| Sepia australis | |
|---|---|
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Cephalopoda |
| Order: | Sepiida |
| Family: | Sepiidae |
| Genus: | Sepia |
| Subgenus: | Anomalosepia |
| Species: | S. australis |
| Binomial name | |
| Sepia australis | |
| Synonyms | |
Sepia australis, the southern cuttlefish, [1] is a species of cuttlefish which is found in the eastern South Atlantic Ocean and the western Indian Ocean off the coasts of Southern Africa, possibly extending into the waters off East Africa.
Sepia australis has widely-separated, posteriorly rounded fins. The arms have the suckers arranged in four series with the middle series of suckers consisting of slightly larger suckers than the lateral ones, this difference being more pronounced in male. The hectocotylus is found on the left ventral arm and has two rows of normal size suckers near its base, six or seven rows of greatly reduced suckers in the middle which become normal sized towards the tip of the arm. Suckers in two of the dorsal and two of the ventral series are laterally displaced and show a gap between them. The short tentacular club is crescent-shaped and has five suckers arranged in crosswise rows, these suckers show great differences in size with 3 very enlarged suckers near the base of the club. The swimming keel of the club, extends a very short distance towards the carpus at the club's base. The dorsal and ventral protective membranes are separate and are not connected at base of club. [3]
It has an oval cuttlebone which is bluntly rounded at its anterior end and has a sharp posterior end. It shows strong ventral recurving and the dorsal surface is convex, smooth and creamy white in colour. The bone's long, straight spine and posterior quarter are covered with an ochre-coloured smooth glaze. The dorsal median rib of the bone is indistinct and broadens slightly anteriorly; the bone's ribs are bordered laterally by obvious grooves and the lateral ribs are marked. The whole margin of the cuttlebone is surrounded by chitin. [3]
The overall colour is purplish-brown with pale fins which have a broad orange-pink band along their base dorsally while some pigment is present ventrally. There is a concentration of chromatophores near fins on both the dorsal and ventral surfaces of the cuttlefish's body. They grow up to 85 mm in mantle length and 50 g total weight. [3]
The species is known to occur in the south eastern Atlantic Ocean and the extreme south western Indian Ocean and is found from southern Namibia to Port Elizabeth in the Eastern Cape Province of South Africa. There are reports of records from further east and north as far as the Gulf of Aden. [1] The reports of this species off China, referred to as Sepia sinope by John Edward Gray are likely to be erroneous. [3]
Sepia australis can be found at depths of 45 to 345 m and is most numerous at 60 to 190 m. It thrives in regions where the oxygen levels are low and in the northernmost part of its range off Namibia the highest catches occur where oxygen levels in the water are between 1.5 ml per litre to 3.5 ml per litre and the temperature is around 9 °C. Mature cuttlefish are found off the southern coasts of South Africa in early winter and it is thought that this species' main spawning grounds are to be found in deeper water on the western flank of the Agulhas Bank. [1] Males mature earlier than females and are sexually reproductive for longer, increased temperatures accelerate sexual maturation and spawning. Spawning can occur all year, depending on the water temperature and the depth with the largest cuttlefish occurring in the cooler and deeper waters of the west. [4] A survey conducted in 1988 found that differences in size and maturity of S. australis in different areas were most strongly correlated to water temperature and that depth and longitude were also important factors. The results of this survey further indicated that the main spawning grounds of S. australis off the south coast of South Africa are situated in deeper water on the western side of the Agulhas Bank. [5]
An opportunistic predator, it takes both benthic and pelagic crustaceans, fish, and cephalopods. Crustaceans sampled from the stomachs of S. australis are often too well digested to identify but were mainly mysids, megalopae larvae, krill, and hyperiids, as well as some fish. Cannibalism has also been recorded, and this represented the only cephalopod prey recorded and this was more frequent in the eastern, less optimal, part of the species range. Fish species recorded as being preyed on by S. australis were identified using otoliths recovered with fish forming between 5% and 13% of the cuttlefish's diet. Species recorded included lanternfish Lampadena speculigera , tonguesole Cynoglossus zanzibarensis , ladder dragonet Paracallionymus costatus , the Cape hake Merluccius capensis and Cape conger Conger wilsoni. Krill make up just over half the volume of prey taken. Cannibalism and fish were more important in the diet in the east of its range than in the west, possibly as a result of a lower abundance of crustaceans in the east. [4]
This cuttlefish forms an important part of the diet of Cape fur seals, hake, skate and other commercially exploited whitefish. [1]
Sepia australis is not currently subject to commercial exploitation, but as an apparently abundant species with "tasty flesh", it may be of interest to fisheries in the future. [1]
The type specimen was collected during the second exploratory voyage of the Astrolabe , its first under the command of Jules Dumont d'Urville, which lasted from 1826 to 1829. It was described by Jean René Constant Quoy and Joseph Paul Gaimard in their 1932 account of the zoological collections of the expedition [2] and the type is lodged at the Museum National d'Histoire Naturelle in Paris. [6]
Cuttlebone, also known as cuttlefish bone, is a hard, brittle internal structure found in all members of the family Sepiidae, commonly known as cuttlefish, within the cephalopods. In other cephalopod families it is called a gladius.
Metasepia pfefferi, also known as the flamboyant cuttlefish, is a species of cuttlefish occurring in tropical Indo-Pacific waters off northern Australia, southern New Guinea, as well as numerous islands of the Philippines, Indonesia and Malaysia. The flesh of this colorful cephalopod contains unique acids, making it unsuitable for consumption.
Sepia latimanus, also known as the broadclub cuttlefish, is widely distributed from the Andaman Sea, east to Fiji, and south to northern Australia. It is the most common cuttlefish species on coral reefs, living at a depth of up to 30 m.
The common cuttlefish or European common cuttlefish is one of the largest and best-known cuttlefish species. They are a migratory species that spend the summer and spring inshore for spawning and then move to depths of 100 to 200m during autumn and winter. They grow to 49 cm in mantle length (ML) and 4 kg in weight. Animals from subtropical seas are smaller and rarely exceed 30 cm in ML.
Sepia mestus, also known as the reaper cuttlefish or red cuttlefish, is a species of cuttlefish native to the southwestern Pacific Ocean, specifically Escape Reef off Queensland to Murrays Beach off Jervis Bay. Reports of this species from China and Vietnam are now known to be misidentifications. S. mestus lives at a depth of between 0 and 22 m.
Sepia novaehollandiae is a species of cuttlefish native to the southern Indo-Pacific. Its natural range stretches from Shellharbour, New South Wales to North West Shelf in Western Australia. It lives at depths of between 15 and 348 m.
Sepia hedleyi, or Hedley's cuttlefish, is a species of cuttlefish in the family Sepiidae, endemic to subtropical and temperate waters off Australia.
Sepia tuberculata is a species of cuttlefish native to South African waters from Melkbosstrand to Knysna. It belongs to the genus Sepia. It lives in very shallow water to a depth of 3 m. It is endemic.
Sepia vermicularis, the patchwork cuttlefish.sometimes known as the common cuttlefish or ink-fish in South Africa, but the name common cuttlefish is more widely applied to Sepia officinalis. It is endemic to southern Africa.
Sepia zanzibarica, or the Zanzibar cuttlefish, is a species of cuttlefish native to the Indian Ocean.
Sepia prashadi, common name hooded cuttlefish, is a widely distributed species of cuttlefish. It has a thin, oval body and grows from 5 to 11 cm. The tips of the tentacles have a distinct club shape. S. prashadi is a migratory, demersal cuttlefish living in shallow waters at depths of approximately 40 to 50 metres. It is found in many locations including the east coast of Africa, around India, in the Red Sea, and Persian Gulf.
Sepia braggi, the slender cuttlefish, is a species of cuttlefish native to the Indo-Pacific Ocean. It has been found in coastal waters of southern Australia. This species was first collected in South Australia by its namesake, William Lawrence Bragg. Sepia braggi was then described by Sir Joseph Cooke Verco in 1907.Sepia braggi is part of the subgenus Doratosepion which contains to 41 species of cuttlefish in total.
Sepia elegans, the elegant cuttlefish, is a species of cuttlefish in the family Sepiidae from the eastern Atlantic Ocean and the Mediterranean Sea. It is an important species for fisheries in some parts of the Mediterranean where its population may have suffered from overfishing.
Sepia bertheloti, the African cuttlefish, is a species of cuttlefish from the family Sepiidae which is found in the warmer waters of the eastern Atlantic Ocean off Africa.
Sepia orbignyana, the pink cuttlefish, is a species of small cuttlefish from the family Sepiidae. It is occurs in the temperate and tropical waters of the eastern Atlantic Ocean.
Sepia hierredda, the giant African cuttlefish, is a species of cuttlefish from the family Sepiidae, which was previously considered conspecific with the common cuttlefish Sepia officinalis. It is found along the western coast of Africa and is an important species to fisheries.
Sepia cultrata, commonly known as the knifebone cuttlefish or elongated cuttlefish, is a species of cuttlefish from the family Sepiidae endemic to the southern Indo-Pacific. It is a deepwater species found in subtropical and temperate Australian waters.
Sepioloidea lineolata or more commonly known as the striped pyjama squid or the striped dumpling squid is a type of bottletail squid, that inhabits the Indo-Pacific Oceans of Australia. Although it is not quite a cuttlefish, as it does not have a cuttlebone, it is otherwise exactly the same as cuttlefish. Therefore it is a sepioid, not a real cuttlefish. However, it is usually referred to as a cuttlefish for public simplification. It is not a squid either. The striped pyjama squid lives on the seafloor and is both venomous and poisonous. When fully mature, a striped pyjama squid will only be about 7 to 8 centimeters in length. Baby striped pyjama squids can be smaller than 10mm.
Sepia lycidas, commonly known as the kisslip cuttlefish, is a species of cuttlefish within the genus Sepia. They are also classified under the family Sepiidae, which encompasses some of the most commonly known and recognized cuttlefish. Phylogenetically, this species of cuttlefish is most closely related to Sepia aculeata, Sepia esculenta, and Sepia pharaonis. This species is typically reddish brown to purple in color, with patches and stripes present on their dorsal mantle. On average, they grow to be about 38 cm in length and weigh 5 kg at maximum. The kisslip cuttlefish can be found mainly within the Indo-West Pacific, at depths ranging from 15–100 meters. Additionally, this species exhibits many diverse, complex reproductive behaviors; for example, courting, mating displays, and mate competition. Other interesting behaviors includes their feeding and hunting methods, which entails turning towards a preferred direction to "jump on" and engulf their prey of small fish and crustaceans. Sepia lycidas has many human uses and is important in the economy of many Southeast Asian countries, especially since they are often eaten for their high nutritional value. They are also currently being studied as an alternative source of collagen for human use, since their thick outer skin contain high levels of collagen that goes to waste when they are eaten or caught as bycatch.
