The Australian 50 cent denomination was first introduced as a silver coin with decimalisation on 14 February 1966, but was changed in 1969 to its current specifications: a large dodecagonal (12-sided) copper-nickel coin; apart from the usual design featuring the Australian Coat of Arms, the denomination is also extensively used to issue circulating commemorative coins with various reverses. It is one of the heaviest coins in regular circulation in the world.
Apart from circulating coins, the Royal Australian Mint has a range of Non-Circulating Legal Tender (NCLT) 50 cent coins issued for collectors, such as this one.
This coin is part of the Australian Antarctic Territory Series, and features the Humpback Whale.
The Australian Antarctic Territory (AAT) is a part of East Antarctica claimed by Australia as an external territory. The territory's history dates to a claim on Enderby Land made by the United Kingdom in 1841, which was subsequently expanded and eventually transferred to Australia in 1933. It is the largest territory of Antarctica claimed by any nation by area.
The humpback whale (Megaptera novaeangliae) is a species of baleen whale. It is a rorqual (a member of the family Balaenopteridae) and is the only species in the genus Megaptera. Adults range in length from 14-17 m and weigh up to 40 metric tons. The humpback has a distinctive body shape, with long pectoral fins and tubercles on its head. It is known for breaching and other distinctive surface behaviours, making it popular with whale watchers. Males produce a complex song typically lasting 4 to 33 minutes.
Found in oceans and seas around the world, humpback whales typically migrate up to 16,000 km each year. They feed in polar waters and migrate to tropical or subtropical waters to breed and give birth. Their diet consists mostly of krill and small fish, and they use bubbles to catch prey. They are promiscuous breeders, with both sexes having multiple partners. Orcas are the main natural predators of humpback whales. | 
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