New marine amphipod species found in Chillika Lake, Odisha

Researchers at Berhampur University, Odisha have discovered a new species of marine amphipod — a shrimp-like crustacea of genus Demaorchestia— in the state’s Chilika lake on the east coast of India.

The new species was named Demaorchestia alanensis after global expert professor Alan Myers of University College Cork, Ireland, who has made a significant contribution to global marine amphipod studies, said Shesdev Patro, assistant professor, Department of Marine Science, Berhampur University and one of the three researchers who discovered the new species.

The present contribution has added one more species to the genus Demaorchestia, raising the global species number in the group to six, he said.

The characteristics of the newly discovered crustacean were described in an article, A new species of amphipod of the genus Demaorchestia (Senticaudata, Talitridae) from Chilika Lagoon, east coast India, in the online edition of journal Zootaxa, on December 11, 2023. 

“We collected at least eight specimens of the species from Barkul beach in Ganjam district, Odisha on the shore of the Chilika lake in January 2022 by handpicking. After a thorough survey and testing in the university laboratory, we have reached the conclusion that it is a new species and different than other fives found globally,” said Gitanjali Bhoi, research scholar and co-author of the article.

The specimens were deposited in the Zoological Survey of India’s Estuarine Biology Regional Centre, Gopalpur-on-Sea, Odisha for further research, said Lipika Tarafdar, another researcher and the third co-author.

The study has revealed that the new species is white in colour and less than 15 millimetres in length. It has 13 pairs of legs. While three pairs are used for swimming in the water, eight pairs are used for walking on land. The other two pairs are used for capturing prey and feeding, Patro said. 

The species can be distinguished from the other members of the genus by two to three strong, hair-like structures or setae on the anterior margin of the propodus of the gnathopod. It belongs to the subfamily Platorchestiinae found along the Indian coast, he added. 

Amphipods are a significant group in the marine ecosystem and play a vital role in the marine food chain. They also serve as indicators for studying the impact of climate change and health of coastal ecosystems, he said. Further research will delve deeper into understanding the specific ecological roles of amphipods in coastal and marine environments, Patro said.

The family Talitridae was considered one of the oldest groups of amphipods,and it was believed to have been on the planet since the Jurassic age. It is divided into four subfamilies: Talitrinae, Floresorchestiinae, Pseudorchestoideinae and Platorchestiinae. In the Indian context, the family Talitridae is represented by only Talitrinae and Floresorchestiinae, he said.

Earlier, Patro and Bhoi discovered another two marine amphipods Quadrivisio Chilikensis from the seaweeds near Nalaban, the bird sanctuary area of the lagoon and Talorchestia buensis from the West Bengal coastal area.