Animal Diversity Web

Ge­o­graphic Range

Sexy shrimp are most com­monly found in areas of the At­lantic and Indo-Pa­cific Oceans. Spe­cific lo­cal­i­ties in­clude the At­lantic coast of Florida and Gulf of Mex­ico, Caribbean Sea, and areas around Hawaii, the west­ern coast of Africa, French Poly­ne­sia, Mozam­bique, Tai­wan, China, the Ca­nary Is­lands, New Cale­do­nia, and within the Red Sea. ("Com­mon and Sci­en­tific Names of Aquatic In­ver­te­brates from the United States and Canada: De­ca­pod Crus­taceans", 2005; "The of­fi­cial site for Thor am­bione­sis", 2010; "Thor am­boinen­sis", 2009; De­Grave, et al., 2013)

• Biogeographic Regions
• nearctic
  • native
• palearctic
  • native
• oriental
  • native
• ethiopian
  • native
• australian
  • native
• indian ocean
  • native
• atlantic ocean
  • native
• pacific ocean
  • native

• Other Geographic Terms
• holarctic

Habi­tat

Sexy shrimp re­quire water tem­per­a­tures of 22-27°C . These shrimp form sym­bi­otic re­la­tion­ships with anemones such as En­tac­maea quadri­color, Macro­dactyla doreen­sis, Sti­chodactyla tape­tum, and Zoan­thus sp., liv­ing on and around their oral discs, ten­ta­cles, or sub­strate very near to anemone bases. Al­though some pop­u­la­tions seem to ex­hibit a slight pref­er­ence for cer­tain anemone species, on the whole they are con­sid­ered gen­er­al­ists as far as which species they de­velop re­la­tion­ships with. Most often, only one or two shrimp live on and in a host, but in some pop­u­la­tions as many as 11-18 in­di­vid­u­als have been ob­served in­hab­it­ing one anemone. These shrimp typ­i­cally live where there is gen­tle to mod­er­ate water move­ment, al­though they are ca­pa­ble of with­stand­ing strong cur­rents as well. Sexy shrimp can be found in depths rang­ing from 0.5-2.8 m. ("The of­fi­cial site for Thor am­bione­sis", 2010; "Thor am­boinen­sis", 2009; Baeza and Piantoni, 2010; De­Grave, et al., 2013; Guo, et al., 1996)

• Habitat Regions
• temperate
• tropical
• saltwater or marine

• Aquatic Biomes
• reef
• coastal

• Range depth

  0.5 to 2.8 m

  1.64 to 9.19 ft

Phys­i­cal De­scrip­tion

Sexy shrimp are very small, rang­ing in length from 1.5-13 mm. Base body color is drab (olive or brown), with iri­des­cent yel­low-white spots bor­dered by thin white and blue bands, sym­met­ri­cally arranged over their bod­ies. They have five pairs of pere­opods (tho­racic ap­pendages) and five pairs of pleopods (swim­ming legs). Their first pair of pleopods are en­larged into chelae, used for both in­tra- and in­ter­spe­cific in­ter­ac­tion. Their sec­ond ab­dom­i­nal seg­ment is greatly en­larged; fe­males carry de­vel­op­ing eggs under this seg­ment. Sexy shrimp have a tel­son and uropods, which form a fan­like tail, which is glossy and light brown in color, and is used for steer­ing while swim­ming. They have white eyes, lo­cated at the ends of short stalks. This species dif­fers from oth­ers in that, when at rest, their ab­domens and tails arch up­ward to­wards the head. ("The of­fi­cial site for Thor am­bione­sis", 2010; "Thor am­boinen­sis", 2009; Baeza and Piantoni, 2010)

Sexy shrimp dis­play sex­ual di­mor­phism in a num­ber of ways. Males are typ­i­cally smaller than fe­males and have gono­pores lo­cated on their fifth pere­opods, with paired testes and lat­eral sperm ducts. Males have ap­pen­dices mas­culi­nae, which are male or­gans used in cop­u­la­tion or sper­matophore trans­fer, lo­cated on their sec­ond pleopods. Fe­males have gono­pores on their third pere­opods and paired ovaries lo­cated above their he­patopan­creas. They also have white spots on their pleopods. (Baeza and Piantoni, 2010)

• Other Physical Features
• ectothermic
• bilateral symmetry

• Sexual Dimorphism
• female larger
• sexes colored or patterned differently
• sexes shaped differently

• Range length

  1.5 to 13 mm

  0.06 to 0.51 in

De­vel­op­ment

Most in­for­ma­tion re­gard­ing mat­ing and de­vel­op­ment of this species comes from ob­ser­va­tions by aquar­ium en­thu­si­asts. Eggs are light brown in color and are cared for as they de­velop by the fe­male, who car­ries them on her pleopods and con­tin­u­ally cleans and aer­ates them. Within 2-3.5 weeks after fer­til­iza­tion, eggs hatch, usu­ally at night. Lar­vae are tiny and slen­der, av­er­ag­ing about 2 mm in length, and are pho­to­taxic upon hatch­ing. They drift in ocean cur­rents for 20-30 days as they de­velop, un­der­go­ing 10-12 dif­fer­ent lar­val stages, with phys­i­cal changes oc­cur­ring in each stage. Larve molt every 2 to 3 days, most often at night. Al­though lar­vae even­tu­ally set­tle on a host anemone, they do not re­quire a chem­i­cal cue from a cer­tain host to do so; it has been hy­poth­e­sized that in­di­vid­u­als set­tle first and seek out an ap­pro­pri­ate host sec­ond. In cap­tiv­ity, meta­mor­pho­sis and set­tling have been ob­served to occur within 26 days of hatch­ing. ("Breed­ing Jour­nal: Species Thor am­boinen­sis", 2011; "The of­fi­cial site for Thor am­bione­sis", 2010; Sarver, 1979)

Sexy shrimp are protan­dric her­maph­ro­dites; re­searchers sus­pect that there are no pri­mary fe­males but that all in­di­vid­u­als are born male and tran­si­tion into fe­males later in life. (Baeza and Piantoni, 2010)

• Development - Life Cycle
• metamorphosis

Re­pro­duc­tion

Sexy shrimp ap­pear to ex­hibit a "pure-search" strat­egy for mat­ing, in which males search con­tin­u­ously for fe­males and then, with no courtship, the pair rapidly cop­u­late. It is as­sumed that at this point the pair sep­a­rate quickly, al­though re­ports from cap­tive breed­ers in­di­cate that males may guard fe­males once they re­lease eggs. It is un­known if fe­males are pas­sive or ac­tive re­gard­ing mate choice. Dur­ing cop­u­la­tion, a male trans­fers sperm cells from his gono­pores (lo­cated on his fifth pere­opods) to a fe­male's gono­pores (on her third pere­opods). The ap­pen­dices mas­culi­nae may aid in this trans­fer. ("Breed­ing Jour­nal: Species Thor am­boinen­sis", 2011; "The of­fi­cial site for Thor am­bione­sis", 2010; Baeza and Piantoni, 2010)

• Mating System
• polygynandrous (promiscuous)

Lit­tle is known about the re­pro­duc­tive cycle of this species in the wild. Sexy shrimp are ca­pa­ble of breed­ing year-round in cap­tiv­ity, as­sum­ing that en­vi­ron­men­tal con­di­tions are kept at con­sis­tently op­ti­mal lev­els. These shrimp are protan­dric hermaprhodites; they are born male and may change into fe­males later in life. Tran­si­tional in­di­vid­u­als, ex­hibit­ing char­ac­ter­is­tics of both sexes, have been found in the wild (tran­si­tional in­di­vid­u­als most closely re­sem­ble fe­males phys­i­cally). Males can change into fe­males in rel­a­tively short pe­ri­ods of time (less than 23 days); typ­i­cally, larger males are the ones who un­dergo sex change. ("The of­fi­cial site for Thor am­bione­sis", 2010; Baeza and Piantoni, 2010)

• Key Reproductive Features
• iteroparous
• year-round breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sequential hermaphrodite
  • protandrous
• sexual
• fertilization
  • internal
• oviparous

• Breeding interval

  Sexy shrimp may breed multiple times throughout the year.

• Breeding season

  Breeding season may be year round, under optimal environmental conditions, as well as in captivity.

• Range number of offspring

  200 to 500

• Range gestation period

  2 to 3.5 weeks

Fe­males carry, clean, and oxy­genate eggs under their for­ward tail sec­tion, on the pleopods. While bear­ing eggs, they hold their legs under the tail to pro­tect them. There is no known parental in­vest­ment by males. ("The of­fi­cial site for Thor am­bione­sis", 2010; Baeza and Piantoni, 2010)

• Parental Investment
• precocial
• female parental care
• pre-hatching/birth
  • protecting
    • female

Lifes­pan/Longevity

The av­er­age lifes­pan of sexy shrimp is thought to be about 3.5 years in the wild, but they are known to live up to 5 years. Lit­tle is de­fin­i­tively known of their ex­pected lifes­pan in cap­tiv­ity due to lim­it­ing fac­tors, such as tank en­vi­ron­ment. ("The of­fi­cial site for Thor am­bione­sis", 2010)

• Typical lifespan
  Status: wild

  5 (high) years

• Average lifespan
  Status: wild

  3.5 years

Be­hav­ior

Sexy shrimp are known to vi­brate their ab­domen to sig­nal or warn oth­ers. They are ca­pa­ble of mov­ing very quickly, at rates of 10-15 cm/s, to es­cape per­ceived threats. ("The of­fi­cial site for Thor am­bione­sis", 2010; "Thor am­boinen­sis", 2009)

Sexy shrimp are usu­ally found in pairs or in small groups on a sin­gle anemone host. There do not ap­pear to be any com­plex so­cial hi­er­ar­chies at play within groups. When an un­ac­cli­mated shrimp is in­tro­duced to an anemone, it will en­dure the at­tacks from the anemones' ne­ma­to­cysts. Some stud­ies state that a shrimp ac­cli­mates to an anemone by col­lect­ing its mucus, which cam­ou­flages it from the anemone. Other stud­ies say that a shrimp ac­cli­mates by build­ing up chem­i­cals that in­hibit the ex­cre­tions of ne­ma­to­cysts from anemones. It is un­cer­tain how long it takes for a shrimp to be­come ac­cli­mated to a host anemone, but it is known that these shrimp are gen­er­al­ists, not re­quir­ing par­tic­u­lar species of anemones as hosts. The spa­tial and tem­po­ral dis­tri­b­u­tion of shrimp de­pends upon their feed­ing ac­tiv­i­ties and the de­gree of anemone ex­pan­sion. (Baeza and Piantoni, 2010; Guo, et al., 1996; Khan, et al., 2004; Michael, 2012; Wirtz, 1997)

• Key Behaviors
• natatorial
• diurnal
• nocturnal
• motile
• sedentary
• social

Home Range

Al­though spe­cific home ranges have not been iden­ti­fied for these shrimp, in­di­vid­u­als tend to stay within a few cen­time­ters of their anenome host. They do not ap­pear to de­fend ter­ri­to­ries. (Baeza and Piantoni, 2010)

Com­mu­ni­ca­tion and Per­cep­tion

Sexy shrimp se­lect a host anemone by using vi­sual and chem­i­cal cues. They use their first pair of chelae for in­ter­sex­ual com­mu­ni­ca­tion and may make a sound to sig­nal oth­ers or to grab a fe­male. Lit­tle else is known about how sexy shrimp com­mu­ni­cate with each other but other shrimp species are known to emit sex pheromones, which can be per­ceived by both sexes. They have an­ten­nu­lar fla­gella, the func­tion of which is not fully known, but which are sus­pected to play a role as chemore­cep­tors. Sexy shrimp also sense their en­vi­ron­ments through tac­tile means, using their an­ten­nae. ("The of­fi­cial site for Thor am­bione­sis", 2010; Baeza and Piantoni, 2010; Bauer, 2001; Guo, et al., 1996)

• Communication Channels
• visual
• tactile
• chemical

• Other Communication Modes
• pheromones

• Perception Channels
• visual
• tactile
• chemical

Food Habits

Sexy shrimp are car­niv­o­rous. These shrimp feed on mat­ter trapped in a host anemone's mucus, in­clud­ing plank­ton. Their diet may also in­clude other small crus­taceans, such as brine shrimp (Artemia sp.), Mysida sp., and krill (Eu­phau­si­acea sp.). When re­sources are scarce, shrimp may re­sort to feed­ing on the ten­ta­cles of their hosts. ("Thor am­boinen­sis", 2009; Baeza and Piantoni, 2010)

• Primary Diet
• carnivore
  • eats non-insect arthropods
  • eats other marine invertebrates
• planktivore

• Animal Foods
• aquatic crustaceans
• other marine invertebrates
• zooplankton

• Plant Foods
• macroalgae

Pre­da­tion

Var­i­ous fishes are preda­tors of sexy shrimp. They avoid pre­da­tion by re­ly­ing on their hosts, who are ca­pa­ble of sting­ing and some­times con­sum­ing po­ten­tial preda­tors. Also, their vi­brant col­ors allow them to blend in with their en­vi­ron­ments. If threat­ened out­side of their anemone host, these shrimp have been ob­served to flip their tails back­wards, pro­pelling them back into the safety of its ten­ta­cles. ("The of­fi­cial site for Thor am­bione­sis", 2010; "Thor am­boinen­sis", 2009; Baeza and Piantoni, 2010)

• Anti-predator Adaptations
• cryptic

• Known Predators

  • Triggerfish (Balistidae sp.)
  • Hawkfish (Cirrhitidae sp.)
  • Wrasse (Halichoeres sp.)
  • Angelfish (Pomacanthidae sp.)
  • Broadbarred firefish (Pterois antennata)
  • Harlequin bass (Serranum tigrinus)

Ecosys­tem Roles

Sexy shrimp have a com­men­sal re­la­tion­ships with a large va­ri­ety of anemones (as these shrimp are gen­er­al­ists, the list below is by no means a com­plete rep­re­sen­ta­tion of their hosts); they keep the anemones clean from mucus while the anemones pro­vide pro­tec­tion to the shrimp. Sexy shrimp may also found on rocks and corals, as well as other an­i­mals (in­clud­ing Ri­cordea and Crinoidea sp.). Sexy shrimp have been ob­served clean­ing man­tis shrimp (Ly­siosquil­lina lisa), pick­ing par­a­sites off of their cara­paces, al­though this ac­tiv­ity is not con­sid­ered a pri­mary mode of feed­ing or be­hav­ior for this species. These shrimp may be in­fected with iso­pod par­a­sites. ("The of­fi­cial site for Thor am­bione­sis", 2010; "Thor am­boinen­sis", 2009; Baeza and Piantoni, 2010; Cri­ales, 1984; Guo, et al., 1996; Khan, et al., 2004; Wirtz, 1997)

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Sexy shrimp are pop­u­lar in home aquaria due to their ap­pear­ance and rel­a­tively easy main­te­nance. Also, they are use­ful to re­searchers in study­ing their nat­ural his­tory and sex­ual sys­tems, as well as the im­por­tance of en­vi­ron­men­tal con­di­tions in ex­plain­ing the evo­lu­tion of sex de­ter­mi­na­tion in crus­taceans. ("The of­fi­cial site for Thor am­bione­sis", 2010; "Thor am­boinen­sis", 2009; Baeza and Piantoni, 2010)

• Positive Impacts
• pet trade
• research and education

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

There are no known ad­verse af­fects of this species on hu­mans.

Con­ser­va­tion Sta­tus

This species has not been eval­u­ated by the IUCN, nor is it cur­rently con­sid­ered threat­ened or en­dan­gered by any agency. ("In­ter­na­tional Union for the Con­ser­va­tion of Na­ture and Nat­ural Re­sources", 2013)

• IUCN Red List

  Not Evaluated

• US Federal List

  No special status

• CITES

  No special status

• State of Michigan List

  No special status

Con­trib­u­tors

Seona Choi (au­thor), Uni­ver­sity of Michi­gan-Ann Arbor, Renee Mul­crone (ed­i­tor), Spe­cial Pro­jects, Je­remy Wright (ed­i­tor), Uni­ver­sity of Michi­gan-Ann Arbor.

Ref­er­ences

2011. "Breed­ing Jour­nal: Species Thor am­boinen­sis" (On-line). Ma­rine Breed­ing Ini­tia­tive. Ac­cessed Feb­ru­ary 02, 2012 at http://​www.​mbisite.​org/​Forums/​tm.​aspx?​m=50570&​mpage=1.

ITIS. Com­mon and Sci­en­tific Names of Aquatic In­ver­te­brates from the United States and Canada: De­ca­pod Crus­taceans. TSN 96920. Bethesda, Mary­land, USA: Amer­i­can Fish­eries So­ci­ety. 2005. Ac­cessed Feb­ru­ary 02, 2012 at http://​www.​itis.​gov/​servlet/​SingleRpt/​SingleRpt?​search_​topic=TSN&​search_​value=96920.

2013. "In­ter­na­tional Union for the Con­ser­va­tion of Na­ture and Nat­ural Re­sources" (On-line). Ac­cessed Au­gust 09, 2013 at http://​www.​iucnredlist.​org/​search.

2010. "The of­fi­cial site for Thor am­bione­sis" (On-line). Ac­cessed Feb­ru­ary 02, 2012 at http://​sexyshrimp.​com/​.

2009. "Thor am­boinen­sis" (On-line). Trop­i­cal Fish Hob­by­ist Mag­a­zine. Ac­cessed Feb­ru­ary 02, 2012 at http://​www.​tfhmagazine.​com/​details/​marine-invert/​thor-amboinensis.​htm.

Baeza, J., C. Piantoni. 2010. Sex­ual sys­tem, sex ratio, and group liv­ing in the shrimp Thor am­boinen­sis (De Man): Rel­e­vance to re­source-mo­nop­o­liza­tion and sex-al­lo­ca­tion the­o­ries. Bi­o­log­i­cal Bul­letin, 219/2: 151-65. Ac­cessed Feb­ru­ary 02, 2012 at http://​www.​ncbi.​nlm.​nih.​gov/​pubmed/​20972260.

Bauer, R. 2001. Chem­i­cal com­mu­ni­ca­tion in de­ca­pod shrimps: The in­flu­ence of mat­ing and so­cial sys­tems on the rel­a­tive im­por­tance of ol­fac­tory and con­tact pheromones. Pp. 277-296 in T Bre­i­thaupt, M Thiel, eds. Chem­i­cal Com­mu­ni­ca­tion in Crus­taceans. New York, New York: Springer Sci­ence + Busi­ness Media. Ac­cessed Au­gust 05, 2013 at http://​decapoda.​nhm.​org/​pdfs/​32344/​32344.​pdf.

Cal­ado, R., L. Nar­ciso, R. Araújo, J. Lin. 2003. Overview of ma­rine or­na­men­tal shrimp aqua­cul­ture. Pp. 221-232 in J Cato, C Brown, eds. Ma­rine Or­na­men­tal Species: Col­lec­tion, Cul­ture & Con­ser­va­tion. Iowa City, Iowa: Iowa State Press. Ac­cessed Feb­ru­ary 02, 2012 at http://​onlinelibrary.​wiley.​com/​doi/​10.​1002/​9780470752722.​ch15/​summary.

Cri­ales, M. 1984. Shrimps as­so­ci­ated with coe­len­ter­ates, echin­o­derms, and mol­luscs in the Santa Marta Re­gion, Colom­bia. Jour­nal of Crus­tacean Bi­ol­ogy, 4/2: 307-317. Ac­cessed Feb­ru­ary 02, 2012 at http://​decapoda.​nhm.​org/​pdfs/​25253/​25253.​pdf.

De Grave, S. 2007. Notes on some shrimp species (De­capoda : Caridea) from the Per­sian Gulf. An­nalen des Naturhis­torischen Mu­se­ums in Wien. Serie B für Botanik und Zo­olo­gie, 108: 145-152. Ac­cessed Feb­ru­ary 23, 2012 at http://​www.​landesmuseum.​at/​pdf_​frei_​remote/​ANNA_​108B_​0145-0152.​pdf.

De­Grave, S., C. Fransen, M. Türkay. 2013. "Thor am­boinen­sis" (On-line). World Reg­is­ter of Ma­rine Species. Ac­cessed Au­gust 07, 2013 at http://​www.​marinespecies.​org/​aphia.​php?​p=taxdetails&​id=107534.

Guo, C., J. Hwang, D. Fautin. 1996. Host se­lec­tion by shrimps sym­bi­otic with sea anenomes: a field sur­vey and ex­per­i­men­tal lab­o­ra­tory analy­sis. Jour­nal of Ex­per­i­men­tal Ma­rine Bi­ol­ogy and Ecol­ogy, 202: 165-176. Ac­cessed Au­gust 07, 2013 at http://​web.​nhm.​ku.​edu/​inverts/​pdf/​Guo_​Hwang_​Fautin_​1996.​pdf.

Khan, R., J. Becker, A. Crowther, I. Lawn. 2004. Spa­tial dis­tri­b­u­tion of sym­bi­otic shrimps (Per­i­climenes holthuisi, P. bre­vi­carpalis, Thor am­boinen­sis) on the sea anemone Sti­chodactyla had­doni. Jour­nal of the Ma­rine Bi­o­log­i­cal As­so­ci­a­tion of the UK, 84/1: 201-203. Ac­cessed Feb­ru­ary 02, 2012 at http://​journals.​cambridge.​org/​action/​displayAbstract?​fromPage=online&​aid=201707.

Michael, S. 2012. "Anemone Shrimp" (On-line). Fishchan­nel. Ac­cessed April 06, 2012 at http://​www.​fishchannel.​com/​media/​saltwater-aquariums/​species-info/​invertebrates/​anemone-shrimp.​aspx.​pdf.

Sarver, D. 1979. Lar­val cul­ture of the shrimp Thor am­boinen­sis (De Man, 1888) with ref­er­ence to its sym­bio­sis with the anemone An­theop­sis pa­pil­losa (Kwiet­niewski, 1898). Crus­taceana Sup­ple­ment, 5: 176-178. Ac­cessed Feb­ru­ary 02, 2012 at http://​www.​jstor.​org/​stable/​25027500.

Wirtz, P. 1997. Crus­tacean sym­bionts of the sea anemone Tel­mat­ac­tis cricoides at Madeira and the Ca­nary Is­lands. Jour­nal of Zo­ol­ogy, 242/4: 799-811. Ac­cessed Feb­ru­ary 24, 2012 at http://​onlinelibrary.​wiley.​com/​doi/​10.​1111/​j.​1469-7998.​1997.​tb05827.​x/​pdf.