ZSI scientists record a stranded skeletal system of short-finned pilot whale from Andamans – Times of India

During a recent survey, by the Zoological Survey of India (ZSI) scientists, more particularly, those belonging to the Andaman and Nicobar Regional Centre, Port Blair recorded, a stranded skeletal system (incomplete) of the Short-finned Pilot Whale (Globicephalamacrorhynchus Gray, 1846) from South Reef Island of North and Middle Andaman region, stated Dr Dhriti Banerjee, Director, ZSI today. The survey was led by Dr Tamal Mondal, Scientist-C, Andaman and Nicobar Regional Centre.

Dr Banerjee informed that nine reports were made so far on the stranding incidents of Short-finned Pilot whales in Indian waters including five incidents as mass stranding reports (20 individuals from Calcutta in 1850; one large hard from Calcutta in 1852; 147 individuals from Manapad of Tamil Nadu in 1973; 40 individuals from Elizabeth of Andaman and Nicobar Islands in 2012; 81 individuals from Manapad of Tamil Nadu in 2016), one report with two individuals (from Pudukuppam of Tamil Nadu in 1986), and four reports are with a single individual (from Serampur of West Bengal in 1852 & 1859; Calcutta of West Bengal in 1859). Sighting of this species is also reported from Maharashtra, Malabar Coast, and Lakshadweep.

This time, the stranded skeletal system of the Short-finned Pilot Whale containing 1 skull, 1 lower mandible, 3 ribs, 37 vertebrae, 1 scapula, 2 humeri, 2 radii, and 2 ulnae was reported from the sandy coastal areas at South Reef Island of Andaman and Nicobar Islands as first stranding report of a solitary individual of Short-finned Pilot Whale in Andaman and Nicobar Islands, stated Dr Banerjee.
As Dr Tamal Mondal puts it, most of the parts of the skeletal systems were excavated out from sandy coastal areas and marks of the terrific level of weathering due to high oceanic wave actions, variation in temperature ranges along with natural calamities like a cyclone was observed from those parts.

Two species of Pilot Whales as Short-finned Pilot Whale (Globicephalamacrorhynchus Gray, 1846) and Long-finned Pilot Whale (G. melas (Traill, 1809)) are known across the world. Short-finned Pilot Whales are very common in tropical and temperate regions. The black or dark grey body colour with a bulbous head, absence of beak, and presence of low and falcate dorsal fin are the common diagnostic features of the Short-finned Pilot Whale.

According to Dr Banerjee, the Short-finned Pilot Whales are one of the best-known social animals and perform their duties and lifestyle like movement, and predation in a group which can result in mass stranding. The mass stranding of this species may be seen due to various reasons such as alteration in geo-spatial and geo-magnetic, earthquake or related seismic alterations, climatic changes, tidal amplitudes, bio sonar dysfunction, sonic waves due to the military exercise, and various anthropogenic means, etc. whereas the death of one or more than one individual in the entire pod can be seen due to some specific anthropogenic activities host nets, fishing gears or accidents by boats, or direct physical injuries or due to disease.