In a first, scientists document predatory free-living marine nematode species

Kolkata: Scientists from the Zoological Survey of India (ZSI), Marine Aquarium and Regional Centre (MARC), Digha have for the first time documented a predatory free-living marine nematode species from the Indian waters. The new nematode species Parasphaerolaimus bengalensis sp. nov., has been discovered from sediment samples collected on August 14, 2024, at a depth of approximately 10 cm using a hand corer from the intertidal zone of the meeting point of the river Champa with the Bay of Bengal.

The newly-identified species Parasphaerolaimus bengalensis sp. nov. belongs to the order Monhysterida and exhibits distinct morphological characteristics, including a thick, slender body with a large buccal cavity, presence of lateral alae on striated cuticle, short cephalic and subcephalic setae, numerous longitudinal rows of cervical setae and spicules with round-shaped distal ends, which differ from other species of the same genus.

The discovery has been made by a research team led by S Balakrishnan, Scientist-E, along with Chaiti Manna, ZSI, MARC, Digha, and Kapuli Gani Mohamed Thameemul Ansari of C. Abdul Hakeem College (Autonomous), affiliated to Thiruvalluvar University, Tamil Nadu.

Nematodes are generally known for their parasitic forms, but their diversity is large in free-living forms found in almost all types of habitats. Free-living nematodes play a major role in the marine food web and it is an important ecological indicator species, sensitive to pollutants and their population structure can reflect the health of the environment.

The significant finding has been published online in Thalassas: An International Journal of Marine Sciences. It highlights that the rich biodiversity of the area surrounded by recent mangrove wetlands is characterised by nutrient-rich habitats that will promote benthic communities and productivity.

“This discovery sheds light on the vast and largely underexplored diversity of marine life and adds to our growing understanding of marine meiofaunal diversity. Although free-living marine nematodes are among the most numerically dominant animals in marine sediments, new species are still being documented in many parts of the world’s oceans,” Balakrishnan said.

The research team wants to conduct further studies to understand the marine meiofaunal community and plans to explore nearby areas for other undiscovered organisms.