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Lepidocephalichthys jonklaasi (DERANIYAGALA, 1956)

SynonymsTop ↑

Lepidocephalus jonklaasi Deraniyagala, 1956


Order: Cypriniformes Family: Cobitidae


Endemic to Sri Lanka with type locality ‘shaded pools of mountain streams at Akuressa, Southern Province, Sri Lanka, elevation 500 meters’.

It’s known from at least five localities, all of which are located in restricted to Sri Lanka’s ‘wet zone’ in the southwest of the island, with records existing from the Gin, Kalu, Nilwala, and Bentota river basins plus a small blackwater creek near the Kottawa Forest Reserve, a small, isolated patch of forest in the island’s Southern Province.

As a result of this limited distribution and ongoing habitat destruction (see ‘Habitat’) it’s been considered endangered at both the national and international level since 1990.


The ‘wet zone’ of southwestern Sri Lanka is an area receiving annual rainfall of 2000-3000 mm, much of which arrives during the South-West monsoons between March and August.

It’s a tropical environment with no significant dry spells or climatic changes, and air temperature is fairly constant throughout the year, ranging from 25 – 27 °C. Such conditions favour development of lowland tropical rainforest at altitudes below 1000 m AMSL.

In Sri Lanka these forests are found only in the wet zone and they’re inhabited by a significant proportion of the country’s endemic flora and fauna with the moist, warm climate and long period of geographic isolation leading to exceptional localised biodiversity.

The vast majority has been cleared for plantation agriculture, however, much of it when the country was under British colonial rule, though a significant portion was also removed during the more-recent civil war, with more than 35% of the original cover lost between 1990 and 2005.

As of 2006 only 4.6% of the old forest was left with the remainder existing only in small, highly-fragmented patches, most covering areas less than 10 km², of which some are now officially-protected reserves.

Kottawa Forest is one of these and comprises just 15-20 hectares of wet, evergreen jungle, though the combined Kottawa-Kombala forest covers around 1600 ha. A number of minor, pristine streams containing clear or slightly-stained, shallow water traverse the reserve and these represent typical habitats of L. jonklaasi across its range.

Little sun is able to penetrate the forest floor so aquatic habitats are shaded and water temperature may be relatively cool, while conductivity and hardness are generally low and pH slightly acid.

Macrophytes are uncommon though there may be dense, marginal vegetation, sometimes overhanging the full width of the stream, the roots of which may penetrate the banks underwater.

Typical substrates are sandy but covered by a layer of leaf litter with fallen twigs and branches.

Sympatric fish species include Rasboroides vateriflorisPuntius bimaculatusP. kelumi,  P. titteya, Pethia nigrofasciataDawkinsia singhalaSchistura notostigmaMystus vittatusAplocheilus werneriChanna orientalisMalpulutta kretseri, and Mastacembelus armatus.

The Kottawa Forest habitat comprises a small blackwater stream and parameters were measured as follows between 1996 and 2004: water temperature 23.6-26 °C/74.5-78.8 °F, total hardness 0-1.5 °dGH, carbonate hardness 0-2 °dKH, conductivity 30-60 μS/cm−1, pH 5.9-8.1.

Maximum Standard Length

40 – 45 mm.

Aquarium SizeTop ↑

Base dimensions of 60 ∗ 30 cm or more are required.


Should not prove difficult to keep but must be provided with a soft, sandy substrate since some of its time will be spent completely buried, or with only eyes protruding. When coarser gravel is used it may become stressed or damage itself trying to dig, and feeding behaviour can be inhibited.

Other décor can include water-worn rocks and driftwood branches and tree roots arranged to form plenty of hiding places and shaded spots – add these prior to the substrate to prevent them being toppled by digging activity.

Lighting can be quite dim unless you intend to grow plants and a few handfuls of leaf litter would complement the natural effect.

As this species hails from sluggish waters high flow rates are best avoided although a degree of oxygenation is recommended.

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.

Water Conditions

Temperature20 – 25 °C

pH5.5 – 7.5

Hardness36 – 268 ppm


Probably a micropredator sifting mouthfuls of substrate through the gills from which insect larvae, small crustaceans and suchlike are extracted.

In the aquarium it should accept sinking dried foods but should also be offered regular meals of small live and frozen fare such as DaphniaArtemiabloodworm, etc.

Behaviour and CompatibilityTop ↑

Lepidocephalichthys spp. are peaceful both with one another and other fishes and there exist no reports of them harming tankmates though they may prey on eggs or fry.

They fare best in the presence of conspecifics and should ideally be kept in a group of 4 or more specimens.

L. furcatus should do well alongside fishes from similar environments that occupy the upper part of the water column such as TrichopodusTrichogasterTrichopsis or certain Danio species.

The presence of these should also make it less timid as the absence of fishes in the upper water column is often used as a signifier for approaching danger in nature.

Sand-dwelling loaches from the families Botiidae, Cobitidae and Nemacheilidae are also suitable but proper research is essential as some can be excessively territorial or otherwise aggressive.

Sexual Dimorphism

In mature males the pectoral fins are enlarged with fused, thickened innermost (7th and 8th) rays forming a structure known as the lamina circularis.

This generally varies in form depending on species and is present in some other cobitid genera though may be formed by different rays.

Adult females are typically heavier-bodied and a little larger then males.



NotesTop ↑

This species is not currently present in the aquarium trade and its conservation status perhaps precludes its suitability for the hobby.

It can be told apart from congeners by the following combination of characters as per Havird and Page (2010): caudal-fin truncate or rounded; scales on top of head absent; presence of three to six broad, regularly-spaced dark bars on caudal-fin; series of large, vertically elongated black spots on flanks, usually forming numerous irregular bars; dorsal-fin origin anterior to pelvic-fin origin; moderate to large size (maximum SL 45 mm).

The family Cobitidae, often referred to as ‘true’ loaches, is widely-distributed across most of Eurasia with the Indian subcontinent, Southeast Asia and China representing particular centres of species diversity.

Phylogenetic analyses by Tang et al. (2006), Šlechtová et al. (2007) and Šlechtová et al. (2008) revealed that the group constitutes a separate genetic lineage to the family Botiidae (the two were previously grouped together under Cobitidae as subfamilies Cobitinae and Botiinae).

In the most recent study Lepidocephalichthys was not found to be as closely-related to PangioLepidocephalus or Kottelatlimia as previously hypothesised though unfortunately the authors stop short of proposing an alternative theory.

All cobitids possess sharp, motile, sub-ocular spines which are normally concealed within a pouch of skin but erected when an individual is stressed, e.g. if removed from the water. Care is therefore necessary as these can become entangled in aquarium nets and with larger species even break human skin.


  1. Havird, J. C. and L. M. Page, 2010 - Copeia 2010(1): 137-159
    A revision of Lepidocephalichthys (Teleostei: Cobitidae) with descriptions of two new species from Thailand, Laos, Vietnam, and Myanmar.
  2. Kottelat, M., 2012 - Raffles Bulletin of Zoology Supplement 26: 1-199
    Conspectus cobitidum: an inventory of the loaches of the world (Teleostei: Cypriniformes: Cobitoidei).
  3. Ott, G. and H-J. Ende, 2004 - Zeitschrift für Fischkunde 7(1): 55-60
    A new locality record for Lepidocephalichthys jonklasi (Deraniyagala, 1956) (Teleostei: Cypriniformes, Cobitoidea, Cobitidae).
  4. 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).
  5. Šlechtová, V., J. Bohlen and A. Perdices, 2008 - Molecular Phylogenetics and Evolution 47(2): 812-831
    Molecular phylogeny of the freshwater fish family Cobitidae (Cypriniformes: Teleostei): delimitation of genera, mitochondrial introgression and evolution of sexual dimorphism.
  6. 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.

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