johorensis although a similar-looking fish from the Batang Hari drainage, Jambi province, Sumatra was diagnosed as having different body colour and a longer nasal barbel by Tan and Kottelat (2009).

The latter was listed simply as N. ‘sp.’.

Habitat

Most often inhabits peat swamps and associated black water streams as well as other still waters, often in areas with submerged grasses or aquatic plants and dense riparian vegetation.

The water itself is typically stained brown with humic acids and other chemicals released by decaying organic material, dissolved mineral content is generally negligible and pH  as low as 3.0 or 4.0.

Substrates are usually littered with fallen leaves, branches and submerged tree roots though in some places aquatic plants from genera such as Cryptocoryne or Barcalaya can be found.

In the North Selangor peat swamp, Peninsular Malaysia, this species occurs alongside numerous other fishesincluding Rasbora cephalotaenia, R. einthovenii, R. kalochroma, Trigonopoma gracile, ‘Puntius‘ hexazona, ‘P.‘ johorensis, Kottelatlimia pristes, Nemacheilus selangoricus, Hemirhamphodon pogonognathus, Betta bellica, B. livida, Parosphromenus harveyi, Sphaerichthys osphromenoides, and Trichopodus trichopterus.

Maximum Standard Length

17 – 25 mm.

Aquarium SizeTop ↑

An aquarium with base measuring 45 ∗ 30 cm or more is recommended.

Maintenance

Most importantly the water must be well-oxygenated and free of organic pollutants, though torrent-like conditions are unnecessary. Use a combination of filter outlets, small powerheads, air stones, etc. to achieve the desired effect.

A soft, sandy substrate is preferable, to which can be added driftwood roots and branches, dried leaf litter and aquatic plants able to survive under such conditions such as Microsorum, Taxiphyllum and Cryptocoryne spp.

Ensure that small specimens are unable to enter filter intakes and cover the tank well as most loaches do jump at times, especially when first introduced.

Since it requires stable water conditions this loach should never be added to biologically immature set-ups.

Water Conditions

Temperature: 23 – 26 °C

pH: 3.5 – 6.5

Hardness: 0 – 90 ppm

Diet

This species is a specialised grazer feeding on biofilm, small crustaceans, insect larvae and other invertebrates in nature.

In captivity some sinking dried foods may be accepted but regular meals of live or frozen Daphnia, Artemia, micro worm, grindal worm, etc., are essential for maintenance of good health, and it’s highly preferable if the aquarium contains solid surfaces with growths of algae and other aufwuchs.

Balitorids are often seen on sale in an emaciated state which can be difficult to correct.

A good dealer will have done something about this prior to sale but if you decide to take a chance with severely weakened specimens they’ll initially require a constant source of suitable foods in the absence of competitors if they’re to recover.

Behaviour and CompatibilityTop ↑

Very peaceful but its environmental requirements and adult size limit the choice of suitable tankmates.

Peaceful, diminutive schooling cyprinids such as Boraras, Trigonostigma, and Sundadanio spp. are ideal, and if geography isn’t an issue many smaller, blackwater-dwelling characins should also work.

Other loaches could include Pangio, Acanthopsoides or smaller Lepidocephalichthys spp.

From the limited information available it appears this species is peaceful both with conspecifics and other fishes and there exist no reports of it harming tankmates though eggs and fry may be preyed upon.

It seems to fare best when maintained in numbers and should ideally be kept in a group of 4 or more specimens.

Sexual Dimorphism

Sexually mature females should be a little larger and fuller-bodied than males.

Reproduction

Presumably a seasonal spawner in nature but nothing has been recorded in aquaria as far as we know.

NotesTop ↑

We’re unsure if this species has ever been traded on a commercial basis though it has been maintained by a few private collectors.

It’s difficult to confuse with any other balitorid due to the small adult size and distinctive orange to reddish-brown body colouration.

Neohomaloptera was originally erected by Herre (1944) as a monotypic subgenus of Homaloptera for the subject species.  Silas (1953) assigned it full generic status. It was later syonymised with Homaloptera by Alfred (1969) but has been generally accepted as a genus in its own right since Roberts (1989).

The chief distinguishing characters separating it from Homoloptera are possession of two pairs of maxillary barbels (vs. 1), low pectoral-fin ray counts (11-12, vs. 13-18) and 31-37 lateral line scales, less than all Homaloptera spp. except H. tweedei which has 32-36. The genus remains monotypic to date.

N. johorensis is sometimes referred to as ‘lizard loach’ due to its behaviour and appearance.

It has morphology specialised for life in fast-flowing water, i.e., the paired fins are orientated and extended horizontally, head and body flattened, belly depressed.

These features form a powerful sucking cup which allows the fish to cling tightly to solid surfaces. The ability to swim in open water is greatly reduced and they instead appear to crawl and hop their way over rocks and other surfaces.

The family Balitoridae as recognised by Kottelat (2012) is widely-distributed across much of the Indian subcontinent, Southeast Asia and China.

Kottelat (2012) also considers the family Gastromyzontidae valid and many former balitorids are now contained within that group, but Neohomaloptera is retained in Balitoridae.

References

1. Herre, A. W. C. T., 1944 - Proceedings of the Biological Society of Washington 57: 45-51
   Notes on fishes in the Zoological Museum of Stanford University. XVII. New fishes from Johore and India.
2. Alfred, E. R., 1969 - Zoologische Mededelingen 43(18): 213-237
   The Malayan Cyprinoid fishes of the family Homalopteridae.
3. Kottelat, M., 2012 - Raffles Bulletin of Zoology Supplement 26: 1-199
   Conspectus cobitidum: an inventory of the loaches of the world (Teleostei: Cypriniformes: Cobitoidei).
4. Kottelat, M., 2013 - Raffles Bulletin of Zoology Supplement 27: 1-663
   The fishes of the inland waters of southeast Asia: a catalogue and core bibliography of the fishes known to occur in freshwaters, mangroves and estuaries.
5. Ng, H. H. and H.-H. Tan, 1999 - Zoological Studies 38(3): 350-366
   The fishes of the Endau drainage, Peninsular Malaysia with descriptions of two new species of catfishes (Teleostei: Akysidae, Bagridae).
6. Roberts, T. R., 1989 - Memoirs of the California Academy of Sciences No. 14.: i-xii + 1-210
   The freshwater fishes of western Borneo (Kalimantan Barat, Indonesia).
7. Tan, H. H. and M. Kottelat, 2009 - Ichthyological Exploration of Freshwaters 20(1): 13-69
   The fishes of the Batang Hari drainage, Sumatra, with description of six new species.
8. Tang, Q., H. Liu, R. Mayden and B. Xiong, 2006 - Molecular Phylogenetics and Evolution 39(2): 347-357
   Comparison of evolutionary rates in the mitochondrial DNA cytochrome b gene and control region and their implications for phylogeny of the Cobitoidea (Teleostei: Cypriniformes).
9. Šlechtová, V., J. Bohlen and H. H. Tan, 2007 - Molecular Phylogenetics and Evolution 44(3): 1358-1365
   Families of Cobitoidea (Teleostei; Cypriniformes) as revealed from nuclear genetic data and the position of the mysterious genera Barbucca, Psilorhynchus, Serpenticobitis and Vaillantella.