Investigating agent Akhilesh Pratap Singh told CNN that the dolphin carcass was found on the Sharda Canal embankment in Pratapgarh district on December 31st.
Three individuals allegedly seen in the video were arrested on Thursday, police said. Nine people, who are also seen in the video, continue to flee, according to Singh.
The video shows a group of men with sticks and an ax killing the dolphin. Some laughed when the dolphin’s near-life body was dragged by its fin into the shallow waters.
Forestry officer Varun Singh, who was part of the initial investigation, told CNN that the dolphin had been an adult dolphin from the Ganges River.
The Ganges River dolphin was “once present in tens of thousands of numbers,” but has now “abysmally dwindled” to a population of less than 1,800 in the last century, according to India’s World Wildlife Fund (WWF).
The rare freshwater dolphin is essentially blind and is known locally as “susu,” a reference to the noise it makes when it breathes, according to the WWF.
When hunting, the dolphin emits ultrasonic sounds that bounce off fish and other prey that allow them to visualize an image in their mind.
According to the WWF, female dolphins in the Ganges River give birth to a single calf once every two or three years.