''Idiosepius pygmaeus'', also known as the two-toned pygmy squid or tropical pygmy squid, is a species of

bobtail squid Bobtail squid (order Sepiolida) are a group of cephalopods closely related to cuttlefish. Bobtail squid tend to have a rounder mantle (mollusc), mantle than cuttlefish and have no cuttlebone. They have eight suckered arms and two tentacles and ar ...

native to the

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

. It occurs in the waters of the

South China Sea The South China Sea is a marginal sea of the Western Pacific Ocean. It is bounded in the north by South China, in the west by the Indochinese Peninsula, in the east by the islands of Taiwan island, Taiwan and northwestern Philippines (mainly Luz ...

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

Philippines The Philippines, officially the Republic of the Philippines, is an Archipelagic state, archipelagic country in Southeast Asia. Located in the western Pacific Ocean, it consists of List of islands of the Philippines, 7,641 islands, with a tot ...

Palau Palau, officially the Republic of Palau, is an island country in the Micronesia subregion of Oceania in the western Pacific Ocean. The Republic of Palau consists of approximately 340 islands and is the western part of the Caroline Islands ...

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian Ocean, Indian and Pacific Ocean, Pacific oceans. Comprising over List of islands of Indonesia, 17,000 islands, including Sumatra, ...

, the

Northern Mariana Islands The Northern Mariana Islands, officially the Commonwealth of the Northern Mariana Islands (CNMI), is an Territories of the United States, unincorporated territory and Commonwealth (U.S. insular area), commonwealth of the United States consistin ...

, as well as northern and northeastern

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

. It inhabits shallow,

inshore waters {{Short description, Coastlines used in weather forecasting The inshore coastal areas of the United Kingdom are 15 fixed stretches of coastline that are used in weather forecasting especially for wind-powered or small coastal craft. Each area is d ...

.Reid, A. 2005. Family Idiosepiidae. ''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. 208–210. ''I. pygmaeus'' weighs 0.00033 g upon hatching and increases in weight to 0.175 g as it reaches maturity in 50 days (1260

degree day A degree day is a measure of heating or cooling. Total degree days from an appropriate starting date are used to plan the planting of crops and management of pests and pest control timing. Weekly or monthly degree-day figures may also be used wi ...

s). It inhabits waters at a temperature of 25.2 °C. Growth rate has been calculated as 12.55 and physiological growth rate as 0.498. ''I. pygmaeus'' grows to a mantle length of 20 mm. This species has been reared on a diet of

glass shrimp ''Palaemon'' is a genus of Caridea, caridean shrimp in the family (biology), family Palaemonidae. Some species, including ''Palaemon macrodactylus'' and ''Palaemon orientis'', can inhabit fish ponds where they compete with fish for food and can ...

('' Acetes sibogae australis'') in the laboratory.Jackson, G.D. 1988. The Use of Statolith Microstructures to Analyze Life-history Events in the Small Tropical Cephalopod ''Idiosepius pygmaeus''. ''Fishery Bulletin'' (U.S.) 87: 265-272. The

type specimen In biology, a type is a particular wikt:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally associated. In other words, a type is an example that serves to ancho ...

was collected in the

() and is deposited at the Zoologisk Museum of

Kobenhavns Universitet The University of Copenhagen (, KU) is a public research university in Copenhagen, Denmark. Founded in 1479, the University of Copenhagen is the second-oldest university in Scandinavia, after Uppsala University. The University of Copenhagen co ...

Copenhagen Copenhagen ( ) is the capital and most populous city of Denmark, with a population of 1.4 million in the Urban area of Copenhagen, urban area. The city is situated on the islands of Zealand and Amager, separated from Malmö, Sweden, by the ...

.Current Classification of Recent Cephalopoda
/ref> ''Idiosepius pygmaeus'' is heavily concentrated in

seagrass meadow A seagrass meadow or seagrass bed is an underwater ecosystem formed by seagrasses. Seagrasses are marine (saltwater) plants found in shallow coastal waters and in the brackish waters of estuaries. Seagrasses are flowering plants with stems and ...

s. They are known to attach to seagrass using a special organ that supports adhesion. However, due to environmental changes caused by human activities, seagrass meadows have been disturbed. This habitat used for shelter by organisms such as Idiosepius is being threatened.

References

External links

Latitude and Longitude Data for ''Idiosepius pygmaeus''

GenBank Links for Genetic Information on ''Idiosepius pygmaeus''
* Idiosepius Bobtail squid Cephalopods described in 1881 {{Squid-stub

References

Further reading

External links