Alien Sea Slug Found In Chilika Lagoon In Odisha; Know More About This Atlantic Nudibranch Species

Bhubaneswar: A team of researchers, including three from Odisha, has recorded the presence of Atlantic nudibranch (Armina maculata), which is mostly confined to Mediterranean Sea and Atlantic coasts, in intertidal waters of Chilika lagoon.

“The unique species, which is alien to the region, was first spotted in the lagoon in March 2009 as dead and again in November 2014 in live and solitary form during the study of benthic macrofauna carried out between 2007 and 2020, covering six sampling point in four sectors – northern sector (fresh water region), central sector (brackish water region), southern sector (brackish water to marine region) and outer channel area (marine region),” researcher Debasish Mahapatro told Odisha Bytes.

The live Armina maculate, orange in colour with white pustules and foot, was collected from the outer channel area of the lagoon in the aftermath of Cyclone ‘Hudhud’ in October 2014.

While there are more than 50 species of Armina worldwide, only four species – Armina cinerea from Gulf of Kutch, Armina cygnea, Armina semperi from Andaman waters, Armina babai from Parangipettai coast in Tamil Nadu and also from Talsari and Bichitrapur mangroves in Odisha- have been documented in India. “The present study describes the first occurrence of Armina maculata in India, specifically in the outer channel area of Chilika lagoon, which is rich in molluscan diversity,” he said.

Mahapatro, a marine biologist who works with Odisha State Pollution Control Board, said that ballast water of ships may be responsible for introducing the alien species to non-native localities in Chilika lagoon, which boasts of an ideal condition for animals with food found in abundance. “Since it is is located in the mid-way between Visakhapatnam port of Andhra Pradesh and Paradip port of Odisha, the off-shore transect of Chilika is a busiest route with frequent ship movement,” he said.

However, its impact on the ecosystem is yet to be known. “Such alien species can pose a challenge to native species in terms of food and shelter by adapting, reproducing, spreading and, colonising the environment. This baseline information can help in further study about such alien species in the lagoon,” he said, while emphasising on regular research work in the region.