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E-ISSN: 2347-5129, P-ISSN: 2394-0506

International Journal of Fisheries and Aquatic Studies

2016, Vol. 4, Issue 3, Part A

Biometric variations among populations of Carnatic ricefish (Oryzias carnaticus, Jerdon, 1849), a native larvivorous fish of South India


Author(s): Shalu Thomas, Lijo John, Alex Eapen

Abstract: The possibility of any biometric variations in Oryzias (ricefish) populations present in three geographically isolated drainages around the city of Chennai, India were studied. Though biometric characters were insufficient to differentiate the three populations as distinct species, the dorsal and anal fin ray counts had shown considerable variation from the baseline information reported earlier besides, certain scale counts were significantly different among as well as between the populations. Branched pelvic fin ray counts (6-7) of Sriperumbudur population was different from the baseline information (6). The anal fin rays of saline inhabitant population were higher compared to those in freshwater. Furthermore, as most of the baseline meristic variables overlap from one species to another, identification of Oryzias carnaticus and Oryzias dancena need not be solely based on the meristic characters. The application of biometrics has limitations in identifying this species and molecular techniques may resolve the taxonomic ambiguity of Oryzias species in the Indian subcontinent.

Related Graphics: Click here for more related graphics:

Scatter diagram based on PCA of significant meristic variables among populations of O. carnaticus (Perungalathur- Blue squares; Pulicat- Violet Circles; Sriperumbudur- Blue Stars; Component 1- 32.47%; Component 2- 21.82%).
Fig. 1: Scatter diagram based on PCA of significant meristic variables among populations of O. carnaticus (Perungalathur- Blue squares; Pulicat- Violet Circles; Sriperumbudur- Blue Stars; Component 1- 32.47%; Component 2- 21.82%).
Scatter diagram based on PCA of significant morphometric variables among populations of O. carnaticus (Perungalathur- Blue squares; Pulicat- Violet Circles; Sriperumbudur- Blue Stars; Component 1- 30.04%; Component 2- 19.32%).
Fig. 2: Scatter diagram based on PCA of significant morphometric variables among populations of O. carnaticus (Perungalathur- Blue squares; Pulicat- Violet Circles; Sriperumbudur- Blue Stars; Component 1- 30.04%; Component 2- 19.32%).


Pages: 22-26  |  903 Views  60 Downloads

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How to cite this article:
Shalu Thomas, Lijo John, Alex Eapen. Biometric variations among populations of Carnatic ricefish (Oryzias carnaticus, Jerdon, 1849), a native larvivorous fish of South India. Int J Fish Aquat Stud 2016;4(3):22-26.
International Journal of Fisheries and Aquatic Studies