Researchers have identified a dwarf sperm whale – a distinct species of the mammal that looks like a shark and is slightly smaller than most dolphins – for the first time in the Bay of Bengal in Kuakata, Patuakhali.
When local fishermen found the whale stranded near the beach alive, they tried to release it into the sea several times. Unfortunately, it repeatedly floated back to the shore due to tides and died two hours later.
After a photo of the whale was spread on social media, it was identified as Kogia breviceps, the scientific name of the species.
Sagarika Smriti, an associate researcher of WorldFish Bangladesh, told The Business Standard on 22 May, that the whale was found in the mouth of the River Andharmanik near Lemburchar in Kalapara upazila of Patuakhali. The whale was pregnant and buried with two babies in her womb.
It was initially thought to be a dolphin but after it was exhumed the next day, it was identified to be a dwarf sperm whale, a species that lives mainly in the deep sea and has never been seen before in the Bay of Bengal, she added.
Nadeem Parvez, a member of the Bangladesh Wildlife Conservation Society (WCS), said the members of the Kuakata Dolphin Preservation Society shared photos of the whale on social media. With its square head, a white stripe on the side of the head like artificial gills, and a protruding nose, the whale looks almost like a shark.
Using these traits, this mammal fools predatory whales and large sharks by pretending to be sharks. Another feature of this species of whales is they have a small sac filled with reddish-brown liquid attached to their intestines. They throw liquids into the water from the sac in the presence of predators to hide themselves, similar to what an octopus does, he added.
Nadeem Parvez further said the dwarf sperm whale is one of more than 90 species of cetaceans discovered in the world so far. Cetaceans spend their entire life in water and breathe air. But, these whales do not chew the prey but swallow them completely.
"Surprisingly, the whale had two babies in her womb, which is very rare among cetaceans as they usually give birth to one baby at a time," he said.
Md Rasel Mia, a member of WCS, said, "We know very little about this deep-sea creature as this species was never seen in the seas of Bangladesh in more than one decade of research of the WCS. The number of this species in the sea maybe more."