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Help needed: Catch a Giant Australian Cuttlefish in Gulf St Vincent for scientific study

Photo of Giant Australian Cuttlefish on deck of boat, grabbing a horsehoe leatherjacket

Have you ever caught a cuttlefish while fishing from shore or sea in Gulf St. Vincent, South Australia? Next time you catch one, you might like to consider donating it to science to help modern scientists complete a 172 year-old task that will enhance our understanding of Giant Australian cuttlefish, Australia-wide. Read on for background information, or skip to the end of the article for contact details if you catch one and are willing to donate it. This article will be updated once we have received roughly five male and five female cuttlefish specimens.

BACKGROUND

Since the late 1990s, the Giant Australian Cuttlefish aggregation that occurs each winter in South Australia’s upper Spencer Gulf has developed an international profile as a tourist attraction and bonafide natural wonder. But giant Australian cuttlefish occur right across temperate and sub-tropical Australia, and form numerous distinct populations- possibly even different species.

The northern Spencer Gulf cuttlefish population is the central subject of a forthcoming documentary film called Cuttlefish Country that we’ve been working on since 2011. In our research, we learned that many scientific questions about cuttlefish in Australia remain unanswered. There is a role to play for “citizen scientists” like you to help professional scientists fill these knowledge gaps and advance our understanding of life in the sea.

Understanding these populations, and determining whether they are distinct species or subspecies, begins with the art and science of taxonomy. For centuries, taxonomy has relied on naturalists collecting, observing, drawing and precisely noting the physical features of an animal or plant. Once published, this would then provide scientists worldwide with a visual and verbal “description” to compare other organisms with.

Taxonomy has allowed biologists worldwide to gradually figure out relationships within and between different groups of plants and animals. Once described, a species is given a unique scientific name, which may change in time as relationships between different animals are better understood. Advances in genetic analysis in recent decades have lead to many taxonomic “shuffles”, but a complete and detailed physical description of every organism is where the magic begins.

In the case of the Giant Australian Cuttlefish, Sepia apama, that work is incomplete. It was started in 1859 by the British zoologist, John Edward Gray, but the specimen he described was a cuttlebone only. This has complicated modern scientists’ efforts to compare the originally described population from Gulf St Vincent with populations elsewhere.

Before the Sepia apama record can be updated with a complete description of the animal, new specimens need to be collected from the same region where the original cuttlebone was collected: Gulf St Vincent. Those waters extend from Cape Jervis in the east to Port Wakefield in the north and Edithburgh in the west.

Scientists are ideally seeking a total of 5 male and 5 female specimens from these waters, which is where South Australia’s recreational fishers can help out. Our first specimen was supplied last week by Tony Bainbridge, who caught it offshore from Seaford (pictured above and below). Other fishers have caught them previously from jetties, kayaks and boats at locations like Rapid Bay, Second Valley, Moana, Port Noarlunga, Marino, Brighton and Outer Harbor.

HOW CAN I HELP?

If you catch a Giant Australian cuttlefish in Gulf St Vincent waters and are willing to donate it to science, please photograph it when you first catch it, then keep it refrigerated or frozen. Call or message me (Dan) on 0411039592 or send an email to dan@danimations.com.au . Please take note of the depth and location if you’re on a boat or kayak. I’ll arrange to collect it from you and deposit it at the South Australian Museum. The scientists there will take a tissue sample for genetic analysis and the body will be pickled and preserved for physical comparisons. You will be recorded as the collector.

Completing the taxonomic description of Sepia apama is a crucial step in understanding and classifying the Giant Australian cuttlefish populations of Australian waters and a great chance for fishos to help get this 172 year-old job done! I’ll be sure to keep all volunteers updated via Facebook as the project progresses. There is no deadline for providing specimens, so this call will remain open until we have a total of roughly five male and five female cuttlefish suitable for study.

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