Phylum Kamptozoa) includes nearly 200 currently known species of sessile, solitary (family Loxosomatidae) or colonial (families Loxokalypodidae, Pedicellinidae and Barentsiidae), primarily marine organisms, although two freshwater species, Loxosomatoides sirindhorne and Urnatella gracilis have been identified. Marine species are found throughout the world’s oceans, and Urnatella gracilis is found on all continents except Antarctica. These organisms superficially resemble cnidarian hydroids and bryozoans (Phylum Bryozoa); the main body consists of a cup-like calyx that bears a ring of ciliated tentacles, which is attached on its dorsal surface to the substrate (or stolon in colonial species) by a long, thin stalk. Whether solitary or colonial, all entoprocts are sessile suspension feeders. Entoprocts exhibit a range of reproductive modes and behaviors, including asexual clonal reproduction, as well as hermaphroditic and dioecious sexual reproduction. (Appeltans, et al., 2012; Brusca and Brusca, 2003; Nielsen, 2002; Ruppert, et al., 2004; Schwaha, et al., 2010; Zhang, 2011)(also known as
The majority of entoprocts live in coastal, marine environments throughout the world. Urnatella gracilis is found in rivers on every continent except Antarctica, and Loxosomatoides sirindhorne has been identified from rivers in Thailand. (Brusca and Brusca, 2003; Ramel, 2012; Schwaha, et al., 2010; Wood, 2005)
Following their discovery, these organisms were alternatively classified as special, polyp-like rotifers, or they were classified along with Bryozoa, in phylum Bryozoa. The name was first applied to these organisms by the German zoologist Hinrich Nitsche in 1870 to separate them from Bryozoa, based upon the position of the anus (inside the lophophore ring, rather than outside), embryonic cleavage pattern (spiral vs. radial), and differences in body cavity type (acoelomate vs. coelomate). These differences resulted in Hatschek elevating to phylum level in 1888. The name Kamptozoa would later be applied to this group by Carl Cori in 1929, and is still used interchangeably with . (Cori, 1929; Ellis, 1755; Hatschek, 1888; Nitsche, 1870; Pallas, 1774; Sars, 1835; van Beneden, 1845)
The monophyly of Solitaria and Coloniales, is well supported by morphological characters and a recent molecular phylogenetic analysis. However, the evolutionary relationships of entoprocts to other phyla remain a matter of some debate. Recent molecular phylogenetic studies have suggested that entoprocts and ectoprocts should in fact be considered classes within a single taxon called Polyzoa, in agreement with their original classification. These, and additional molecular studies have suggested that Polyzoa should also include the obscure phylum Cycliophora, which appears to share a sister relationship with . These studies also suggest that Polyzoa be placed in a larger superphylum, Lophotrochozoa, based on the common presence of the trochophore larval state in member phyla (which include annelid worms, mollusks, flatworms, and nemertean worms, among others). There is no consensus, however, on which of the lophotrochozoan phyla represent the closest relative of modern polyzoans. (Fuchs, et al., 2010; Funch and Kristensen, 1995; Giribet, et al., 2004; Hausdorf, et al., 2007; Hejnol, et al., 2009; Helmkampf, et al., 2008; Paps, et al., 2009a; Paps, et al., 2009b), as well as that of its two orders,
These organisms superficially resemble cnidarian hydroids and bryozoans (phylum Bryozoa), with the main body consisting of a cup-like calyx that bears a ring of 6 to 36 ciliated tentacles, attached on its dorsal surface to the substrate (or stolon in colonial species) by a long, thin stalk. The calyx and stalk are covered by a thin, collagenous cuticle, which does not extend over the tentacles, and is underlaid by a cellular epidermis. Muscle bands beneath the epidermis allow the organism to compress its calyx and stalk, extend its tentacles, and bend its stalk. These organisms are functionally acoelomate, lacking a fluid-filled body cavity. It is uncertain whether this condition results from a secondary filling of an embryonic blastocoel with mesenchyme, or whether these organisms lack a blastocoel throughout development. The viscera are located entirely in the calyx, with the mouth and anus found on the ventral surface (vestibule), surrounded by the tentacular crown. The gut is U-shaped and lined with a layer of ciliated cells, widening into a stomach near the internal base of the calyx, followed by an intestinal segment that leads to the anus. Entoprocts are quite small, with individual zooids ranging from 0.1 to 7 mm in length. (Brusca and Brusca, 2003; Ramel, 2012; Ruppert, et al., 2004)
Both colonial and solitary species are capable of asexual clonal reproduction by budding; species may reproduce sexually and be dioecious, simultaneous, or protandrous hermaphrodites. Eggs either hatch into planktonic larvae, or in some species, complete early development in a brood chamber (located in the atrium), attached by secretions of cement glands to the chamber's wall. In some brooding species, nutrition is provided to developing embryos via special placental cells; in others, the egg yolk nourishes the growing larvae. Planktonic larvae may remain free swimming for up to 7 months before settling, while those raised in a brood chamber will settle relatively quickly (within a few days of hatching). (Brusca and Brusca, 2003; Ruppert, et al., 2004; Shanks, 2001)
Entoproct embryonic development follows the holoblastic, spiral cleavage pattern typical of protostome organisms, with the mesoderm forming from the 4d mesentoblast. Development continues to a coeloblastula stage, after which, the embryos of most species proceed into a free swimming, feeding planktonic larval stage strongly resembling the trochophore larva of protostome species. Some species produce lecithotrophic or benthic crawling larvae. Trochophore larvae have equatorial ciliary bands (used for feeding on suspended particles), apical and ventral sensory tufts of cilia, pigment-cup ocelli that serve as light-sensing organs, a complete digestive system, and a pair of protonephridia for waste excretion. After their larval period, most entoprocts settle, attach to the substrate, and undergo metamorphosis. Unequal growth of the body directs the vestibular surface away from the substrate and the mouth, anus, and gut may rotate up to 180°, to face the vestibular surface; however, no rotation or unequal growth is necessary for some species. In these, an asexual bud forms from the attached larvae to form the zooid, which is already oriented in the correct position. (Brusca and Brusca, 2003; Nielsen, 2002)
Some species in family Loxosomatidae produce free swimming larvae that may produce adult buds precociously; the adults are held in a body pocket of the larvae until their release through the body wall, usually a few days. After release, the larvae die. In some species, adult buds have been noticed developing from larvae while the larvae were still developing in their parents' ovaries. In at least one species, males and females may be produced via budding. (Shanks, 2001)
Gonads, when present, are located just beneath the vestibular surface and empty into the water via the gonopore. Male zooids release sperm into the water, where it can be drawn into the reproductive tract of female zooids. Fertilization occurs in the ovaries or oviducts. (Brusca and Brusca, 2003)
Loxosomella antarctia is noted to regenerate the entire calyx in this way). It is possible to fold the tentacles and move the calyx using subepidermal musculature of the body and stalk. Once larvae have settled, they are most typically sessile, using a "foot" to attach to a substrate. A few species are reportedly capable of movement even after adulthood, for instance members of genus Loxasomella inside the tubes of marine annelids. (Brusca and Brusca, 2003; Emschermann, 1993; Margulis, et al., 1999; Ramel, 2012)may be colonial or solitary. An entoproct may shed (typically under adverse environmental conditions) and regenerate its calyx, sometimes changing sex when it does; most entoprocts with this ability are colonial (only one species of solitary entoproct,
Solitary sponges, annelids, sipunculans, ascidians, and ectoprocts. There is a high level of host specificity. Entoproct colonies may also be found on mollusk shells. There are no parasitic forms currently recognized and there is no data currently available regarding parasites of these animals. (Bleidorn, 2008; Brusca and Brusca, 2003; Emschermann, 1993; Kristensen, 1970; Weise, 1961; Wood, 2005)are most often commensal on invertebrates such as
A phoretic relationship has been identified between Urnatella gracilis and larval Cordalus cornutus (commonly called hellgrammites, the larval form of Eastern dobsonflies); as a result of this relationship, entoprocts gain a means of dispersal, protection from predators, and nutrition. (Tracy and Hazelwood, 1983)
Beyond the potential for scientific research, there are no known positive effects of (Brusca and Brusca, 2003)species on humans.
There is currently no concern regarding (Brusca and Brusca, 2003)species becoming threatened or endangered.
While rare, (Zhang, et al., 2013)fossils date back to approximately 520 million years ago, during the Cambrian period.
Jeremy Wright (author), University of Michigan-Ann Arbor, Leila Siciliano Martina (editor), Animal Diversity Web Staff.
Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.
living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
living in the southern part of the New World. In other words, Central and South America.
living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.
reproduction that is not sexual; that is, reproduction that does not include recombining the genotypes of two parents
Referring to an animal that lives on or near the bottom of a body of water. Also an aquatic biome consisting of the ocean bottom below the pelagic and coastal zones. Bottom habitats in the very deepest oceans (below 9000 m) are sometimes referred to as the abyssal zone. see also oceanic vent.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
areas with salty water, usually in coastal marshes and estuaries.
the nearshore aquatic habitats near a coast, or shoreline.
used loosely to describe any group of organisms living together or in close proximity to each other - for example nesting shorebirds that live in large colonies. More specifically refers to a group of organisms in which members act as specialized subunits (a continuous, modular society) - as in clonal organisms.
having a worldwide distribution. Found on all continents (except maybe Antarctica) and in all biogeographic provinces; or in all the major oceans (Atlantic, Indian, and Pacific.
active at dawn and dusk
union of egg and spermatozoan
mainly lives in water that is not salty.
having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.
a distribution that more or less circles the Arctic, so occurring in both the Nearctic and Palearctic biogeographic regions.
Found in northern North America and northern Europe or Asia.
fertilization takes place within the female's body
the area of shoreline influenced mainly by the tides, between the highest and lowest reaches of the tide. An aquatic habitat.
A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
active during the night
found in the oriental region of the world. In other words, India and southeast Asia.
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
an animal that mainly eats plankton
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
condition of hermaphroditic animals (and plants) in which the male organs and their products appear before the female organs and their products
structure produced by the calcium carbonate skeletons of coral polyps (Class Anthozoa). Coral reefs are found in warm, shallow oceans with low nutrient availability. They form the basis for rich communities of other invertebrates, plants, fish, and protists. The polyps live only on the reef surface. Because they depend on symbiotic photosynthetic algae, zooxanthellae, they cannot live where light does not penetrate.
mainly lives in oceans, seas, or other bodies of salt water.
breeding is confined to a particular season
remains in the same area
non-motile; permanently attached at the base.
Attached to substratum and moving little or not at all. Synapomorphy of the Anthozoa
reproduction that includes combining the genetic contribution of two individuals, a male and a female
uses touch to communicate
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
breeding takes place throughout the year
Appeltans, W., P. Bouchet, G. Boxshall, C. De Broyer, N. de Voogd, D. Gordon, B. Hoeksema, T. Horton, M. Kennedy, J. Mees, G. Poore, G. Read, S. Stöhr, T. Walter, M. Costello. 2012. "WoRMS - World Registry of Marine Species" (On-line). Accessed February 23, 2013 at http://www.marinespecies.org/.
Bleidorn, C. 2008. Lophotrochozoan relationships and parasites. A snap-shot. Parasite, 15/3: 329-332. Accessed May 02, 2013 at http://www.parasite-journal.org/index.php?option=com_article&access=doi&doi=10.1051/parasite/2008153329&Itemid=129.
Brusca, R., G. Brusca. 2003. Invertebrates (2nd Edition). Sunderland MA: Sinauer Associates.
Canning, M., J. Carlton. 2000. Predation on kamptozoans (Entoprocta). Invertebrate Biology, 119/3: 386-387.
Cori, C. 1929. Kamptozoa. Pp. 1-64 in W Kukenthal, T Krumbach, eds. Handbuch der Zoologie: Eine Naturgeschichte der Stamme des Tierreiche, Vol. 2/5. Berlin, Germany: Walter de Gruyter and Co.
Ellis, J. 1755. An essay towards a natural history of the corallines, and other marine productions of the like kind, commonly found on the coasts of Great Britain and Ireland. To which is added the description of a large marine polype taken near the North Pole, by the whale-fishers, in the summer 1753. London, UK: John Ellis.
Emschermann, P. 1985. Factors inducing sexual maturation and influencing the sex determination of Barentsia discreta Busk ( , Barentsiidae). Pp. 101-108 in C Nielsen, G Larwood, eds. Bryozoa: Ordovician to Recent. Fredensborg, Denmark: Olsen and Olsen. Accessed May 01, 2013 at http://books.google.com/books?hl=en&lr=&id=MdcupzBwiCgC&oi=fnd&pg=PA101&dq=entoprocta+life+span&ots=kKL6LtlYVk&sig=hCqgzJaY93fmOUBgdh7KYNctKdY#v=onepage&q&f=false.
Emschermann, P. 1993. On Antarctic Biological Bulletin, 184: 153-185. Accessed May 01, 2013 at http://www.biolbull.org/content/184/2/153.full.pdf.: nematocyst-like organs in a Loxosomatid, adaptive developmental strategies, host specificity, and bipolar occurrence of species.
Fuchs, J., T. Iseto, M. Hirose, P. Sundberg, M. Obst. 2010. The first internal molecular phylogeny of the animal phylum Kamptozoa). Molecular Phylogenetics and Evolution, 56: 370-379.(
Giribet, G., M. Sorensen, P. Funch, R. Kristensen, W. Sterrer. 2004. Investigations into the phylogenetic position of Micrognathozoa using four molecular loci. Cladistics, 20: 1-13.
Hatschek, B. 1888. Lehrbuch der Zoologie. Jena, Germany: Fischer.
Hausdorf, B., M. Helmkampf, A. Meyer, A. Witek, H. Herlyn, I. Bruchhaus, T. Hankeln, T. Struck, B. Lieb. 2007. Spiralian phylogenomics supports the resurrection of Bryozoa comprising Bryozoa and . Molecular Biology and Evolution, 24/12: 2723-2729.
Hejnol, A., M. Obst, A. Stamatakis, M. Ott, G. Rouse, G. Edgecombe, P. Martinez, J. Baguñà, X. Bailly, U. Jondelius, M. Wiens, W. Müller, E. Seaver, W. Wheeler, M. Martindale, G. Giribet, C. Dunn. 2009. Assessing the root of bilaterian animals with scalable phylogenomic methods. Proceedings of the Royal Society B-Biological Sciences, 276: 4261-4270.
Helmkampf, M., I. Bruchhaus, B. Hausdorf. 2008. Phylogenomic analyses of lophophorates (brachiopods, phoronids, and bryozoans) confirm the Lophotrochozoa concept. Proceedings of the Royal Society B: Biological Sciences, 275: 1927-1933.
Kristensen, J. 1970. Fauna associated with the sipunculid Phascolion strombi (Montagu), especially the parasitic gastropod Menestho diaphana (Jeffreys). Ophelia, 7/2: 257-276. Accessed May 02, 2013 at http://www.tandfonline.com/doi/abs/10.1080/00785236.1970.10419300#preview.
Margulis, L., K. Schwartz, M. Dolan. 1999. Diversity of Life: The Illustrated Guide to the Five Kingdoms. Sudbury, MA: Jones and Bartlett Publishers.
Nielsen, C. 2001. Animal Evolution. Interrelationships of the Living Phyla, second edition. U.K.: Oxford University Press.
Nielsen, C. 2002. "http://onlinelibrary.wiley.com/doi/10.1038/npg.els.0001596/full." (On-line). Encyclopedia of Life. Accessed April 30, 2013 at
Nitsche, H. 1870. Beobachtungen über die Entwicklungsgeschichte einiger chilostomen Bryozoen. Zeitschrift für Wissenschaftliche Zoologie, 20: 1-37.
Pallas, P. 1774. Spicilegia Zoologica. Quibus novae imprimis et obscurae animalium species, vol. 1. Berlin, Germany: G.A. Lange.
Paps, J., J. Baguñà, M. Riutort. 2009. Bilaterian phylogeny: a broad sampling of 13 nuclear genes provides a new lophotrochozoan phylogeny and supports a paraphyletic basal Acoelomorpha. Molecular Biology and Evolution, 26: 2397-2406.
Paps, J., J. Baguñà, M. Riutort. 2009. Lophotrochozoa internal phylogeny: new insights from an up-to-date analysis of nuclear ribosomal genes. Proceedings of the Royal Society B-Biological Sciences, 276: 1245-1254.
Ramel, G. 2012. "The Goblet Worms (Phylum http://www.earthlife.net/inverts/entoprocta.html.)" (On-line). Earthlife. Accessed April 30, 2013 at
Ruppert, E., R. Fox, R. Barnes. 2004. Invertebrate Zoology: A functional evolutionary approach (7th Edition). Belmont, CA: Thomson-Brooks/Cole.
Sars, M. 1835. Beskrivelser og iagtagelser over nogle maerkelige eller nye I havet ved den Bergenske Kyst levende dyr af Polypernes, Acalephernes, Radiaternes, Annelidernes og Molluskernes Classer. Bergen, Norway: T. Hallager.
Schwaha, T., T. Wood, A. Wanninger. 2010. Trapped in freshwater: the internal anatomy of the entoproct Loxosomatoides sirindhornae. Frontiers in Zoology, 7: 7. Accessed April 30, 2013 at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2826350/.
Shanks, A. 2001. Entoprocta. Pp. 37-38 in A Shanks, ed. Identification Guide to Larval Marine Invertebrates of the Pacific Northwest. Corvallis, OR: University of Oregon Press. Accessed May 01, 2013 at https://scholarsbank.uoregon.edu/xmlui/bitstream/handle/1794/6123/5.pdf?sequence=17.
Soule, D., J. Soule. 1968. Bryozoan fouling organisms from Oahu, Hawaii, with a new species of Watersipora. Bulletin of the Southern California Academy of Sciences, 67/4: 203-218. Accessed May 02, 2013 at http://biostor.org/reference/100030.text.
Tracy, B., D. Hazelwood. 1983. The phoretic association of Urnatella gracilis ( : Urnatellidae) and Nanocladius downesi (Diptera: Chironomidae) on Corydalus cornutus (Megaloptera: Corydalidae). Freshwater Invertebrate Biology, 2/4: 186-191. Accessed May 02, 2013 at http://www.jstor.org/stable/1467150.
Winston, J. 1982. Marine bryozoans (Bryozoa) of the Indian River area (Florida). Bulletin of the American Museum of Natural History, 173: 102-169. Accessed May 01, 2013 at http://digitallibrary.amnh.org/dspace/handle/2246/439.
Wood, T. 2005. Loxosomatoides sirindhornae, new species, a freshwater kamptozoan from Thailand ( ). Hydrobiologia, 544: 27-31.
Wood, T., P. Anurakpongsatorn, J. Mahujchariyawong. 2006. Freshwater Bryozoans of Thailand (Bryozoa and ). The Natural History Journal of Chulalongkorn University, 6/2: 83-119. Accessed May 02, 2013 at http://www.wright.edu/~tim.wood/documents/2006_ThaiBryos_000.pdf.
Zhang, Z. 2011. Animal biodiversity: an introduction to higher-level classification and taxonomic richness. Zootaxa, 3148: 7-12.
Zhang, Z., L. Holmer, C. Skovsted, G. Brock, G. Budd, D. Fu, X. Zhang, D. Shu, J. Han, J. Liu, H. Wang, A. Butler, G. Li. 2013. A sclerite-bearing stem group entoproct from the early Cambrian and its implications. Scientific Reports, 3/1066: 1-7.
van Beneden, P. 1845. Recherches sur l'anatomie, la physiologie et le développement des Bryozoaires qui habitent la côte d'Ostendc. Histoire naturelle du genre Pedicellina. Nouveaux Mémoires de l'Académie Royale des Sciences et des Belles-Lettres de Bruxelles, 19: 1-31.