Guwahati, Jul 19 (IANS): The lone African rhino at the Assam State Zoo here has died of old age, officials said on Wednesday.

African white rhino Mohan, who died on Tuesday night, was brought here for Rs 50,000 from the US in 1974.

"He died of old age around 11.30 p.m. last night (Tuesday). The male rhino was around 47 years old. The normal lifespan of rhinos is 45 to 50 years," Divisional Forest Officer of the Zoo, T. Mariswamy, told the media here.

According to sources in the Zoo, Mohan was one of the big crowd pullers in the Assam State Zoo.

White rhinos are not actually white but normally light grey to dark yellow in colour and have two horns -- the front one being longer and often attaining a length of 150 cm.

Experts say the name "white rhino" came from the African word "wijt" (sounding like "white") meaning wide, in a reference to its mouth.

White rhinos are among the largest living land animals, having a body length between 335 and 420 cm and a tail length of 50 to 70 cm.

Last Sunday, the zoo lost Swati, the country's oldest tigress in captivity. Swati, aged around 20, also died of old age. The 1998 born tigress was brought to Guwahati in 2005.