Lepidocephalichthys berdmorei (BLYTH, 1860)

SynonymsTop ↑

Acanthopis berdmorei Blyth, 1860; Lepidocephalus cataractus Fowler, 1939; Lepidocephalus guntea birmanicus Rendahl, 1948; ? Acanthophthalmus longipinnis Menon, 1992

Classification

Order: Cypriniformes Family: Cobitidae

Distribution

Thought to have been described from the Sittaung River basin, Bago Division, Myanmar but currently accepted to have a wide distribution including the following river systems and countries: Brahmaputra in Bangladesh; Manipur in Manipur state, north-eastern India; Irrawaddy, Sittaung and Salween in Myanmar; Chao Phraya and Mae Klong in Thailand; Mekong in Thailand and Laos.

The southern limit of its range is usually given as Trang Province, southern Thailand, and we’ve been unable to confirm its presence in China although some reports state that it’s been recorded there without providing specific details.

Populations are known to vary in colour pattern and adult size depending on locality.

Habitat

Unlike most members of the genus L. berdmorei shows a preference for headwaters and streams with clear, flowing water and substrates of rocks, pebbles, submerged tree roots, etc., although it’s sometimes collected from muddy or sandy zones in areas where leaf litter collects.

Many such habitats are likely to be seasonal in nature, e.g., swelling in volume, flowing more rapidly and increasing in turbidity during the annual monsoons which affect the majority of its range. 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. Some species have even been recorded to survive periods in moist sand or mud in the absence of water.

At the Hpa Lap Chaung (Hpa Lap stream) in Kachin State, Myanmar (part of the Ayeyarwady drainage) L. berdmorei was recorded in a stretch of clear, brownish water with a depth of 1-1.5 m.

This was heavily shaded by surrounding bamboo forest but contained no aquatic vegetation and the substrate was composed of small stones and mud.

Sympatric species included Rasbora rasbora, R. daniconius, ‘Puntius‘ thelys, Pethia didi, Devario strigillifer, Psilorhynchus breviminor, Parambassis roberti, Acanthocobitis botia, Badis kyar, Mystus pulcher plus unidentified members of Acanthocobitis, Xenentodon, Channa, Laubuca, and Oreichthys.

At the Powathain Chaung (Powathain stream) in Mon State, Myanmar during the dry season it was recorded in gently-flowing, clear, brownish water with a substrate of sand, some leaf litter and no aquatic plants. In images much of the stream’s bed is seen to be dessicated with large patches of exposed sand.

Sympatric species included Pethia stoliczkana, Rasbora daniconius, Acanthocobitis pictilis, Aplocheilus panchax, Badis ruber, Parambassis notatus, Xenentodon cancila, a form of Channa gachua plus unidentified species of Laubuca, Opsarius, Schistura, Lepidocephalichthys, Awaous, Glossogobius, and Parambassis.

Maximum Standard Length

Appears to depend on population to an extent. Maximum SL is normally given as 80-100 mm but we know of at least one instance where very large, 120 mm+, specimens have been traded.

Aquarium SizeTop ↑

Base dimensions of 75 ∗ 30 cm or more are required.

Maintenance

This species will do well in most well-maintained aquaria if plenty of hiding places are provided and should not harm softer-leaved plants.

However we highly recommend keeping it in a set-up designed to resemble a flowing stream with a substrate of variably-sized rocks, gravel and some water-worn boulders. Driftwood roots and branches arranged to form some shaded spots can also be added.

While the majority of aquatic plant species will fail to thrive in such surroundings hardy genera such as Microsorum, Bolbitis or Anubias can be grown attached to the décor and bright lighting will promote the growth of aufwuchs.

Unlike many fishes that hail from running waters it’s relatively tolerant to accumulation of organic wastes due to its specialised gastro-respiratory tract (see ‘Notes’).

Nevertheless it should not be added to a biologically immature aquaria, and if keeping alongside other species from such environments suitable equipment is necessary.

Install a powerful external filter or two to raise levels of dissolved oxygen and water movement , and perform weekly water changes of 30-50% tank volume.

Water Conditions

Temperature: 20 – 25 °C

pH: 6.0 – 8.0

Hardness: 36 – 215 ppm

Diet

Probably a micropredator feeding on insect larvae and suchlike in nature.

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. berdmorei makes an excellent addition to communities of suitably-sized stream-dwelling fishes. Good tankmates include small, peaceful cyprinids plus rheophilic loaches such as Gastromyzon, Pseudogastromyzon, Beaufortia or Sewellia and less territorial nemacheilids.

Stream-dwelling gobies from genera including Sicyopterus, Stiphodon, Rhinogobius and Lentipes can also make interesting additions to this kind of community.

Territorial or otherwise aggressive bottom-dwellers such as some nemacheilid loaches and cichlids are less suitable companions.

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 is present in most other cobitid genera though usually formed by the second ray.

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

Reproduction

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

NotesTop ↑

This is one of the most frequently-traded members of the genus and is an excellent choice for those new to keeping loaches.

It’s distinguishable from congeners by a combination of characters including: relatively large adult size (to at least 80 mm SL); rounded/truncate caudal fin; a scaleless patch on top of the head; relatively long anterior rostral barbels; irregularly-arranged, variably-sized blotches or spots on the flanks which never form stripes; usually a mid-lateral series of larger markings; a large black spot at the base of the branched caudal–fin rays; 3-6 dark bars on the caudal fin; lamina circularis in males composed of fused, thickened 7th and 8th pectoral fin rays forming a cylindrical structure.

The most similar-looking species is L. thermalis but it can be told apart by its much smaller adult size and the fact it has dorsally-orientated projections on the lamina circularis, missing in L. berdmorei.

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. 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.
3. 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.
4. Kottelat, M., 2012 - Raffles Bulletin of Zoology Supplement 26: 1-199
   Conspectus cobitidum: an inventory of the loaches of the world (Teleostei: Cypriniformes: Cobitoidei).
5. 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.
6. 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).
7. 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.
8. 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.
9. 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).
10. 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.
11. 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.