''Allopontonia brockii'' is a small

commensal Commensalism is a long-term biological interaction (symbiosis) in which members of one species gain benefits while those of the other species neither benefit nor are harmed. This is in contrast with mutualism, in which both organisms benefit fro ...

shrimp Shrimp are crustaceans (a form of shellfish) with elongated bodies and a primarily swimming mode of locomotion – most commonly Caridea and Dendrobranchiata of the decapod order, although some crustaceans outside of this order are refer ...

in the

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

Palaemonidae Palaemonidae is a family of shrimp in the order Decapoda. Many species are carnivores that eat small invertebrates, and can be found in any aquatic habitat except the deep sea. One significant genus is ''Macrobrachium'', which contains commerc ...

Description

This

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 ...

can be easily confused with ''

Allogalathea elegans ''Allogalathea elegans'' (known as the ''feather star squat lobster'', ''crinoid squat lobster'' or ''elegant squat lobster'') is a species of squat lobster that is sometimes kept in marine aquariums. Despite their common name, they are more c ...

'' (crinoid squat lobster) due to its long

cheliped A chela ()also called a claw, nipper, or pinceris a 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 called chelipeds. ...

s, the visible shape of its

cephalothorax The cephalothorax, also called prosoma in some groups, is a tagma of various arthropods, comprising the head and the thorax fused together, as distinct from the abdomen behind. (The terms ''prosoma'' and ''opisthosoma'' are equivalent to ''cepha ...

, its

abdomen The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso. ...

slightly curved under the body and by its colours. However, ''Allopontonia brockii'' differs in several points from ''Allogalathea elegans'': *its

rostrum Rostrum may refer to: * Any kind of a platform for a speaker: **dais **pulpit * Rostrum (anatomy), a beak, or anatomical structure resembling a beak, as in the mouthparts of many sucking insects * Rostrum (ship), a form of bow on naval ships * Ros ...

is ridged, sharp and notched, *its

s are smooth without spines. The body coloration varies from light yellow to orange–red with a wide whitish longitudinal stripe sometimes lined with a dark border. It reaches a maximum length of .

Distribution

''Allopontonia brockii'' is widespread through 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 ...

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 ...

included, and the eastern coast of the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

Ecology

''Allopontonia brockii'' is considered as a

species from different species of

sea urchin Sea urchins () are spiny, globular echinoderms in the class Echinoidea. About 950 species of sea urchin live on the seabed of every ocean and inhabit every depth zone from the intertidal seashore down to . The spherical, hard shells (tests) of ...

s like some of the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

'' Salmaciella'', ''

Salmacis Salmacis ( grc, Σαλμακίς) was an atypical Naiad nymph of Greek mythology. She rejected the ways of the virginal Culture of Greece, Greek goddess Artemis in favour of vanity and idleness. Mythology Ovid's version Salmacis' attempted ...

'', '' Asthenosoma'' or '' Pseudoboletiana''. However, ''Allopontonia brockii'' can usually be observed on ''

Asthenosoma varium ''Asthenosoma varium'' is a sea urchin (an echinoderm, a member of the phylum that also includes star fish). Growing up to in diameter, it lives on sand and rubble sea bottoms in the Indo-Pacific, from the Red Sea to Australia and Southern Japan ...

'' (fire sea urchin). ''Allopontonia brockii'' takes advantage of its host when it moves on the

substratum In linguistics, a stratum (Latin for "layer") or strate is a language that influences or is influenced by another through contact. A substratum or substrate is a language that has lower power or prestige than another, while a superstratum or sup ...

to collect its food during the way and also takes benefit of the potential food which can hang onto the sea urchin.

References

External links

* {{Taxonbar, from=Q13109066 Palaemonoidea Crustaceans of the Indian Ocean Crustaceans of the Pacific Ocean Crustaceans described in 1888 Taxa named by Johannes Govertus de Man