A new, large species of Gomphonema Ehrenberg from ancient Lake Matano, Indonesia

Abstract

A large species of the diatom genus Gomphonema Ehrenberg, G. matanensis sp. nov., is described as new to science from ancient Lake Matano, Indonesia. Light and scanning electron microscopic observations of the valve morphology of this species are presented. The morphology of this species is similar to other large species that have ovoid areolar openings without external flaps or occlusions, such as G. gomphopleuroides Amossé ex Kociolek, Glushchenko & Kulikovskiy and members of the G. kaznakowi species complex, both known from Southeast Asia. This species has the special features of bi- and triradiate siliceous growths at the valve mantle junction, continuing onto the mantle. Though an analysis of the phylogenetic relationships of the diatom genus Gomphonema is currently wanting, it would appear that gigantism occurred several times within the genus.

Keywords:

• Bacillariophyceae
• diatoms
• Gomphonema
• ancient lakes
• Indonesia
• morphology
• systematics

ORCID

Dmitry Kapustin http://orcid.org/0000-0003-3256-7776

Additional information

Funding

This publication is based on research carried out with financial support by Russian Foundation for Basic Research [16-34-60099 mol_a_dk and 17-04-00042-a] and MK was partly supported by Russian Government Program of Competitive Growth of Kazan Federal University.