Preliminary observation on the polymorphic forms in three species of the Genus Lepidocephalichthys Bleeker, 1863 of Northeast India
Keywords:Spined loaches, Lepidocephalichthys, Cobitidae, sub-orbital spine, polymorphism, Northeastern India.
The spined loaches under the genus Lepidocephalichthys Bleeker, 1863 under family Cobitidae are colourful freshwater fishes with both ornamental and food values and are characterized by the presence of a sub-orbital spine and pectoral rod formed by the fused last two pectoral-fin rays in males. Out of the 9 valid species of <i>Lepidocephalichthys</i> in the Northeateastern India, three species viz. <i>L. berdmorei, L. guntea, and L. irrorata</i> show great polymorphic features in terms of body morphology, meristic data and colour. In view of this, the current preliminary study has been taken up to contribute in solving the existing taxonomic ambiguities by documenting the various polymorphic forms observed in <i>Lepidocephalichthys</i> of the Northeastern India. Multiple comparisons through morphometry, meristic, anatomy and osteology of the specimens collected from different river systems from different parts of the Northeast India has been employed. The present study is based on the observation of 127 specimens of <i>Lepidocephalichthys</i> collected from various region of the Northeastern India and it has revealed the presence of polymorphism in three species viz. <i>Lepidocephalichthys berdmorei, L. guntea</i> and <i>L. irrorata. Lepidocephalichthys berdmorei</i> has been registered with 6 polymorphs, <i>L. guntea with 5 and L. irrorata</i> with 2. Further understanding on their molecular characterization is suggested to confirm the taxonomic status of these polymorphs.