Animal Diversity Web

Ge­o­graphic Range

Pseudo­biceros bed­fordi, the Per­sian car­pet flat­worm, has a very small ge­o­graphic range mostly in the tem­per­ate shal­low in­ter­tidal ocean wa­ters of the Indo-West Pa­cific. They are rarely seen but most re­ports have re­ported sight­ings on the Great Bar­rier Reef, the coast of Guam, Papua New Guinea, In­done­sia, and Aus­tralia. The species is often men­tioned as a scuba div­ing spec­ta­cle on tourism web­sites for Sin­ga­pore. (New­man, et al., 2003; New­man and Can­non, 1997; Sei­farth, 2002)

• Biogeographic Regions
• oriental
  • native
• australian
  • native

Habi­tat

The habi­tat for Pseudo­biceros bed­fordi is mainly ben­thic and found in shal­low ma­rine habi­tats among rocks and crevices in a bay, la­goon or on a reef. The flat­worms are most likely to be found under rub­ble at a reef crest or at the ledges of a reef slope. They are adapted for swim­ming but the ma­jor­ity of the time are safely hid­den among rocks or other hard sub­strates such as reefs. These flat­worms are able to swim freely by swift, flam­boy­ant un­du­la­tions of their ruf­fled perime­ter. There­fore, al­though they pre­fer the safety of a sub­strate, it is pos­si­ble to spot them through­out the water col­umn. (New­man, et al., 2003; New­man and Can­non, 1997; Sei­farth, 2002)

• Habitat Regions
• saltwater or marine

• Aquatic Biomes
• reef
• coastal

• Other Habitat Features
• intertidal or littoral

• Average depth

  11 m

  36.09 ft

Phys­i­cal De­scrip­tion

The size of P. bed­fordi ranges from 8-10 cen­time­ters. These flat­worms are very del­i­cate crea­tures, hav­ing thin rib­bon-like elon­gated or oval-shaped bod­ies ap­prox­i­mately a mil­lime­ter thick with a thicker mid­line. They have a very flat and smooth dor­sal sur­face and are only a few mil­lime­ters thick. The Per­sian car­pet flat­worms are often mis­taken for a nudi­branch due to their bright col­ors, but the flat­worms are flat­ter and move quicker. The body has rich pat­terns of stripes in black, brown and rose pink with tiny white dots. The stripes curve from the cen­ter of the body to the sides and the edge of the body is black with white dots, usu­ally highly ruf­fled. The ruf­fled edges are used for swim­ming.

Promi­nent pseudo­ten­ta­cles are formed by sim­ple folds of the an­te­rior mar­gin. Dif­fer­ent from nudi­branchs, they do not have ex­ter­nal gills or lungs, in­stead they can ex­change gas across their en­tire body sur­face, through dif­fu­sion. A slightly ruf­fled phar­ynx is lo­cated in the an­te­rior one-third of the body and the mouth is a large open­ing lo­cated at the an­te­rior end of the phar­ynx. The sucker is con­spic­u­ous and cen­trally lo­cated. The ven­tral sur­face is a light pink and when "penis fenc­ing" they pro­trude the dou­ble pronged stylet from the ven­tral sur­face. They have two male pores and one fe­male pore, how­ever, the fe­male pore is not the point of in­ser­tion for in­sem­i­na­tion be­cause in­sem­i­na­tion can take place on any part of the sur­face of the flat­worm. (New­man, et al., 2003; Michielis, 2006; New­man and Can­non, 1997; Sei­farth, 2002; Tan, 2008)

• Other Physical Features
• ectothermic
• heterothermic
• bilateral symmetry
• poisonous

• Sexual Dimorphism
• sexes alike

• Average length

  2-6 cm

  in

De­vel­op­ment

The de­vel­op­ment of this species is not known but it is be­lieved that like most flat­worms they un­dergo meta­mor­pho­sis. After ten days of de­vel­op­ment, the larva hatch and are lobed and with cilia. The larva then enter the plank­tonic phase and swim around for a few days be­fore set­tling onto a place with a suf­fi­cient source of food; there, they meta­mor­phose into adult ben­thic forms. (Michielis, 2006; Sei­farth, 2002)

• Development - Life Cycle
• metamorphosis

Re­pro­duc­tion

Pseudo­biceros bed­fordi is her­maph­ro­ditic pro­duc­ing both eggs and sperm. The ma­jor­ity of their body vol­ume is made of testes and ovaries. Pseudo­ten­ta­cles help gather chemosen­sory in­for­ma­tion to find a mat­ing parter. When a mat­ing part­ner is found, the two her­maph­ro­dites have a dual or "penis fence" to see who bears the bur­den of moth­er­hood which is much more en­ergy costly. The two worms will dance and at­tempt to stab one an­other with their dou­ble-prong penis stylet. When the thin tis­sue of the loser is stabbed, it is im­me­di­ately in­sem­i­nated and the loser re­treats to bear the bur­den of moth­er­hood. (New­man, et al., 2003; Garfield, 2010; Michielis, 2006; Sei­farth, 2002)

In poly­clad worms, eggs are fer­til­ized as they meet sperm and pass down the oviducts. While still in­side the flat­worm, a pro­tec­tive shell or cap­sule is formed around the eggs. The cap­sule sur­round­ing the egg is hard­ened when re­leased by the worm into the sur­round­ing en­vi­ron­ment. Poly­clad eggs are usu­ally laid in thin sheets with sticky se­cre­tions. (New­man, et al., 2003)

• Key Reproductive Features
• simultaneous hermaphrodite
• fertilization
  • internal
• oviparous

• Breeding interval

  The breeding interval is not known.

• Breeding season

  The breeding season is not known.

• Average number of offspring

  a few hundred

• Average gestation period

  10 days

While no parental care is pro­vided after the worms lay their eggs, a pro­tec­tive cap­sule sur­round­ing the egg is se­creted prior to the worm's re­lease of the eggs. (New­man, et al., 2003)

• Parental Investment
• pre-hatching/birth
  • protecting
    • female

Lifes­pan/Longevity

Larva in lab con­di­tions sur­vived for only two weeks. This species is dif­fi­cult to keep alive in cap­tiv­ity. (Sei­farth, 2002)

• Range lifespan
  Status: captivity

  14 (high) days

Be­hav­ior

When stressed the flat­worm will dis­solve in its own en­zymes. Be­cause Pseudo­biceros bed­fordi is her­maph­ro­ditic, it is as­sumed that part­ners rarely en­counter one an­other re­sult­ing in a soli­tary lifestyle. How­ever, when they do en­counter ea­chother, they per­form a mat­ing be­hav­ior called "penis fenc­ing". (Garfield, 2010; Sei­farth, 2002)

• Key Behaviors
• natatorial
• nocturnal
• solitary

Com­mu­ni­ca­tion and Per­cep­tion

Com­mu­ni­ca­tion and per­cep­tion of Pseudo­biceros bed­fordi is like other poly­clad flat­worms. On the head are pseudo­ten­ta­cles with sev­eral pho­to­sen­si­tive and chemosen­si­tive cells. These cells send in­for­ma­tion to the an­te­rior cere­br­ial gan­glion knot lo­cated on the dor­sal an­te­rior area or "head". Also, dis­persed through­out the epi­der­mis are mechanore­cep­tors that re­spond to pres­sure. Pho­to­sen­si­tive cells can be found on the cere­bral eye­spot where nu­mer­ous eyes (about 90–100) ap­pear to form round clus­ters. Fur­ther eyes are lo­cated on the ven­tral and dor­sal pseudo­ten­ta­cles. These eyes are sen­si­tive to changes in light di­rec­tion and in­ten­sity and form im­ages ac­cord­ing to shad­ows pro­duced from sur­round­ings. They sense their sur­round­ings by changes in shadow pat­tern. Since these crea­tures are mostly noc­tur­nal, when they sense bright light they usu­ally re­treat to a darker place such as a rock crevice. Since the flat­worm has weak vi­sual senses, it re­lies mostly on chemosen­sory de­tec­tors. Chemore­cep­tors on the pseudo­ten­ta­cles are thought be re­spon­si­ble for sens­ing food as well as mat­ing part­ners. Spe­cific chem­i­cals that are re­leased from food or mat­ing part­ners float through the water and are then sensed by the worms chemore­cep­tors on their pseudote­na­cles. In ad­di­tion to their au­ri­cles and eye­spots, flat­worms have prim­i­tive bal­ance or­gans called sta­to­cysts, which con­sist of pres­sure sen­si­tive hairs and small grains of ma­te­r­ial that can roll around to tell the flat­worm which way is up. (New­man, et al., 2003; New­man and Can­non, 1997; Sei­farth, 2002)

• Communication Channels
• chemical

• Perception Channels
• polarized light
• tactile
• chemical

Food Habits

Pseudo­biceros bed­fordi preys mainly on as­cid­i­ans as well as small crus­taceans. They feed like a starfish, glid­ing over the or­gan­ism and ex­trud­ing their phar­ynx that re­leases en­zymes. The en­zymes di­gest the tis­sue of their prey then suck the body liq­uids. Their prey in­cludes tiny an­i­mals such as pro­to­zoa and worms, ses­sile an­i­mals such as as­cid­i­ans and mol­luscs, and some have been ob­served eat­ing shrimps and crabs. (New­man, et al., 2003; Sei­farth, 2002; Tan, 2008)

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

• Animal Foods
• body fluids
• cnidarians
• other marine invertebrates

Pre­da­tion

• Anti-predator Adaptations
• aposematic

• Known Predators

  • Fish
  • Tailed slugs, Aglajidae

Ecosys­tem Roles

Lit­tle is known about the ecosys­tem role of this species.

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

There are no known pos­i­tive eco­nomic ef­fects of this species on hu­mans.

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

There are no known neg­a­tive eco­nomic ef­fects of this species on hu­mans.

Con­ser­va­tion Sta­tus

Pseudo­bis­ceros bed­fordi is not listed among the threat­ened an­i­mals. How­ever, they are very del­i­cate crea­tures and like other crea­tures of the in­ter­tidal zone, flat­worms are af­fected by human ac­tiv­i­ties such as recla­ma­tion and pol­lu­tion. Tram­pling by care­less vis­i­tors, and over­col­lec­tion of their food source can also have an im­pact on local pop­u­la­tions. (Tan, 2008)

• IUCN Red List

  Not Evaluated

• US Federal List

  No special status

• CITES

  No special status

• State of Michigan List

  No special status

Con­trib­u­tors

Amber Moryk­was (au­thor), Uni­ver­sity of Michi­gan-Ann Arbor, Renee Mul­crone (ed­i­tor), Spe­cial Pro­jects.

Ref­er­ences

Bolanos, M. 2007. Five new species of cotylean flat­worms (Platy­helminthes: Poly­cla­dida) from the wider Caribbean. Zootaxa, 1650: 1-23. Ac­cessed May 22, 2011 at http://​www.​mapress.​com/​zootaxa/​2007f/​zt01650p023.​pdf.

Garfield, J. 2010. "sdnews.​com" (On-line). Ac­cessed May 22, 2011 at http://​www.​sdnews.​com/​view/​full_​story/​4479639/​article-For-polyclad-worm--sex-and-swordplay-synonymous?​instance=LJ_​home_​news_​bullets.

Michielis, N. 2006. "Bat­tle of the her­maph­ro­dites" (On-line). Ac­cessed May 22, 2011 at http://​www.​biologyjunction.​com/​hermaphrodite_​article.​htm.

New­man, L., L. Can­non. 1996. Bu­laceros, new genus, and Tyt­thosoceros, new genus, from the Great Bar­rier Reef, Aus­tralia and Papua New Guinea. The Raf­fles Bul­letin of Zo­ol­ogy, 44/2: 479-492. Ac­cessed May 22, 2011 at http://​rmbr.​nus.​edu.​sg/​rbz/​biblio/​44/​44rbz479-492.​pdf.

New­man, L., L. Can­non. 1997. Nine new species of Pseudo­biceros from the Indo-Pa­cific. The Raf­fles Bul­letin of Zo­ol­ogy, 45/2: 341-368. Ac­cessed May 22, 2011 at http://​rmbr.​nus.​edu.​sg/​rbz/​biblio/​45/​45rbz341-368.​pdf.

New­man, L., L. Can­non, A. Flow­ers. 2003. Ma­rine flat­worms: the world of poly­clads. Colling­wood, Aus­tralia: CSIRO Pub­lish­ing. Ac­cessed May 22, 2011 at http://​books.​google.​com/​books?​id=pwLs5AD_​C-cC&​printsec=frontcover&​source=gbs_​v2_​summary_​r&​cad=0#​v=onepage&​q=&​f=false.

Rawl­in­son, K. 2008. Bio­di­ver­sity of coastal poly­clad flat­worm as­sem­blages in the wider Caribbean. Ma­rine Bi­ol­ogy, 153: 769-778. Ac­cessed May 22, 2011 at http://​www.​springerlink.​com/​content/​t25n0553873323m4/​.

Rit­son-Williams, R. 2003. Check­list of poly­clad flat­worms (Platy­helminthes) from Mi­crone­sian coral reefs. Mi­cronesica, 2003/35-36: 189-199. Ac­cessed May 22, 2011 at http://​university.​uog.​edu/​up/​micronesica/​abstracts_​35-36/​pdfs_​3536/​10-flatworms.​pdf.

Sei­farth, W. 2002. "Ma­rine flat­worms of the world - anatomy of poly­clad flat­worms" (On-line). Ac­cessed May 22, 2011 at http://​www.​rzuser.​uni-heidelberg.​de/​~bu6/flatintr.​htm#bio_­top.

Tan, R. 2008. "Per­sian car­pet worm" (On-line). Wild Fact Sheet. Ac­cessed May 22, 2011 at http://​www.​wildsingapore.​com/​wildfacts/​worm/​polycladida/​bedfordi.​htm.