Biodiversity of jellyfish in the Indian coastal Ecosystem: Structural diversity, functional ecology, and venom...

Jellyfish are the most influential taxa in the marine ecosystem, establishing a prominent effect on the food web, and economic and fishing aspects of a particular environment. These gelatinous zooplanktons tend to have both positive and negative impacts on a specific ecosystem. Jellyfish swarming, blooms, and the invasion of non-indigenous species instigate economic and environmental implications. Thus, the study of the Jellyfish fauna along the coasts of India is essential in prospecting the dynamics of species diversity, climate change and pollution status. A crucial aspect of jellyfish research is the Nematocysts, a specialized stinging cell known for its potent venom, and they are a vital source of marine bioactive compounds. In our present study, we present an overview of the diversity of Jellyfish species along the Indian coasts. Based on a comprehensive literature survey of various reports of Jellyfish identification in the Indian region from 1930 to 2023, 51 species of jellyfish have been recorded in various coastal areas of Tamil Nadu, Andhra Pradesh, the Gulf of Mannar, Goa, Kerala and Gujarat. Additionally, our study highlights the variation in nematocyst morphology across different species, including techniques for nematocyst isolation and methods for venom extraction. The review emphasizes the structural differences seen in individuals of species found in India and their significance in the toxin profile of the organism. Recent studies suggest that environmental variables such as sea surface temperature, salinity, and eutrophication influence both species distribution and structural variation in jellyfish. This structural variation and ecological influence across species provide insights into species identification, survival strategies and evolution of jellyfish. Besides increasing interest in Cnidarian toxins, the toxin profiles of Indian jellyfish species remain underexplored for biomedical applications. By integrating various aspects of jellyfish diversity, this review finds critical gaps in biodiversity and toxin biology of jellyfish in the Indian subcontinent.