Lepidocephalichthys zeppelini HAVIRD & TANGJITJAROEN, 2010

Etymology

zeppelini: named for the rock band Led Zeppelin because the diagnostic double lamina circularis of this species reminded the authors of the Gibson EDS-1275 double-neck guitar used by Jimmy Page.

Classification

Order: Cypriniformes Family: Cobitidae

Distribution

Known from the middle and lower Mekong river system in Thailand and Vietnam, plus the Chao Phraya drainage in central Thailand.

Type locality is ‘Mun River, tributary of Mekong River, Ubon Rajathanee University campus, 15°08’03.18″N, 104°55’27.78″E, Ubon Ratchathani, Thailand’.

Habitat

The type locality consisted of remnant ephemeral pools in otherwise dry agricultural land, and many adults were collected from such habitats.

Other species present included the congener L. hasselti plus members of  Anabas, ‘Puntius‘, Rasbora, Channa, and Hampala.

Small streams, marshes and flooded rice paddies were also sampled but only one juvenile was collected from a sandy stream.

The majority of congeners tend to inhabit 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.

Maximum Standard Length

The largest specimen known measured 25.8 mm.

Aquarium SizeTop ↑

Base dimensions of 45 ∗ 30 cm or more are recommended.

Maintenance

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

Temperature: 20 – 26 °C

pH: 6.0 – 7.5

Hardness: 36 – 215 ppm

Diet

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 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. irrorata 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.

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, which in this case forms a large, dorsally projecting, rounded rectangular flange with approximately 25 fine serrations plus a smaller, ventrally rounded flange.

Males also have larger pectoral and pelvic fins plus a significantly smaller adult size with an average SL of 18.1 mm and maximum 21.7 mm vs. an average of 19.9 mm and maximum 25.8 mm SL in females.

There are also differences in colour pattern, with adult females tending to possess spots on the flanks and males a narrow, dark lateral stripe.

Reproduction

Unrecorded.

NotesTop ↑

This species is not traded often but may occasionally be exported as bycatch among shipments of other species.

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. Havird, J. C., L. M. Page, W. Tangjitjaroen, C. Vidthayanon, C. Grudpan and S. Udduang, 2010 - Zootaxa 2557: 1-18
   A new species of Lepidocephalichthys (Teleostei: Cobitidae) with distinctive sexual dimorphism and comments on relationships in southern lineages of Cobitidae.
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., 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. 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).
6. 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.
7. 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.