''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 reef A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups. C ...

s, living at a depth of up to 30 m.

Naming and taxonomy

The

type specimen In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes th ...

of ''Sepia latimus'' was collected in

New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; id, Papua, or , historically ) is the world's second-largest island with an area of . Located in Oceania in the southwestern Pacific Ocean, the island is separated from Australia by the wide Torr ...

and is deposited at the

Muséum National d'Histoire Naturelle The French National Museum of Natural History, known in French as the ' (abbreviation MNHN), is the national natural history museum of France and a ' of higher education part of Sorbonne Universities. The main museum, with four galleries, is loc ...

Paris Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), ma ...

. This species has a wide geographic range and it is probable that it represents a

species complex In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

rather than a single species but more taxonomic work needs to be carried out to assess its species limits. The

World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive list of names of marine organisms. Content The content of the registry is edited and maintained by scientific specialis ...

lists the broadclub cuttlefish under the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

''Ascarosepion''; within this genus it is grouped with 13 other species, such as the ''Metasepia'' cuttlefish, the reaper cuttlefish, and the

giant cuttlefish Giant cuttlefish also known as the Australian giant cuttlefish (scientific name ''Sepia apama''), is the world's largest cuttlefish species, growing to in mantle length and up to in total length (total length meaning the whole length of the ...

Description

The broadclub cuttlefish is the second largest cuttlefish species after ''

Sepia apama Giant cuttlefish also known as the Australian giant cuttlefish (scientific name ''Sepia apama''), is the world's largest cuttlefish species, growing to in mantle length and up to in total length (total length meaning the whole length of the ...

'', growing to in mantle length and in weight.Reid, A., P. Jereb, & C.F.E. Roper 2005. Family Sepiidae. ''In:'' P. Jereb & C.F.E. Roper, eds. ''Cephalopods of the world. An annotated and illustrated catalogue of species known to date. Volume 1. Chambered nautiluses and sepioids (Nautilidae, Sepiidae, Sepiolidae, Sepiadariidae, Idiosepiidae and Spirulidae)''. FAO Species Catalogue for Fishery Purposes. No. 4, Vol. 1. Rome, FAO. pp. 57–152. Like many cephalopods, the broadclub can be seen displaying a range of colors and textures. Commonly they are light brown or yellowish with white mottled markings. Males are sometimes dark brown, particularly during courtship and mating. The arms have longitudinal white bands that appear as broad white blotches when extended. Some arms have longitudinal brown bands that extend to the head. The dorsal mantle can sometimes be seen with a saddle mark with small white and brown spots. The dorsal mantle also has narrow brown transverse bands, and bold, white, transverse stripes and spots. The eyes are yellow around the ventral margins and the fins are pale with white, transverse stripes extending onto mantle and narrow, white bands along outer margins.

Distribution

''Sepia latimanus'' has a wide distribution in the Indo-Pacific region from the coasts of eastern Africa in the west following the continental coastline through southern Asia to southern Japan and as far south as northern Australia and the Coral Sea. Records from southern Australia and Madagascar are thought to be most likely misidentifications.

Habitat and biology

''Sepia latimanus'' is a coastal species occurring in coral reefs and which is found in shallow water to depths of 30 m. In the western Pacific, off

Guam Guam (; ch, Guåhan ) is an organized, unincorporated territory of the United States in the Micronesia subregion of the western Pacific Ocean. It is the westernmost point and territory of the United States (reckoned from the geographic cent ...

and off

Okinawa is a prefecture of Japan. Okinawa Prefecture is the southernmost and westernmost prefecture of Japan, has a population of 1,457,162 (as of 2 February 2020) and a geographic area of 2,281 km2 (880 sq mi). Naha is the capital and largest city ...

in the shallows from January to May, and the resultant eggs hatch in 38 to 40 days. It is diurnal species which appears to mesmerise its prey by using a display consisting of a series of rhythmic colour bands running along its body. It preys on fishes and crustaceans and it is known to prey on shrimp and

prawn Prawn is a common name for small aquatic crustaceans with an exoskeleton and ten legs (which is a member of the order decapoda), some of which can be eaten. The term "prawn"Mortenson, Philip B (2010''This is not a weasel: a close look at nature' ...

s of the genus '' Palaemon''.Boletzky S.v. & R.T. Hanlon. 1983. A Review of the Laboratory Maintenance, Rearing and Culture of Cephalopod Molluscs. Memoirs of the National Museum of Victoria: Proceedings of the Workshop on the Biology and Resource Potential of Cephalopods, Melbourne, Australia, 9–13 March 1981, Roper, Clyde F.E., C.C. Lu &F.G. Hochberg, ed. 44: 147-187. Breeding males are territorial and defend a coral head, typically ''

Porites ''Porites'' is a genus of stony coral; they are small polyp stony (SPS) corals. They are characterised by a finger-like morphology. Members of this genus have widely spaced calices, a well-developed wall reticulum and are bilaterally symmetr ...

'', the females lay eggs following mating in the territory of the male. Their

courtship Courtship is the period wherein some couples get to know each other prior to a possible marriage. Courtship traditionally may begin after a betrothal and may conclude with the celebration of marriage. A courtship may be an informal and private m ...

is highly ritualized and stereotyped, and like their hunting behaviour it includes striking visual displays. The males frequently guard the females, defending them from other males. The male and female mate head-to-head, the male placing the

spermatophore A spermatophore or sperm ampulla is a capsule or mass containing spermatozoa created by males of various animal species, especially salamanders and arthropods, and transferred in entirety to the female's ovipore during reproduction. Spermatophores ...

s in the

buccal membrane The oral mucosa is the mucous membrane lining the inside of the mouth. It comprises stratified squamous epithelium, termed "oral epithelium", and an underlying connective tissue termed '' lamina propria''. The oral cavity has sometimes been des ...

of the female below to the mouth. After laying the eggs harden and are very hard to remove from the coral on which the female laid them. After hatching the young cuttlefish start to hide among the coral and the associated coral rubble where they often mimic

mangrove A mangrove is a shrub or tree that grows in coastal saline or brackish water. The term is also used for tropical coastal vegetation consisting of such species. Mangroves are taxonomically diverse, as a result of convergent evolution in severa ...

leaves, their coloration and posture impersonating the leaf structure with a stem, ribs and a scattering of black spots.

References

External links