Sepia apama

Geographic Range

Sepia apama, known as the Australian giant cuttlefish, derives its common name from its geographical origin and nativity, Australia. More specifically, it lives in the coastal waters and bays extending from Ningaloo and Pointes Cloates in Western Australia, across Australia’s southern coast, and northward along the eastern coast to Shoalwater Bay in Queensland. Outside Australian waters, the cuttlefish is also native to the east Indian Ocean, and islands within the southwest Pacific Ocean. ("Fisheries | Cuttlefish", 2013)


Sepia apama inhabits coral reefs, rocky reefs, kelp forests, seagrass meadows, muddy and sandy areas. In general, cuttlefish live in shallow seas where sunlight is abundant and biomass of primary production is high. ("BBC Nature - Giant cuttlefish videos, news, and facts", 2013)

  • Range depth
    100 (low) m
    328.08 (low) ft

Physical Description

Sepia apama has a bulky body, with 10 appendages (8 short, heavy arms, and 2 larger extensible tentacles), highly developed eyes, and a reddish-brown skin with white spots on the arms and mantle. Along each side of the body, a long, pale lateral fin extends the length of the mantle; these fins are used in maneuvering. Cephalopods’ bodies are streamlined, making them efficient at swimming. In addition to their swimming abilities, they have the ability to change colors by the means of contracting or expanding pigments in special cells called chromatophores, located in the skin. (Hansford, 2013; Karleskint, et al., 2013)

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    10.5 (high) kg
    23.13 (high) lb
  • Range length
    50 (high) cm
    19.69 (high) in
  • Average basal metabolic rate
    unknown cm3.O2/g/hr


The development of S. apama is exhibited through two alternative life cycles for both females and males. One life cycle encompasses 7 to 8 months to reach maturity during the first summer; during this time, rapid juvenile growth takes place. In contrast to the first life cycle, the second alternative involves slower juvenile growth during the summer; instead of reaching maturity within 7 to 8 months, the cuttlefish reaches maturity within the second year. (Beeton, 2011)


Reproduction in the giant cuttlefish is promiscuous, characterized by large spawning aggregations, multiple mating and paternities, potential sperm competition, and female choice. Males elaborately use their color changing abilities to attract female males by flashing their chromatophores. Less dominant males disguise themselves by assuming female coloration and can "hide" among females until they find an opportunity to mate when the dominant males are distracted (the "sneaker male" reproductive phenomenon). (Norman, 2000; Norman, 2007; Payne, 2010)

As in all cephalopods, fertilization is internal, with the male transferring spermatophore packets into the female's mantle cavity using a specially modified arm called the hectocotylus. A female may mate several times with multiple males during a spawning aggregation. As the female spawns, the eggs are fertilized by sperm from the spermatophores that the male has attached near her oviduct, inside her mantle cavity. Cuttlefish do not feed during the breeding season, and after breeding, individuals die. (Karleskint, et al., 2013; Payne, 2010)

  • Breeding interval
    Females may mate several times in their lives.
  • Breeding season
    Reproduction takes place during several months of the Australian winter.
  • Range number of offspring
    100 to 300
  • Range gestation period
    3 to 5 months
  • Average time to independence
    0 minutes
  • Average age at sexual or reproductive maturity (female)
    1 years
  • Average age at sexual or reproductive maturity (male)
    1 years

After the egg capsules have been laid, the female cuttlefish abandons them and dies shortly after, so there is no further parental investment. (Norman and Reid, 2000)

  • Parental Investment
  • pre-hatching/birth
    • provisioning
      • female


This species is a terminal spawner. Individuals mature in one year and die after breeding, though there are reports of individuals having lived 2 years. (Beeton, 2011)

  • Range lifespan
    Status: wild
    2 (high) years
  • Average lifespan
    Status: wild
    1 years


Many aspects of the giant cuttlefish’s behavior can be observed through its dynamic ability in changing colors and patterns. While S. apama is generally solitary, they interact with conspecifics during mating season, when males attract females by flashing their chromatophores. Though cuttlefishes are colorblind, they can camouflage themselves in total darkness within seconds. This instantaneous skill is possible by blending simple colors in order to form a great variety of hues in conjunction with a layer of cells called leucophores, which reflect white light. The leucophores allow cuttlefishes to blend in with their environment by precisely matching the ambient light level and color without the animal even needing to use their eyes to detect the color environment around it. This species may display an innate curiosity towards SCUBA divers. (Hansford, 2013; Karleskint, et al., 2013; Norman and Reid, 2000; Norman, 2000; Norman, 2007)

Radiotracking studies of this species reveal that individuals spend more than 95% of the day resting, which suggests that they do not actively forage for food, but instead are lie-and-wait predators. (Aitken, et al., 2005)

  • Average territory size
    no territory cm^2

Home Range

Individuals do not seem to migrate daily or seasonally, except to return to their spawning grounds. Radiotracking studies revealed that one individual moved 65 km to return to the spawning aggregation in Spencer Gulf. (Payne, 2010)

Communication and Perception

Sepia apama is usually a solitary animal, but they communicate with other cuttlefishes during mating season. Even though a giant Australian cuttlefish has highly developed eyes, individuals are color blind. However, they communicate by contracting the chromatophores in their skin. Their perception of their surroundings is unmatchable due to the chromatophores and leucophores in their skin. (Hansford, 2013; Norman, 2000)

  • Other Communication Modes
  • mimicry

Food Habits

Small fish and crustaceans form the diet of this cuttlefish. When cuttlefishes are catching prey, they approach slowly and stealthily. When they are within striking distance, they thrust out their two tentacles (which are tucked away in a pouch located under their eyes) and seize their food in a fast, rapid motion. The tentacles then contract, bringing the prey item to the mouth, where the cuttlefish's arms enclose it. Cuttlefish also use their beaks to crack the shells of prawns and crabs, and their radula, lined with teeth, scrapes tissue so it can be swallowed. (Martin, 2010)

  • Animal Foods
  • fish
  • aquatic crustaceans


The unparalleled camouflaging ability of cuttlefish is their primary defense against predators. Not only are cuttlefish masters of color manipulation, but they also excel at changing the textural appearance of their integument. Unsurprisingly, this talent goes hand-in-hand with their ability to change body color, but they take their disguises to the next level by changing their body shape. Contraction of circular muscles in the integument allows the animal to “sculpt” their skin into different textures that resemble seaweed, debris, and other elements of the background environment, making the outline of their bodies less conspicuous. Nevertheless, they can fall prey to seabirds and marine mammals such as bottlenose dolphins. (Hansford, 2013)

  • Anti-predator Adaptations
  • mimic
  • cryptic

Ecosystem Roles

The Australian giant cuttlefish is a secondary and tertiary consumer in the neritic ecosystem; their feeding activities help regulate the populations of their fish and crustacean prey. The cuttlefish in turn serves as prey for sea birds, sharks, dolphins, and pinnipeds. (Hansford, 2013)

Sepia apama is known to host dicyemid parasites (phylum Rhombozoa: Dicyemida) within the organs of its renal system. (Catalano, 2013)

Commensal/Parasitic Species
  • Dicyemid mesozoans (phylum Rhombozoa)
  • Dicyema coffinense
  • Dicyema koinonum
  • Dicyema multimegalum
  • Dicyemennea spencerense

Economic Importance for Humans: Positive

The main economic utilization of S. apama is as food and bait. They are caught incidentally as by-catch in trawl fisheries, and on a small-scale using jigs, hooks, and spears. The inner shells ("cuttlebones") are used in the pet trade; captive birds like parakeets, parrots (Psittaculidae) and canaries (genus Serinus) use the soft, calcareous material to clean and sharpen their beaks. The spawning aggregations that occur annually in Spencer Gulf, South Australia attract hundreds of divers, scientists, and ecotourists to view this spectacular event. (Norman and Reid, 2000; Payne, 2010)

  • Positive Impacts
  • food
  • body parts are source of valuable material
  • ecotourism

Economic Importance for Humans: Negative

There are no known adverse effects of Sepia apama on humans.

Conservation Status

Sepia apama is characterized as "near threatened" by the IUCN, with a decreasing population. This is due to intense fishing in a few areas that have significantly decreased the population. While localized, since this species lives for only a couple years, and dies shortly after reproducing, the stability of their species could be significantly impacted if too many cuttlefish are removed. To combat this, the locations where S. apama aggregates to spawn annually in northern Spencer Gulf, South Australia, have been under management protection since 1998, when the area was closed to fishing. ("Molluscs of commercial, recreational, cultural and ecological significance", 2006; Barratt and Allcock, 2012)


Dianne Aglibot (author), San Diego Mesa College, Paul Detwiler (editor), San Diego Mesa College, Angela Miner (editor), Animal Diversity Web Staff.


Pacific Ocean

body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.

World Map


Referring to an animal that lives on or near the bottom of a body of water. Also an aquatic biome consisting of the ocean bottom below the pelagic and coastal zones. Bottom habitats in the very deepest oceans (below 9000 m) are sometimes referred to as the abyssal zone. see also oceanic vent.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.


an animal that mainly eats meat


uses smells or other chemicals to communicate


the nearshore aquatic habitats near a coast, or shoreline.


active at dawn and dusk


having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

  1. active during the day, 2. lasting for one day.

humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.


animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature


union of egg and spermatozoan


A substance that provides both nutrients and energy to a living thing.


having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

internal fertilization

fertilization takes place within the female's body


imitates a communication signal or appearance of another kind of organism


having the capacity to move from one place to another.


specialized for swimming

native range

the area in which the animal is naturally found, the region in which it is endemic.


active during the night


reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.


an animal that mainly eats fish


the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.


structure produced by the calcium carbonate skeletons of coral polyps (Class Anthozoa). Coral reefs are found in warm, shallow oceans with low nutrient availability. They form the basis for rich communities of other invertebrates, plants, fish, and protists. The polyps live only on the reef surface. Because they depend on symbiotic photosynthetic algae, zooxanthellae, they cannot live where light does not penetrate.

saltwater or marine

mainly lives in oceans, seas, or other bodies of salt water.

seasonal breeding

breeding is confined to a particular season


offspring are all produced in a single group (litter, clutch, etc.), after which the parent usually dies. Semelparous organisms often only live through a single season/year (or other periodic change in conditions) but may live for many seasons. In both cases reproduction occurs as a single investment of energy in offspring, with no future chance for investment in reproduction.


reproduction that includes combining the genetic contribution of two individuals, a male and a female


lives alone


uses touch to communicate


the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.


movements of a hard surface that are produced by animals as signals to others


uses sight to communicate


2013. "BBC Nature - Giant cuttlefish videos, news, and facts" (On-line). Accessed September 22, 2013 at

2013. "Fisheries | Cuttlefish" (On-line). Accessed September 10, 2013 at

Department of the Environment and Water Resources. Molluscs of commercial, recreational, cultural and ecological significance. 4.12. Kingston, Tasmania: Commonwealth of Australia. 2006. Accessed December 12, 2013 at

Aitken, J., R. O'Dor, G. Jackson. 2005. The secret life of the giant Australian cuttlefish Sepia apama (Cephalopoda): behaviour and energetics in nature revealed through radio acoustic positioning and telemetry (RAPT). J. Exp. Mar. Biol. Ecol, 320: 77-91.

Barratt, I., L. Allcock. 2012. "Sepia apama" (On-line). The IUCN Red List of Threatened Species. Version 2014.2. Accessed July 26, 2014 at

Beeton, R. 2011. "Advice to the Minister for Sustainability, Environment, Water, Population and Communities from the Threatened Species Scientific Committee (the Committee) on Amendment to the list of Threatened Population under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act)" (On-line pdf). Accessed October 20, 2013 at

Catalano, S. 2013. Five new species of dicyemid mesozoans (Dicyemida: Dicyemidae) from two Australian cuttlefish species, with comments on dicyemid fauna composition. Systematic Parasitology, 86/2: 125-151.

Hansford, D. 2013. "Cuttlefish Change Color, Shape-Shift to Elude Predators" (On-line). Accessed October 10, 2013 at

Karleskint, G., R. Turner, J. Small. 2013. Introduction to Marine Biology, Fourth Edition. Belmont, CA: Brooks/Cole, Cengage Learning.

Martin, N. 2010. "Species Spiels: Giant Australian Cuttlefish (Sepia apama)" (On-line). Accessed November 13, 2013 at

Naud, M., R. Hanlon, K. Hall, P. Shaw, J. Havenhand. 2004. Behavioural and genetic assessment of reproductive success in a spawning aggregation of the Australian giant cuttlefish, Sepia apama. Animal Behaviour, 67/6: 1043-1050.

Norman, M. 2000. Cephalopods - A World Guide. Germany (Hackenheim): ConchBooks.

Norman, M., A. Reid. 2000. A Guide to Squid, Cuttlefish and Octopuses of Australasia. Victoria (Collingwood): CSIRO Publishing.

Norman, M. 2007. "Species Bank" (On-line). Accessed September 22, 2013 at

Payne, N. 2010. Approaches to Understanding the Population Dynamics and Behaviour of Sepia apama in Northern Spencer Gulf. University of Adelaide, South Australia: Unpublished thesis. Accessed December 12, 2013 at