Researchers have discovered a new species of gomphonemoid diatom found in a freshwater river of the Eastern Ghats. This species has several interesting features that distinguish it from other members of the gomphonemoid group in terms of valve symmetry and some other valve features. It has been named Indiconema to acknowledge its restricted distribution in the country. This research underlines the importance of diatoms in shaping the biodiversity of India's diverse landscapes.
Diatoms are microscopic algae that play a vital role in our daily lives by producing 25 percent of global oxygen, or about every fourth breath of oxygen we take. They serve as the base of the aquatic food chain. Due to their sensitivity to any water chemistry changes, they are excellent indicators of aquatic health.
Diatoms are the earliest recorded microorganisms in India. Ehrenberg's first report on this appeared in his major publication Microgeology in 1845. Since then, diatoms have been recorded from freshwater and marine environments in numerous studies in India. According to a rough estimate, there are about 6,500 diatom taxa, of which 30 percent are endemic (restricted to a particular region) to India, which is a testimony to India's unique biodiversity. In addition, the diverse biogeographical regions suit different species with habitat diversity ranging from freshwater to marine, sea level to high mountains and alkaline lakes to acidic swamps. Peninsular India consists of the Eastern and Western Ghats. These have distinct physical, soil and climatic gradients that provide a wide range of habitats with unique geographical conditions and also favour a unique set of diatoms.
Scientists at Agharkar Research Institute (ARI), an autonomous institute of the Department of Science and Technology, Pune, discovered Indiconema. This Indiconema has a pore region at both the head and foot poles instead of having a pore region only at the foot pole.
The increasing monsoon has structured the rainforest biome in the Indian peninsula and created associated varying moisture levels, which have a direct role in shaping the diatom flora.
The research, published in the journal Phycologia, reports that one species of Indiconema is found from the Eastern Ghats and the other from the Western Ghats. A similar pattern of sharing of endemic elements between the two mountain systems has been observed for other endemic-rich groups, such as reptiles.
Further, based on the morphological features of this group, the researchers have suggested that Indiconema is a sibling of Afrocymbella, a species endemic to East Africa. Initial studies found similarities between Gomphonema species from India and East Africa and Madagascar, which is also recognised by the current study group. The erstwhile SERB, now ANRF, has said that this discovery is of great significance for the ongoing research to unravel the mysteries of diatom biogeography and their role in shaping the biodiversity of India's diverse landscapes.
Publication link: https://doi.org/10.1080/00318884.2023.2268381