Scientists have confirmed that ‘brown mussel’ found along the southern coast of India was introduced from Oman region over a 100 years ago.
Research by scientists from Suganthi Devadason Marine Research Institute (SDMRI), Thoothukudi, Rajiv Gandhi Centre for Biotechnology in Thiruvananthapuram and Victoria University of Wellington in New Zealand confirmed that the brown mussel distributed in Southern India belongs to “Perna perna” species.
The research results were published in an international journal “Biological invasions”.
The results revealed that “combined evidence indicates that Perna indica Kuriakose and Nair 1976 is Perna perna (Linnaeus, 1758) from Oman region introduced into southern India more than 100 years ago”.
Speaking to The Hindu here on Tuesday, J.K. Patterson Edward, Director, SDMRI, Thoothukudi, said globally only three valid mussel species existed and they were green-lipped mussel, Perna canaliculus, brown mussel, ‘Perna perna’, and green mussel, ‘Perna viridis’.
In southern India, two different species of mussels (green and brown mussels) had been reported. Green mussel was Perna viridis, whereas the brown mussel was named as a “new species, ‘Perna indica’, in 1976”. However, the taxonomic status of P. indica had long been questioned.
Analysis of DNA sequence for nuclear Internal Transcribed Spacer (ITS) and mitochondrial Cytochrome c Oxidase Subunit I (COI) sequence data from newly collected mussels from southern India examined in the context of data from Genbank for mussels of the genus Perna revealed that P. indica was indeed P. perna from Oman region.
Reports of ecological interactions between the native P. viridis and the introduced P. perna revealed that P. perna grew to a larger size than P. viridis and out-competed the native mussel.
“The brown mussel, P. perna, forms high-density populations that have long been fished by local coastal communities and recently fishery for P. perna has expanded to markets beyond the coastal area,” Dr. Edward said.
Eradication of the introduced P. perna was not feasible and not desirable as it tended to be source of protein and revenue for the local community. “P. perna fishing at 10 villages between Kanniyakumari and Enayam contributes annually about 400 tonnes and its cost is about Rs. 30 per kg. Over 1,200 fishermen are involved in sustainable harvesting only from November to April by traditional skin diving method,” he said.
The trade through Colachel port in olden times could be the reason for invasion of P. perna from Oman via hull fouling and ballast water, he added.
Trade through Colachel port in olden times could be the reason for invasion of this species from Oman via hull fouling
