Lepidocephalichthys hasselti (VALENCIENNES, 1846)

SynonymsTop ↑

Cobitis hasselti Valenciennes, in Cuvier & Valenciennes, 1846: Cobitis octocirrhus Kuhl & van Hasselt, in van Hasselt, 1823; Lepidocephalichthys nudus Machan, 1931: Lepidocephalus taeniatus Fowler, 1939; Acanthophthalmus unistriatus Roberts, 1993

Classification

Order: Cypriniformes Family: Cobitidae

Distribution

Described from the ‘Tjelankakam’ (Tjelankahan) River’ on the island of Java, Indonesia but since recorded from Myanmar (Salween River system), Thailand (Chao Phraya and Mekong plus the island of Koh Mahk), Laos (Mekong), Cambodia (Mekong), Vietnam (Dong Nai), Peninsular Malaysia, Sumatra, and Borneo.

Differences in colour and patterning depending on locality have led to problems with identification, and a handful of previously-valid species are now considered junior synonyms of L. hasselti.

Habitat

Most commonly found in shallow, slow-moving sections of streams or calm habitats such as swamps, oxbows, backwaters and paddy fields.

These are often heavily-vegetated or littered with submerged roots, branches and leaf litter, with substrates composed of soft mud or silt.

Water clarity and depth vary on a seasonal basis across much of its range, and at certain times of year it probably enters temporarily-flooded zones. Conversely during dry periods some habitats may become stagnant with blooms of macrophytic algae and resultant hypoxia (oxygen depletion).

Under such conditions members of this genus are able to use the intestine as a supplementary breathing organ and have been observed darting to the surface to gulp atmospheric air, and some have even been recorded to survive dry periods in moist sand or mud.

At one locality close to Ban Na Hwai, Chiang Mai Province, Thailand L. hasselti was collected from a shallow (<0.5 m) pool in a swampy zone between forest and rice fields.

The substrate was of mud, there was no aquatic vegetation and it was being used as drinking water by local animals, with the only effluent connected to a ‘small creek’. Other species found there were Physoschistura pseudobrunneana, Rasbora hobelmani and Systomus cf. orphoides.

In the Huai Nam Man river, Loei Province, Thailand, it was collected from a fairly narrow (4-6 m wide), shallow (~20 cm deep), flowing stretch with a substrate of pebbles alongside Nemacheilus pallidus, Homaloptera smithi, Schistura nicholsi, Rasbora borapetensis and Amblyceps mangois.

In a 2006 study L. hasselti was observed in the Duc My River, central Vietnam, in a gently sloping section around 25 m wide characterised by a series of rocky riffles, rapids and deeper pools with a mixed sand and gravel substrate.

Aquatic vegetation was almost non-existent although submerged parts of terrestrial plants were common. The water was crystal clear, around 1 m deep on average with a temperature of 86°F/30°C and pH 7.4.

Sympatric species included Akysis clavulus, Schistura namboensis, Annamia normani, ‘Puntius‘ rhombeus, Rasbora paviana, Trichopsis vittata, Parambassis siamensis, plus unidentified species of Rhinogobius and Stiphodon.

At the latter localitty L. hasselti displayed a clear preference for shallow bays with soft substrates and unlike all the other species was absent from sites with current.

Maximum Standard Length

45 – 60 mm.

Aquarium SizeTop ↑

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

Maintenance

Not 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

Temperature: 23 – 26 °C

pH: 5.5 – 7.5

Hardness: 36 – 179 ppm

Diet

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

In the aquarium it will accept sinking dried foods but should also be offered regular meals of small live and frozen fare such as Daphnia, Artemia, bloodworm, 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. hasselti should do well alongside fishes from similar environments that occupy the upper part of the water column such as Trichopodus, Trichogaster, Trichopsis 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.

A community based around fishes occurring in similar habitats from Thailand, for example, could include species such as Boraras maculatus, B. uropthalmoides, Danio albolineatus, D. kerri, D. roseus, Eirmotus octozona, Pangio anguillaris, P. kuhlii, P. myersi, ‘Puntius‘ johorensis, ‘P.‘ partipentazona, Pethia stoliczkana, P. ticto, Rasbora borapetensis, R. einthovenii, R. rubrodorsalis, Trichopsis pumila, T. vittata, Trigonostigma espei, T. hengeli, T. heteromorpha, and Ambastaia sidthimunki.

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 formed by different rays though formed by different rays.

Adult females are typically heavier-bodied, a little larger then males and have spotted patterning on the flanks as opposed to a dark stripe.

Reproduction

Presumably a seasonal spawner in nature but hasn’t been bred in captivity as far as we know.

NotesTop ↑

L. hasselti is widely-distributed and thus relatively common in the aquarium hobby.

It’s distinguishable from congeners by a combination of characters including: truncate caudal-fin; a scaleless patch on top of the head; reticulated patterning in the caudal-fin; irregular spotted patterning on flanks, most often forming a row of adjacent dark blotches or solid stripe with a light, unpigmented stripe above; relatively narrow caudal peduncle; usually a small, black spot at the base of branched caudal-fin rays 3-4, replaced by a dark patch if not present; lamina circularis in males composed of fused, thickened 7th and 8th pectoral-fin rays forming a small, rounded, dorsally-orientated flange-like structure.

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 Pangio, Lepidocephalus 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.

References

1. Arunkumar, L., 2000 - Journal of Fish Biology 57(5): 1093-1104
   Loaches of the genus Lepidocephalicthys (Lepidocephalichthys) from Manipur, with description of a new species.
2. Freyhof, J., D. V. Serov and T. N. Nguyen, 2000 - Bonner Zoologische Beiträge 49(1-4): 93-99
   A preliminary checklist of the freshwater fishes of the River Dong Nai, South Vietnam.
3. 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.
4. Herder, F. and J. Freyhof, 2006 - Journal of Fish Biology 69(2): 571-589
   Resource partitioning in a tropical stream fish assemblage.
5. Kottelat, M., 1990 - Verlag Dr. Friedrich Pfeil, München, Germany: 1-262
   Indochinese nemacheilines. A revision of nemacheiline loaches (Pisces: Cypriniformes) of Thailand, Burma, Laos, Cambodia and southern Viet Nam.
6. Kottelat, M., 2001 - WHT Publications Ltd., Colombo 5, Sri Lanka: 1-198
   Fishes of Laos.
7. Kottelat, M., 2012 - Raffles Bulletin of Zoology Supplement 26: 1-199
   Conspectus cobitidum: an inventory of the loaches of the world (Teleostei: Cypriniformes: Cobitoidei).
8. 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.
9. Kottelat, M. and K. K. P. Lim, 1992 - Raffles Bulletin of Zoology 40(2): 201-220
   A synopsis of the Malayan species of Lepidocephalichthys, with descriptions of two new species (Teleostei: Cobitidae).
10. Mittal, S., P. Mittal and A.K. Mittal, 2004 - Belgian Journal of Zoology 134(1): 9-15
    Operculum of peppered loach, Lepidocephalichthys guntea (Hamilton, 1822) (Cobitidae, Cypriniformes): a scanning electron microscopic and histochemical investigation.
11. Moitra, A., O. N. Singh and J. S. D. Munshi, 1989 - Japanese Journal of Icthyology 36(2): 227-231
    Microanatomy and cytochemistry of the gastro-respiratory tract of an air-breathing cobitidid fish, Lepidocephalichthys guntea.
12. Rainboth, W. J., 1996 - FAO, Rome: 1-265
    Fishes of the Cambodian Mekong. FAO Species Identification Field Guide for Fishery Purposes.
13. 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).
14. 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.
15. 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.