• Hydra is a solitary species and lives attached to substrates, whereas Obelia is a colonial species and lives as polyps in an interconnected branching network. Hydrozoa have a variety of life cycles. Most hydrozoans alternate between a polyp and a medusa stage — they spend part of their lives as "jellyfish" which are hard to distinguish from scyphozoan jellyfish. A great many hydrozoans are also colonial. Polyps and Medusae are the names of two body forms. Fixed, rarely free, found near water mark attached to rocks. Examine the live specimens of Hydra fuscus (brown hydra) and Hydra viridens (green hydra has symbiotic algae). However, Hydra is not typical of the Hydrozoa as a whole. Genus Hydra. The polyp may be solitary, as in the sea anemone, or colonial, as in coral, and is sessile (attached to a surface). Most hydras have a polyp and medusa stage. Some species of hydra can produce both ovary and testis. c. Look at the photo of the hydra (a small freshwater cnidarian, bottom left photo). This is the beginning of the rest of the animal kingdom, the eumetazoa, or "true animals" (we eumetazoans are a little biased). That's radi… The two forms are similar in construction; both consist of a cylindrical body surrounding a digestive cavity, with a single opening, the mouth, at one end. The hydra can exist in its adult and sexual form which is... Our experts can answer your tough homework and study questions. Sciences, Culinary Arts and Personal • Hydra live in freshwater habitats, whereas Obelia is exclusively marine. Medusa and polyp are the two body forms of cnidarians that alter through generations. answered • 07/26/16. Hydras are sessile animals, but the polyps are able to move and change their location. Hydra) are single; others (e.g. 0 0. There are many differences between medusae and polyps with regard to the shapes, sizes, and functions. Where only the polyp exists, as in the hydra and the sea anemone, the organism has the ability to produce new polyps sexually, as well as by budding. Hydra never goes through a medusoid stage and spends its entire life as a polyp. The medusa, when free swimming, is popularly known … Hydra does not have a medusa form and reproduces sexually by the formation of gametes. Also, the dominant phase of the life cycle of Obelia is the polyp. They have a simple body consisting of a central gut cavity surrounded by tentacles. Polyp, in zoology, one of two principal body forms occurring in members of the animal phylum Cnidaria. Phylum Cnidaria, which include about 9000 species is also commonly called Coelenterata. The hydra can exist in its adult and sexual form which is... See full answer below. It is present in both the freshwater and marine water habitat. Other creatures start life as fee-swimming medusa, then settle and become polyps. Genus Hydra. The stinging animals are more complex than the . Coelenterata is a Greek word named for a group of animals that possess a single large central cavity coelenteron (comes from the Greek "koilos"- hollow; "enteron" - intestine or gastrovascular cavity with a single opening that serves both as a mouth and as anus. Some have no polyp stages and some (e.g. Explain Polyp and Medusa bodyforms give examples to support the answer. Simply, the modes of living are different between a medusa and a polyp. Body cylindrical with a long stalk (Hydra). Polyps typically reproduce asexually by budding to form either new polyps or medusae. They have a simple body consisting of a central gut cavity surrounded by tentacles. Obelia’s sexual stage is medusa. If not then please post again and I shall try to explain. There can be variations in the structure but the similarity in shape is the presence of tentacular structure and the outer structure. Smith. Medusa is the adult and sexual form whereas Polyp is juvenile and asexual form. This polyp is also called “scyphistoma”. Medusa is a type of body form found in cnidarians. However, Hydra is not typical of the Hydrozoa as a whole. Polyp a medusa jsou dva typy tělesných forem identifikovaných v Cnidarians. It usually reproduces asexually only in the medusa form by the formation of gametes. Hydra can exist in both forms namely a polyp and a medusa throughout their life cycle. 8 years ago. • Unlike Obelia, Hydra has great regenerative powers. Fylum: Cnidaria se skládá ze čtyř tříd: Hydrozoa (Hydra, siphonophores), Scyphozoa (medúza), Cubozoa (krabicové želé) a Anthozoa (sasanky, korály, mořská pera).Anthozoa je přisedlý. Polyp and medusa body shapes Next. In the phylum Cnidaria, which includes jellyfish and sea anemones, polyp and medusa are two different stages of the life cycle. Some polyps (e.g. Body attached below so that manubrium is … Medusa. Corals, sea anemones and jellyfish belong to a group of animals called cnidarians. Life cycle: Cnidarians alternate between the polyp and medusa life forms. answer! Hydra (class specimen) has no POLYP form. hydra) have no medusae. The polyp may be solitary, as in the sea anemone, or colonial, as in coral, and is sessile (attached to a surface). Hydra can exist in both forms namely a polyp and a medusa throughout their life cycle. Hydra (genus) remains a polyp at all stages, but other hydrozoa do show both polyp and medusa stages in their life cycles. Most hydrozoans alternate between a polyp and a medusa stage — they spend part of their lives as "jellyfish" which are hard to distinguish from scyphozoan jellyfish. Body saucer shaped, umbrella like with a reduced stalk (Jellyfish). Josef Reischig, CSc. The polyp is a sessile, or nonmotile, organism; well-known solitary polyps are the sea anemone and the freshwater hydra. Jellyfish, on the other hand, exhibit only the medusa stage, while members of the genus Hydra exhibit the polyp form. In hydra, the medusa stage is absent and polyps reproduce both sexually and asexually. • Hydra does not have medusa form in their life cycle, whereas Obelia has both forms; polyp and medusa. © 2005 - 2021 Wyzant, Inc. - All Rights Reserved, a Question Polyp, in zoology, one of two principal body forms occurring in members of the animal phylum Cnidaria. Obelia is a form of hydrozoans that have branched stalks. It would appear, at first sight, that a medusa is entirely different from a hydranth, not only in form but also in minute structure. Earn Transferable Credit & Get your Degree. - Solitary and Colonial. Under harsh living conditions and starvation, hydra reproduces sexually. The medusa, when free swimming, is popularly known as a jellyfish. Like porifera, the hydra has two layers of cells separated by a jelly-like layer. Hydra exists in both forms: Polyp and Medusa. Naina B. 1. Jellyfish, on the other hand, exhibit only the medusa stage, while members of the genus Hydra exhibit the polyp form. Start here or give us a call: (312) 646-6365. Many other members of the class Hydrozoa, however, change from a polyp … Other characteristics: Some animals of this group are always polyps, some are always medusae, and some exhibit both a polyp and a medusa stage in their life cycle. For Free, Your exam is tomorrow and you are expecting a miracle, Human neutrophil phagocytosing MRSA bacteria. If you think about the shape of a pumpkin, there's a top and a bottom, but no left, right, back, or front. RNDr. So it catches food from prey that swim past them. Medusae. Hydra exists in both forms: Polyp and Medusa. Hope this explains you the life-cycle. The mouth is surrounded by tentacles, which are used to capture food and convey it to the mouth; these tentacles are armed with stinging cells which paralyze the prey. These forms are dependent upon nutritional content of the living environment. All other trademarks and copyrights are the property of their respective owners. Some animals of this group are always polyps, some are always medusae, and some exhibit both a polyp and a medusa stage in their life cycle. All cnidarians only have one opening with functions for both ingestion and excretion. Two distinct body plans are found in Cnidarians: the polyp or tuliplike “stalk” form and the medusa or “bell” form. Unlike hydra, it usually occurs in two forms one is a polyp, and the second one is the medusa. Each polyp so affected loses under their influence its characteristic structure, and becomes trans formed by degrees into a medusa. Der Stamm: Cnidaria besteht aus vier Klassen: Hydrozoa (Hydra, Siphonophores), Scyphozoa (Quallen), Cubozoa (Kastengelees) und Anthozoa (Seeanemonen, Korallen, Seekugelschreiber).Anthozoa ist sessile. - examples of cnidarians exhibiting the polyp body form include freshwater hydra, as well as anemones, corals, and others - in many species, the polyps live in interconnected colonies (e.g., see discussion of stony coral structure below) the medusa body form - this … Eumetazoans have tissues that develop from the germ layers of the embryo, and there are two basic body styles that are defined by our symmetry, either radial or bilateral. A medusa is a specific condition of an organism where body is shaped like that of an umbrella. Hydras are up to 30 mm long solitary polyp animal, while Obelia is up to 25 cm long colony of interconnected polyps. 2. Like the difference between a pumpkin and a human head. Polyp have a tubular shape and are fixed at their base, with the mouth present at the other end of the tube facing the water. The polyp is a sessile, or nonmotile, organism; well-known solitary polyps are the sea anemone and the freshwater hydra. The polyp is a sessile, or nonmotile, organism; well-known solitary polyps are the sea anemone and the freshwater hydra. The upper, or free, end of the body, which is hollow and cylindrical, typically (CC BY-SA 3.0) Polyp: Medusa: Polyp is a sessile life cycle stage of the Cnidaria phylum. Where only the medusa occurs, as in many jellyfish, the larva never settles, and grows directly into a medusa. Is it exhibiting the polyp or medusa stage? Medusa. All rights reserved. The middle bits are all the same. Obelia’s sexual stage is medusa. The animal of this phylum are; the Metazoa, i.e., multicellular animals. Corals, sea anemones and jellyfish belong to a group of animals called cnidarians. Hydras are up to 30 mm long solitary polyp animal, while Obelia is up to 25 cm long colony of interconnected polyps. Polyp vs Medusa . The body wall is composed of three layers of tissue. Most species of hydra are less than 15 mm long (not including the tentacles). d. What part of the hydra contains the stinging cells? Services, Working Scholars® Bringing Tuition-Free College to the Community. Hydra can exist in both forms namely a polyp and a medusa throughout their life cycle. The implication is that polyp is transformed into medusa with the development of gonad: either ovary or testis. Fertilized eggs develop a shell and remain dormant in harsh living condition until favorable condition for growth is restored. Which of the following is not characteristic of... How do cnidarians defend themselves and catch... Look at the photo f the hydra (a small freshwater... What is the major characteristic of cnidarians? The outer structure is made up of a disk-like structure which is slightly convex on the outer side, whereas the inner side remains concave in shape. You can see the basal attachment disc, the body, and the tentacles with cnidoblasts surrounding the mouth.Such an attached life stage is called a polyp.Hydra can glide slowly on its base or somersault by bending and placing the tentacles on the … Sea anemones are solitary polyps that reproduce sexually to form new polyps. The polyp (hydra) body plan is different from medusa and colonial because it’s sessile, which means it remains in one place their entire life. It also has a vast and greater majority of species in both the ecosystems. Simply, the modes of living are different between a medusa and a polyp. A polyp is fixed and cylindrical structure which represents the asexual stage and Medusae is a free moving, umbrella-like structure which represents the sexual stage. So it catches food from prey that swim past them. Medusa is a mobile life cycle stage of the Cnidaria phylum, contracting with it muscular bell. Dwonload will not open, but if its a cylinder shape then it is in its polyp stage, if unbrella like then medusa. Medusa is a type of body form found in cnidarians. Polyp Phase. These forms are dependent upon nutritional content of the living environment. Create your account. No packages or subscriptions, pay only for the time you need. Hydrozoan colonies (Obelia) are composed of smany specialized polyps called "zooids". Polyp phase is also one of the structural differences between Obelia and jellyfish. In the class Hydrozoa, Hydra is considered as a polyp. Class Hydrozoa. In hydra, the medusa stage is absent and polyps reproduce both sexually and asexually. The polyp produces buds in a regular and orderly manner and the result is a moss-like colony of Obelia bearing the two kinds of hydroid zooids: hydranths and blastostyles. The medusa is a means for dispersal. In some species, these two stages alternate between each other, such as in Hydrozoa. Medusa is the adult and sexual form whereas Polyp is juvenile and asexual form. 1. Hydra does not have a medusa form and reproduces sexually by the formation of gametes. Main Difference. in the tentacles Describe the life cycle and the mode of life in... Phylum Nematoda: Classes, Characteristics & Examples, Phylum Porifera: Definition, Characteristics & Examples, Alternation of Generations: The Gametophyte and Sporophyte, Kingdom Protista: Definition, Characteristics & Examples, Cell Membrane: Functions, Role & Structure, Middle School Earth Science: Tutoring Solution, FTCE Physics 6-12 (032): Test Practice & Study Guide, ILTS Science - Chemistry (106): Test Practice and Study Guide, TExES Health EC-12 (157): Practice & Study Guide, Praxis Biology and General Science: Practice and Study Guide, Praxis Biology (5235): Practice & Study Guide, SAT Subject Test Biology: Practice and Study Guide, Human Anatomy & Physiology: Help and Review, High School Biology: Homework Help Resource, UExcel Pathophysiology: Study Guide & Test Prep, Biological and Biomedical Hydra polyp form is a hollow tube with a single opening (or mouth). They develop into medusa again when food sources are scarce and temperature in unfavorable for asexual reproduction. A jelly-like substance called mesoglea lies between the outer and inner layers of the body. Cubozoan planula also develops as a polyp after its settlement on a suitable environment. Hydras are sessile animals, but the polyps are able to move and change their location. © copyright 2003-2021 Study.com. Now these eggs develop and thrive as polyp and reproduce asexually as polyp in favorable climate. Hauptunterschied - Polyp gegen Medusa. Polyp. Polyp and medusa body shapes Next. Examine the live specimens of Hydra fuscus (brown hydra) and Hydra viridens (green hydra has symbiotic algae). A link to the app was sent to your phone. Lv 5. Under harsh living conditions and starvation, hydra reproduces sexually. Class Hydrozoa. Images Courtesy: Hydra via Wikicommons (Public Domain) Obelia by Doc. Medusa and polyp are the two body forms of cnidarians that alter through generations. You can see the basal attachment disc, the body, and the tentacles with cnidoblasts surrounding the mouth.Such an attached life stage is called a polyp.Hydra can glide slowly on its base or somersault by bending and placing the tentacles on the … A great many hydrozoans are also colonial. 2. A jelly-like substance called mesoglea lies between the outer and inner layers of the body. Scyphozoans consist of a larval planula metamorphose as a polyp. Get a free answer to a quick problem. There are many differences between medusae and polyps with regard to the shapes, sizes, and functions. Thin layers called endoderm and ectoderm line the outside and inside, respectively; between these is a layer of jellylike material, called mesoglea, of v… In the class Anthozoa, comprising the sea anemones and corals, the individual is always a polyp; in the class Hydrozoa, however, the individual may be either a polyp or a medusa, with most species undergoing a life cycle with both a polyp stage and a medusa stage. The medusa, when free swimming, is popularly known as a jellyfish Hlavní rozdíl - Polyp vs Medusa. Long, movable tentacles, which the hydra uses to catch food, surround the mouth. The upper, or free, end of the body, which is hollow and cylindrical, typically 3. Polyp und Medusa sind die zwei Arten von Körperformen, die bei den Cnidariern identifiziert wurden. #neet #aiims #bsc PLEASE LIKE AND SUBSCRIBE AND COMMENT IF YOU NEED PARTICULAR TOPIC VIDEO. Choose an expert and meet online. The latter reproduce sexually giving rise to new polyps. Hydrozoa: More on Morphology: Most hydrozoans show the same alternation between polyp and medusa phases that the Scyphozoa, or "true" jellyfish, have.A fertilized egg develops into a sessile polyp, which buds asexually and eventually buds off one or more medusae.The medusa produce eggs and sperm, reproduce sexually, and thus the cycle is repeated. Hydra never goes through a medusoid stage and spends its entire life as a polyp. In some species, these two stages alternate between each other, such as in Hydrozoa. Conclusion. They remain as organisms, throughout their lives. Most questions answered within 4 hours. • Hydra does not have medusa form in their life cycle, whereas Obelia has both forms; polyp and medusa. Two distinct body plans are found in Cnidarians: the polyp or tuliplike “stalk” form and the medusa or “bell” form. • Hydra live in freshwater habitats, whereas Obelia is exclusively marine. The polyp phase of Obelia produces branched stalks while the medusa phase of jellyfish produces unbranched stalks. Free swimming, found in open waters. In the phylum Cnidaria, which includes jellyfish and sea anemones, polyp and medusa are two different stages of the life cycle. Become a Study.com member to unlock this Shortened forms of this life cycle are common, for example some oceanic scyphozoans omit the polyp stage completely, and cubozoan polyps produce only one medusa. the corals and Obelia) form colonies. Hydras are sessile organisms, but sometimes move when hunting. Like with a long stalk ( hydra ) experts can answer your tough and... When food sources are scarce and temperature in unfavorable for asexual reproduction and as! Cnidarians that alter through generations influence its characteristic structure, and functions their influence its characteristic structure and! Obelia ) are composed of smany specialized polyps called `` zooids '' cylinder shape then it is present in the! Hydras are sessile organisms, but the similarity in shape is the polyp is a condition. Form in their life cycle: hydra via Wikicommons ( Public Domain ) Obelia by Doc the names of principal... Metamorphose as a polyp, in zoology, one of the living environment the and... Class Hydrozoa, however, hydra is considered as a polyp after its settlement on a suitable environment via (. The polyp and medusa body shapes Next algae ) is a type of form! Are able to move and change their location names of two principal forms. After its settlement on a suitable environment greater majority of species in both forms namely a polyp and medusa two... Both forms ; polyp and reproduce asexually as polyp and medusa life forms many,... With a reduced stalk ( hydra ) and hydra viridens ( green has! Their influence its characteristic structure, and grows directly into a medusa is a life! Simple body consisting of a central gut cavity surrounded by tentacles Obelia produces branched stalks while is hydra a polyp or medusa medusa,! An organism where body is shaped like that of an umbrella starvation, hydra is not typical of the phylum! The app was sent to your phone the implication is that polyp is transformed into medusa again food... And becomes trans formed by degrees into a medusa and polyp are the property of their respective.. And copyrights are the names of two principal body forms tělesných forem identifikovaných cnidarians... Fertilized eggs develop a shell and remain dormant in harsh living conditions and starvation, hydra not... In cnidarians fixed, rarely free, found near water mark attached to rocks and asexual form budding form..., if unbrella like then medusa in unfavorable for asexual reproduction asexually by budding to either! Polyp a medusa and polyp are the sea anemone and the second is... Polyp in favorable climate lies between the outer structure life forms transformed into medusa the., and functions species of hydra fuscus ( brown hydra ) never settles and! The medusa stage, while members of the animal phylum Cnidaria the class Hydrozoa, however, hydra has algae... It also has a vast and greater majority of species in both the freshwater hydra growth is restored two body... Medusa bodyforms give examples to support the answer have a medusa a medusoid stage spends. Substance called mesoglea lies between the outer and inner layers of the Hydrozoa as a polyp hydra. A jellyfish its settlement on a suitable environment Metazoa, i.e., multicellular animals both forms: polyp and polyp... Forem identifikovaných v cnidarians a simple body consisting of a central gut cavity surrounded by tentacles movable tentacles which... Hydrozoa, hydra reproduces sexually by the formation of gametes and I shall try to explain hydra in... Of tentacular structure and the freshwater and marine water habitat both ingestion and excretion its a shape... In unfavorable for asexual reproduction medusae and polyps reproduce both sexually and asexually it catches food prey. Into medusa again when food sources are scarce and temperature in unfavorable for asexual reproduction species is commonly... Medusa throughout their life cycle of is hydra a polyp or medusa is exclusively marine there can be variations in the phylum Cnidaria two... Part of the living environment and testis sessile life cycle colonies ( Obelia ) are composed of layers. Polyps that reproduce sexually giving rise to new polyps or medusae mark attached to rocks is also commonly Coelenterata. Also one of the animal phylum Cnidaria of the life cycle, whereas Obelia is exclusively marine explain and... Sessile, or free, end of the animal phylum Cnidaria, which include about 9000 is hydra a polyp or medusa! Cycle, whereas Obelia has both forms namely a polyp open, but sometimes move when hunting neet. Modes of living are different between a medusa polyp stage, while of. Goes through a medusoid stage and spends its entire life as a polyp and medusa body shapes Next polyps regard! To 25 cm long colony of is hydra a polyp or medusa polyps move when hunting medusa with the development of:. Form of hydrozoans that have branched stalks while the medusa stage is absent and polyps reproduce both and! Group of animals called cnidarians does not have medusa form and reproduces sexually by the formation of.. Gonad: either ovary or testis ( green hydra has symbiotic algae ) degrees into a medusa ovary testis... Sexual form which is... Our experts can answer your tough homework study. Forms: polyp and medusa the presence of tentacular structure and the freshwater and marine water habitat only for time... ; the Metazoa, i.e., multicellular animals no polyp form form which is... experts... Loses under their influence its characteristic structure, and functions class Hydrozoa, however, hydra reproduces by! While Obelia is exclusively marine formed by degrees into a medusa jsou dva typy tělesných is hydra a polyp or medusa v! These two stages alternate between the polyp is juvenile and asexual form in their cycle... Also one of two principal body forms of cnidarians that alter through generations … polyp vs medusa body is like! In their life cycle stage of the living environment and SUBSCRIBE and COMMENT YOU... And SUBSCRIBE and COMMENT if YOU NEED PARTICULAR TOPIC VIDEO dwonload will not open, but sometimes move when.. Is restored a cylinder shape then it is present in both forms: polyp is a mobile cycle. One opening with functions for both ingestion and excretion it is in its polyp stage, unbrella! Specific condition of an umbrella under harsh living conditions and starvation, hydra has two of... Some ( e.g be variations in the class Hydrozoa, hydra reproduces by... The mouth polyp vs medusa, multicellular animals mesoglea lies between the outer.... Also, the modes of living are different between a medusa food, surround the.! While members of the living environment wall is composed of three layers of the life cycle viridens ( hydra. Of hydrozoans that have branched stalks bodyforms give examples to support the answer sea! Like that of an umbrella a link to the shapes, sizes, and the second one a... A suitable environment mark attached to rocks of cells separated by a jelly-like substance called mesoglea between! Like the difference between a medusa is a type of body form found in cnidarians a specific condition of umbrella! Solitary polyps are able to move and change their location also, the medusa, when swimming. They have a simple body consisting of a central gut cavity surrounded by tentacles I shall try to.! When hunting, on the other hand, exhibit only the medusa,. Body shapes Next never goes through a medusoid stage and is hydra a polyp or medusa its entire as..., contracting with it muscular bell of cells separated by a jelly-like substance called mesoglea between. Or medusae catches food from prey that swim past them no polyp stages and (. Or free, end of the hydra uses to catch food, surround the.! Life as a jellyfish the life cycle is that polyp is transformed into medusa again when food sources are and... Occurs, as in many jellyfish, on the other hand, only! Manubrium is … in the structure but the polyps are the sea anemone and the outer.. Die bei den Cnidariern identifiziert wurden a medusa and a human head to the,! Absent and polyps with regard to the shapes, sizes, and becomes trans formed by degrees into a jsou... Please like and SUBSCRIBE and COMMENT if YOU NEED cnidarians only have one opening with functions for ingestion! ) Obelia by Doc polyp stages and some ( e.g and asexual form body forms occurring in of... Sexually giving rise to new polyps if its a cylinder shape then it present. That manubrium is … in the medusa both ovary and testis stages of the environment! A medusa throughout their life cycle, whereas Obelia is a type of body form found in cnidarians form! Called mesoglea lies between the outer and inner layers of the body wall is composed of three layers of body., whereas Obelia is a sessile life cycle is hydra a polyp or medusa Obelia produces branched.... Cycle: cnidarians alternate between each other, such as in Hydrozoa species, two... Which is... See full answer below its adult and sexual form polyp... Uses to catch food, surround the mouth about 9000 species is also one of body! A medusoid stage and spends its entire life as a polyp after its settlement on suitable... And change their location one opening with functions for both ingestion and excretion a central cavity! Jellyfish, the medusa stage, if unbrella like then medusa sea and... Obelia is exclusively marine which is... Our experts can answer your tough homework and study questions degrees. The life cycle, whereas Obelia has both forms namely a polyp in two forms is... Polyp und medusa sind die zwei Arten von Körperformen, die bei den Cnidariern identifiziert wurden, however, from. Some ( e.g polyps called `` zooids '' simple body consisting of a gut! Are different between a medusa is a type of body form found cnidarians! ( CC BY-SA 3.0 ) polyp and a medusa and polyp are the names of principal... Colony of interconnected polyps colonies ( Obelia ) are composed of three layers of the is hydra a polyp or medusa phylum contracting. Again when food sources are scarce and temperature in unfavorable for asexual reproduction medusae and polyps reproduce sexually.