Order: Cetacea.

Family: Physeteridae.

Size: Length- male 49 to 62 ft (15-19 m); female 26 to 39 ft (8-12 m).

Weight: Male 45 to 57 tonnes; female 15 to 24 tonnes.

Key Features: Largest of the toothed whale has a distinct and unusual shape; head huge almost one-fourth to one-third of its body length; snout blunted and squarish projecting up to 1.5 m beyond the tip of the lower jaw; lower jaw narrow, weak and disproportionately small; back has hump and no fin; flippers short, tail large and deeply notched; colour may be dark brown, grey or black with belly and front of head light grey; 18 to 25 sturdy conical teeth present on the lower jaw which fits into sockets in the upper jaw; blowhole located on the front of head on the left.

Voice: Clicks used for communication and echolocation.

Breeding: Single calf born every 4 to 6 yrs after gestation period of 14 to 16 months. Weaned at 1 to 3 yrs, sometimes longer; females sexually mature at 7 to 13 yrs, males at 18 to 21 yrs. May live at least 60 to 70 yrs.

Diet: Mostly squid, cuttlefish, octopus and fish.

Habitat: Found in deep water of temperate and tropical regions and have a preference for volcanic islands.

Habits: Most females will form lasting bonds with other females of their family, and on average 12 females and their young will form a family unit. As males get older and larger, they begin to migrate to higher latitudes (toward the poles) and slowly bachelor schools become smaller, until the largest males end up alone. Their skin is up to 35 cm thick which is the thickest skin of any existing animals is. Apart from the theory that Sperm Whales may kill or stun prey with sound, there is another hypothesis that they may lure their food into their mouths using luminescent organisms.

Conservation Status: Species listed as ‘Vulnerable’ globally on IUCN red list with population range in between 200000 to 1.5 million.

Distribution in Gujarat: There are many cases of live Sperm Whale stranding on the Indian coast wherein one species of length 4.27 m stranded at the Jakhau coast in Kachchh district in July 1998.

 

 

 

 

 

References:

• Sathasivam, K. (2004). Marine Mammals of India. Universities Press (India) private limited. Hyderabad. Pp: 40

• Marine Mammals Facts Courtesy: Animal Fact Files- Mammals. The Brown Reference Group Plc.