The diatom genus Gomphonema Ehrenberg in India: Checklist and description of three new species

Karthick, B and Kociolek, JP and Mahesh, MK and Ramachandra, TV (2011) The diatom genus Gomphonema Ehrenberg in India: Checklist and description of three new species. In: Nova Hedwigia, 93 (1-2). pp. 211-236.

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Abstract

We have compiled a checklist of Gomphonema Ehrenberg taxa reported previously from India. From forty-nine references, over 100 Gomphonema taxa have been reported, including 39 new taxon descriptions. In addition to these previous reports of Gomphonema taxa, we describe three new species. G. gandhii Karthick & Kociolek, sp. nov., G. difformum Karthick & Kociolek, sp. nov. and G. diminutum Karthick & Kociolek, sp. nov., all from hill streams of Western Ghats, India. Frustule morphology, as studied in light and scanning electron microscopy, is compared with that of other recently described Gomphonema species from Africa and Asia. All three Indian species have distinctly dilated proximal raphe ends, in addition to differentiated apical pore fields, septa, pseudosepta and a round external stigma! opening. Gomphonema gandhii is linear-lanceolate-clavate, has a wide axial area, and is 19-51 mu m long, 3-7 mu m broad. Gomphonema difformum is smaller than G. gandhii, and has a hyaline area around the headpole. Gomphonema diminuta is much smaller and narrower than the other two species. These species are distinct from their closest congeners by their sizes, shape and structure of the head pole, and striae densities. All these species were described from low nutrient, neutral, low ionic content streams of Western Ghats. As most other species described from tropical region these three species appear to be endemic to India. Moreover, within India they have hitherto only been found in Western Ghats, one of the twelve biodiversity hotspots of the World.

Item Type:	Journal Article
Publication:	Nova Hedwigia
Publisher:	E. Schweizerbart Science Publishers
Additional Information:	Copyright of this article belongs to E. Schweizerbart Science Publishers.
Keywords:	Bacillariophyceae;diatoms;Gomphonema;India;new species; taxonomy;valve ultrastructure
Department/Centre:	Division of Biological Sciences > Centre for Ecological Sciences
Date Deposited:	21 Sep 2011 05:18
Last Modified:	30 Jan 2012 09:50
URI:	http://eprints.iisc.ac.in/id/eprint/40554

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