The giant Australian
cuttlefish (Sepia apama) is the
world’s largest cuttlefish species, growing up to 50 centimetres in length. They
have 10 appendages – 8 short arms and 2 larger tentacles.
The cephalopod is
native to the southern coast of Australia, from Brisbane to Western Australia.
It is commonly found on rocky reefs and in seagrass. Their lifespan is 2-3
years. They are known for changing colour rapidly, due to their chromatophores.
They are carnivorous (meat eaters), preying on crabs, small lobsters, and fish.
Their predators are fur seals, sea lions, albatross, and bottlenose dolphins. Bottlenose
dolphins can remove the ink and cuttlebone from the cuttlefish before eating
them.
Their breeding ground
in Australia is the upper Spencer Gulf in South Australia near Whyalla during
May and August each year. The spawing period is an extraordinary event
attracting marine biologists and tourists from around the world. Their mating
ritual is elaborate, using multi-coloured strobing effects and psychedelic
skin patterns to attract mates. They literally light up!!
Cuttlefish are mostly used for their ‘bones’ – which are actually soft,
calcareous material – for pet birds to sharpen and clean their beaks.
The International
Union for the Conservation of Nature (IUCN) listed the Sepia apama as ‘near threatened’ in 2012. In 2011 the number
of cuttlefish in Spencer Gulf declined drastically for an unexplained reason.
Instead of hundreds of thousands of cuttlefish, the count dropped to about
13,500 in 2013. They were facing extinction as early as 2016.
The South Australian
government established a Cuttlefish Working Group in 2013 to address the
problem and to establish a research program. Now numbers are increasing and
the Sepia apama may be making a
spectacular comeback. Scientist will continue to monitor their numbers and
advocate for extended research programs.
The South Australian
Research and Development Institute (SARDI) recorded the cuttlefish population near
Whyalla at more than 130,000 this year – a vast improvement on the previous two years.
The Whyalla Cuttlefish Citizen Scientist Group and Conservation Council SA
say cuttlefish are the rock stars of South Australia’s marine environment.
MARTINA NICOLLS is an international
aid and development consultant, and the author of:- The Shortness of
Life: A Mongolian Lament (2015), Liberia’s Deadest Ends (2012), Bardot’s Comet
(2011), Kashmir on a Knife-Edge (2010) and The Sudan Curse (2009).
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