Unveiling the Octopus's Garden: The Surprising Diversity of Australian Cephalopods

Some of the most charismatic and curious creatures of the oceans, cephalopods represent a significant portion of the species that make up our marine ecosystems. In fact, the waters of Australia are home to some of the highest diversity of cephalopods in the world. Although including a wide array of distinctive animals such as octopuses, squid, nautiloids and cuttlefish, it is sometimes easy to forget the importance of this unusual group. Cephalopods are classified within the same phylum as the likes of snails, chitons and clams, although cephalopods are generally considered to be much more neurologically advanced than their relatives.

Image: CSIRO Publishing

Image: CSIRO Publishing

Taxonomist Dr Amanda Reid’s new text does much to reveal the varied roles that these organisms play. Functioning almost as a large, especially detailed field guide, Cephalopods of Australia and Sub-Antarctic Territories features 226 species of cephalopod and describes their habitat, biology, and distribution, amongst other aspects. With colour photographs, black and white drawings, and distribution maps, Reid’s work aptly explores why this class of animal is so important ecologically. Existing as both top-level predators and prey for species of fish, cetaceans and seabirds, there is much to be said for the influence that cephalopods have on their surrounding ecosystem.

In the comprehensive introduction to her book, Reid describes the publication as ‘timely’ and a means ‘to provide a solid launching pad for future studies and fisheries management.’ Cephalopods haven’t always been top marine predators – due to overfishing of finfish by humans, they now function as ‘a keystone group in understanding complex ecosystems’ based on their new position as significant marine predators. She hopes that this text will not just inform readers of what we already know about Australian cephalopods, but will ‘also indicate what we don’t know in order to identify potential future research projects.’

This is evident in the varying amounts of detail provided for each order of cephalopods, and the species within these orders. Some species profiles include reference to several research papers, whilst others contain more basic information with fewer references. There is still so much that we don’t know, and Reid is not afraid to demonstrate this.

An artist's impression of the luminiscent firefly squid  (Lycoteuthis lorigera ).  Image: Wikimedia Commons

An artist's impression of the luminiscent firefly squid (Lycoteuthis lorigera). Image: Wikimedia Commons

The nature of the guide is that it truly establishes the immense variety of species within the Cephalopoda class. It would have been no easy feat for Reid to encompass so much information into the one volume. Some standout species include Pfeffer’s flamboyant cuttlefish (Metasepia pfefferi), a vibrant organism with purple-pink patterning along their arms and distinctive, fleshy, flap-like papillae; the greater argonaut (Argonauta argo), a little-studied octopus species whose females look more like a nautilus when they create a paper-like egg case that wraps around their body in the same way that a nautilus shell does; and the crowned firefly squid (Lycoteuthis lorigera), a species possessing spectacularly luminescent photophores (light-producing organs) on several areas of their body.

And of course, some of the most well-known cephalopods found in Australia, the blue-ringed octopuses, of which there are actually more than one species: the blue-lined octopus (Hapalochlaena fasciata), the greater blue-ringed octopus (Hapalochlaena cf. lunulata) and the lesser blue-ringed octopus (Hapalochlaena maculosa). All three are incredibly venomous and have been involved in human fatalities, yet interestingly, the venom is not produced by the octopus themselves, but rather symbiotic bacteria found within them. A species known for its presence in our very own Port Phillip Bay, the Maori octopus (Octopus maorum) is also a fascinating species described that has been studied somewhat extensively.

A lesser blue-ringed octopus ( Hapalochlaena maculosa ) in the waters of Sydney.  Image: Sylke Rohrlach / Wikimedia Commons.

A lesser blue-ringed octopus (Hapalochlaena maculosa) in the waters of Sydney. Image: Sylke Rohrlach / Wikimedia Commons.

Although focused on information practically useful to researchers and fisheries experts, Reid’s text is still very relevant to those amateur naturalists out there, as well as to fishers and divers who want to know more about the marine world that they experience on a regular basis. It is important that we take responsibility for the often overlooked marine species that may be detrimentally affected into the future. It is concerning that there are so many species that we still know so little about – how can we know how they might be affected by human actions if we don’t even have all the information on their basic biology? But it is also refreshing to see the interest being taken in species of cephalopods in the hopes that more can be discovered, as is evident in the publication of such a comprehensive exploration of those organisms found here in Australian waters.  

This book belongs on your bookshelf if… you have a passion for marine ecosystems or are involved in the active management of Australian fisheries and wish to learn more about some of our country’s most significant marine creatures.

Head to the CSIRO Publishing website to purchase your copy. 

Rachel Fetherston

Rachel is an Arts and Science graduate and a freelance writer who is passionate about communicating the importance of the natural world through literature. She has completed an Honours year in Literary Studies, involving research into environmental philosophy and the significance of the non-human other. She is an editor and the Publications Manager for Wild Melbourne.

You can find her on Twitter at @RJFether.

Banner image of a Pfeffer's flamboyant cuttlefish courtesy of Jenny Huang / Wikimedia Commons.