Cuttlefish of South Australia
Before I embarked on the production of the documentary film Cuttlefish Country, I had little appreciation of the diversity of cuttlefish species which are found in South Australian waters. When I discuss cuttlebones with friends or strangers, I’m usually met with surprise at the revelation that cuttlebones found in beachwash along the South Australian coast represent not one, not two but several species of cuttlefish. It is also unfortunate that there is no single resource available whereby South Australian naturalists or beach combers can go to identify their cuttlebone discoveries, or increase their familiarity with local species. This is something I hope the Marine Life Society of South Australia can soon remedy.
Sepia chirotema – a nameless pelagic cuttlefish
Back in 2012 and 2013, on two separate trips to Kangaroo Island, Emma and I collected specimens of a cuttlebone of an unfamiliar shape. It was long and slender, and had a sharper, steeper bevel than the larger Sepia apama (Giant Australian cuttlefish) I was more familiar with. Back in 2012, I did not have any contacts at the South Australian museum, so I delivered the first batch of specimens to cephalopod expert, Mark Norman at the Victorian Museum. To date I am unsure if the specimens have been processed, or if any like it exist in that museum’s collection.
Yesterday, I took my second batch of specimens to the South Australian Museum, and with the assistance of marine invertebrates collection manager, Thierry Laperousaz, I was able to successfully identify the species. I deposited two specimens of Sepia chirotrema in the collection, a pelagic species, known to inhabit depths of 120-210 metres. Given the majority of South Australians live on the waters of our two, much shallower gulf systems, it is not surprising that specimens of this species from South Australia are few.
When I pulled open the drawer in the SAM’s compactus containing the matching dry cuttlebone specimens, Thierry and I noticed that at least one specimen had been collected near Mount Gambier. The holotype (the first specimen ever described) had been collected on the southern shore of Kangaroo Island- quite possibly near Vivonne Bay, the place of my earlier collection.
Importantly, neither of these locailties are currently represented on the species range map at the Atlas of Living Australia. The ALA’s records of the species are also limited, currently numbering 44, almost all of them from Western Australia. The ALA records range from the north west of Western Australia in a continuous band to the south then eastwards into the Great Australian Bight. The South Australian range of the species is currently underrepresented, which points to an exciting opportunity for a citizen science project.
On cuttlebones and citizen science
Last year, the South Australian Museum enlisted the help of numerous online volunteers, who transcribed specimen labels from the collection, creating new datasets of records for the ALA based on historic SAM specimens. The initative was a pleasure to participate in, and the labour of many volunteers resulted in the expansion of a far more complete distribution map in the ALA for a number of seastar species. I was pleased to hear back from Andrea Crowther recently that the SA Museum is considering planning another citizen science transcription ‘expedition’ digitising the dry cuttlebones in the collection in the near future.
In the meantime, what can the Atlas of Living Australia tell us about the cuttlefish of South Australia? While Sepia apama is a widely known iconic species (particularly to the waters of northern Spencer Gulf), others are far less well known or documented.
Sepia novaehollandiae and Sepia braggi, along with the larger Sepia apama are all caught to some extent as bycatch by the Spencer Gulf prawn trawl fishery. Presumably other specimens have been collected as beach-washed cuttlebones, or during other scientific or fisheries trawling activities. I’ve aggregated the limited available information on cuttlefish known to inhabit SA waters below, and look forward to expanding and revising this list in the future after my next visit to the SA Museum’s magnificent collection. It may well be that additional cuttlefish have been found in SA waters, but are yet to make it into range maps and occurrence databases- so the list below should not be taken to be exhaustive.
For the sake of simplicity, I’ve deliberately limited the table to the genus Sepia, thereby excluding the bob-tail and bottle-tail squids, pygmy squid and any other cephalopods which are sometimes referred to as ‘cuttlefish’. The term cuttlefish was previously used much more liberally to include octopus, squid, nautilus and cuttlefish. Depth and size data come from sources cited by the Australian Museum and/or Wikipedia pages on these species.
|Genus||Species||Common name||Max. mantle length (mm)||Min depth (m)||Max depth (m)||Described|
|Sepia||apama||Giant Australian cuttlefish||500||1*||?||1849, Gray|
|Sepia||braggi||Slender cuttlefish||49 (m) 80 (f)||30||86||1907, Verco|
|Sepia||cultrata||Knifebone cuttlefish or Elongated cuttlefish||120||132||803||1885, Hoyle|
|Sepia||hedleyi||Hedley’s cuttlefish||83 (m) 108 (f)||47||1092||1918, Berry|
|Sepia||novaehollandiae||New Holland cuttlefish||77||15||348||1909, Hoyle|
* Sepia apama minimum depth is based on personal observations. Other depth data comes from published sources.
As for the bob-tails and dumpling squids…
Okay- just so the bobtails don’t feel rejected by the limited scope of this article, here’s a video of one of the lesser known bobtails found in SA waters. Sepiadarium kochii is sometimes refered to as the ‘pop up squid’ and has quite a talent for digging.
Dan Monceaux is a documentary filmmaker with a keen interest in marine biodoversity and conservation issues. He joined MLSSA in 2013 and served as Secretary from April-December 2014. Dan snorkels and has burning passions for underwater photography and citizen science.
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