In southern India, two different species of mussels green (Perna viridis) and brown(Perna indica) are found abundantly. The brown mussel was named as a new species,P. indica , in 1976.
The specific status of the brown mussel, P. indica , in southern India and northern Sri Lanka has long been questioned, reported the authors of the study published in an international journal Biological Invasions .
“Its limited geographical distribution within the extensive range of the Asian green mussel, P. viridis , and its morphometric similarity to the African brown mussel, P. perna, have led several authorities to suggest that P. indica is not a distinct species but is in fact introduced P. perna ,” stated the study.
Jonathan Gardner, the lead author of the study and Professor of Marine Biology, School of Biological Sciences, Victoria University of Wellington, New Zealand, told Muscat Dailythat his team was able to use a gene, called cytochrome oxidase one, to show that the brown mussel in India is, in fact, the Omani brown mussel. “This is possible because the Omani brown mussel is a distinct lineage of brown mussels only found in Oman, so by matching the gene sequences of the Indian and the Omani brown mussels it was possible for us to say that the Indian brown mussel must have come from Oman and nowhere else,” he said, adding that it has now been confirmed that P. indica is in fact an introduced population of P. perna .
Gardner added that the Omani brown mussel was introduced into India more than 100 years ago.
He noted that there is a strong evidence of a very old (at least 2000 years) ship-based trade route between Oman and Colachel, which is at the geographic centre of the present-day distribution of P. perna in southern India. “The most likely mode of introduction of the brown mussel was via a ship travelling from Oman to the Indian port of Colachel. The mussels would have been attached to the ship’s hull and may have fallen off once in port in India or may have spawned once in port in India.”
He further said that his group is now working on other related research. “We are interested to see if the introduced brown mussel and the native green mussel interbreed in southern India. We are also interested to see if the introduced brown mussel is still expanding its range in southern India.”
P. perna forms high density populations that have long been fished by local coastal communities and recently the fishery for P. perna has expanded to markets beyond the coastal area and is an important source of protein and revenue for the local community, reported the study.