''Juxtastenopus spinulatus'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of stenopodidean shrimp. It lives in the

Red Sea The Red Sea ( ar, البحر الأحمر - بحر القلزم, translit=Modern: al-Baḥr al-ʾAḥmar, Medieval: Baḥr al-Qulzum; or ; Coptic: ⲫⲓⲟⲙ ⲛ̀ϩⲁϩ ''Phiom Enhah'' or ⲫⲓⲟⲙ ⲛ̀ϣⲁⲣⲓ ''Phiom ǹšari''; T ...

, and across the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by th ...

as far east as the

Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

. It is red or pink, up to long, with enlarged third

pereiopod The decapod (crustaceans such as a crab, lobster, shrimp or prawn) is made up of 20 body segments grouped into two main body parts: the cephalothorax and the pleon (abdomen). Each segment may possess one pair of appendages, although in various g ...

s. Originally described in the genus '' Engystenopus'', it is now placed in the monotypic genus ''Juxtastenopus'', in the family

Stenopodidae Stenopodidae is a family of decapods in the order Decapoda. There are about 6 genera and more than 30 described species in Stenopodidae. Genera These six genera belong to the family Stenopodidae: * ''Juxtastenopus'' Goy, 2010 * '' Odontozona'' H ...

Description

''Juxtastenopus'' grows to a total body length of long (

carapace A carapace is a Dorsum (biology), dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tor ...

length: ). In life, the animals are red or pinkish, but with white tips to the

chelae A chela ()also called a claw, nipper, or pinceris a pincer (biology), pincer-like organ at the end of certain limbs of some arthropods. The name comes from Ancient Greek , through New Latin '. The plural form is chelae. Legs bearing a chela are ...

(claws) on the enlarged third pereiopods (walking legs). Females are reproductive at lengths around , and carry between 27 and 132 eggs, each initially in diameter.

Distribution

Most specimens of ''J. spinulatus'' have been collected from the

at depths of , where the water is warm. That warm water mass drops to a depth of on passing through the

Bab-el-Mandeb The Bab-el-Mandeb (Arabic: , , ) is a strait between Yemen on the Arabian Peninsula, and Djibouti and Eritrea in the Horn of Africa. It connects the Red Sea to the Gulf of Aden. Name The strait derives its name from the dangers attendin ...

strait into the

Gulf of Aden The Gulf of Aden ( ar, خليج عدن, so, Gacanka Cadmeed 𐒅𐒖𐒐𐒕𐒌 𐒋𐒖𐒆𐒗𐒒) is a deepwater gulf of the Indian Ocean between Yemen to the north, the Arabian Sea to the east, Djibouti to the west, and the Guardafui Channe ...

, and ''J. spinulatus'' has also been collected at a depth of in the Gulf of Aden. It also occurs in the

, and as far east as

Hong Kong Hong Kong ( (US) or (UK); , ), officially the Hong Kong Special Administrative Region of the People's Republic of China ( abbr. Hong Kong SAR or HKSAR), is a city and special administrative region of China on the eastern Pearl River Delt ...

and the

, but occurs in much shallower water than in the Red Sea.

Taxonomy

The earliest discovered specimens of ''J. spinulatus'' were assigned by Heinrich Balss to the species ''

Stenopus spinosus ''Stenopus spinosus'' is a shrimp-like decapod crustacean belonging to the infraorder Stenopodidea. Description ''Stenopus spinosus'' can grow up to long, and is chiefly yellow, with white antennae and white tips to the chelae (claws). The u ...

''. Its first description as a separate species was the

type description A species description is a formal description of a newly discovered species, usually in the form of a scientific paper. Its purpose is to give a clear description of a new species of organism and explain how it differs from species that have be ...

by Lipke Holthuis in 1946, where it was given the name ''Engystenopus spinulatus''. This was based on a single damaged

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

male, collected in the Lobetoli Strait, east of

Flores Flores is one of the Lesser Sunda Islands, a group of islands in the eastern half of Indonesia. Including the Komodo Islands off its west coast (but excluding the Solor Archipelago to the east of Flores), the land area is 15,530.58 km2, and th ...

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

, and the placement in the genus '' Engystenopus'' was considered questionable. The most distinctive characteristics of ''Engystenopus'' are characters of the third

, which was lacking from all the early specimens. When specimens with intact third pereiopods became available, Joseph Goy realised that "''E. spinulatus''" did not belong in the same genus as '' E. palmipes'' (the only other species of ''Engystenopus''), and erected a new genus, ''Juxtastenopus'', to hold it. The two genera are now placed in different families, although both names carry the meaning "close to '' Stenopus''"; ''Engystenopus'' is one of seven extant genera in the family

Spongicolidae Spongicolidae is a family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

, while ''Juxtastenopus'' is one of four extant genera in the family

References

External links

* * {{Taxonbar, from1=Q6319157, from2=Q18581552 Stenopodidea Monotypic arthropod genera