A cicada in the process of shedding.

Metamorphosis is a biological process by which an animal physically develops after birth or hatching, involving a conspicuous and relatively abrupt change in the animal's form or structure through cell growth and differentiation. Some insects, amphibians, molluscs, crustaceans, echinoderms and tunicates undergo metamorphosis, which is usually (but not always) accompanied by a change of habitat or behaviour. Image File history File linksMetadata Download high-resolution version (1131x978, 270 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Metamorphosis Metadata This file contains additional information, probably added from the digital camera or scanner used to create... Image File history File linksMetadata Download high-resolution version (1131x978, 270 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Metamorphosis Metadata This file contains additional information, probably added from the digital camera or scanner used to create... Subfamilies Tettigadinae Cicadinae Cicadettinae A cicada is any of several insects of the order Hemiptera, suborder Auchenorrhyncha, in the superfamily Cicadoidea, with small eyes wide apart on the head and usually transparent, well-veined wings. ... A biological process is a process of a living organism. ... Animalia redirects here. ... Views of a Foetus in the Womb, Leonardo da Vinci, ca. ... Birth is the process in animals by which an offspring is expelled from the body of its mother. ... The term cell growth is used in two different ways in biology. ... Cellular differentiation is a concept from developmental biology describing the process by which cells acquire a type. The morphology of a cell may change dramatically during differentiation, but the genetic material remains the same, with few exceptions. ... Orders See taxonomy Insects (Class Insecta) are a major group of arthropods and the most diverse group of animals on the Earth, with over a million described species—more than all other animal groups combined. ... For other uses, see Amphibian (disambiguation). ... Classes Caudofoveata Aplacophora Polyplacophora Monoplacophora Bivalvia Scaphopoda Gastropoda Cephalopoda † Rostroconchia † Helcionelloida † ?Bellerophontidae The molluscs (British spelling) or mollusks (American spelling) are the large and diverse phylum Mollusca, which includes a variety of familiar animals well-known for their decorative shells or as seafood. ... Classes & Subclasses Branchiopoda Phyllopoda Sarsostraca Remipedia Cephalocarida Maxillopoda Thecostraca Tantulocarida Branchiura Pentastomida Mystacocarida Copepoda Ostracoda Myodocopa Podocopa Malacostraca Phyllocarida Hoplocarida Eumalacostraca The crustaceans (Crustacea) are a large group of arthropods, comprising approximately 52,000 described species [1], and are usually treated as a subphylum [2].They include various familiar animals... Classes  ?Helicoplacoidea †  ?Arkarua †  ?Homalozoa † Eleutherozoa Asteroidea Concentricycloidea Echinoidea Holothuroidea Ophiuroidea Pelmatozoa Crinoidea Edrioasteroidea† Blastoidea † Cystoidea † Eocrinoidea † † = extinct Echinoderms . ... Classes Ascidiacea Thaliacea Appendicularia Sorberacea Urochordata (sometimes known as tunicata and commonly called urochordates, tunicates, sea squirts or cunji) is the subphylum of saclike filter feeders with incurrent and excurrent siphons. ... Habitat (from the Latin for it inhabits) is the place where a particular species lives and grows. ... Behavior or behaviour refers to the actions or reactions of an object or organism, usually in relation to the environment. ...

Scientific usage of the term is exclusive, and is not applied to general aspects of cell growth, including rapid growth spurts. References to "metamorphosis" in mammals is imprecise and only colloquial. According to Williamson, metamorphosis represents a change in taxon during development. The term cell growth is used in two different ways in biology. ... Puberty refers to the process of physical changes by which a childs body becomes an adult body capable of reproduction. ... Subclasses Allotheria* Order Multituberculata (extinct) Order Volaticotheria (extinct) Order Palaeoryctoides (extinct) Order Triconodonta (extinct) Order Docodonta (extinct) Prototheria Order Monotremata Theria Infraclass Trituberculata (extinct) Infraclass Marsupialia Infraclass Eutheria The mammals are the class of vertebrate animals characterized by the production of milk in females for the nourishment of young, from...

Insect metamorphosis

Metamorphosis usually proceeds in distinct stages, starting with larva or nymph, optionally passing through pupa, and ending as adult. There are two main types of metamorphosis in insects, hemimetabolism and holometabolism. Binomial name Musca domestica Linnaeus, 1758 The housefly (also house fly or house-fly), Musca domestica, is the most common fly occurring in homes, the most familiar of all flies and indeed one of the most widely distributed animals; it is a pest that can facilitate serious diseases. ... Subfamilies Chilocorinae Coccidulinae Coccinellinae Epilachninae Scymininae Sticholotidinae etc. ... Binomial name Danaus plexippus (Linnaeus, 1758) The Monarch butterfly (Danaus plexippus) is a well-known North American butterfly. ... Species See text Magicicada is the genus of the 13- and 17- year periodical cicadas of eastern North America. ... Suborders Suborder Schistonota  Superfamily Baetoidea    Siphlonuridae    Baetidae    Oniscigastridae    Ameletopsidae    Ametropodidae  Superfamily Heptagenioidea    Coloburiscidae    Oligoneuriidae    Isonychiidae    Heptageniidae  Superfamily Leptophlebioidea    Leptophlebiidae  Superfamily Ephemeroidea    Behningiidae    Potamanthidae    Euthyplociidae    Polymitarcydae    Ephemeridae    Palingeniidae Suborder Pannota  Superfamily Ephemerelloidea    Ephemerellidae    Leptohyphidae    Tricorythidae  Superfamily Caenoidea    Neoephemeridae    Baetiscidae    Caenidae    Prosopistomatidae The mayflies belong to the order Ephemeroptera (Ephemeroptera: Greek Ephemeros... Families Blaberidae Blattellidae Blattidae Cryptocercidae Polyphagidae Nocticolidae Cockroaches (or simply roaches) are insects of the Order Blattodea. ... A larva (Latin; plural larvae) is a juvenile form of animal with indirect development, undergoing metamorphosis (for example, insects or amphibians). ... In Greek mythology, a nymph is any member of a large class of female nature entities, either bound to a particular location or landform or joining the retinue of a god or goddess. ... Cockchafer (Melolontha melolontha) pupa Chrysalis redirects here: for other meanings see Chrysalis (disambiguation). ... A young woman who is 18 years old. ... Hemimetabolism, also called incomplete metamorphism, is a term used to describe insects with a specific type of life cycle, including three distinct stages: the embryo, nymph, and the adult stage, or the imago. ... Holometabolism, also called complete metamorphism, is a term applied to insect groups to describe the specific kind of insect development which includes four life stages - as an embryo, a larva, a pupa and an imago. ...

The immature stages of a species that metamorphoses are usually called larvae. But in the complex metamorphosis of many insect species, only the first stage is called a larva and sometimes even that bears a different name; the distinction depends on the nature of the metamorphosis. A larva (Latin; plural larvae) is a juvenile form of animal with indirect development, undergoing metamorphosis (for example, insects or amphibians). ...

In hemimetabolism, the development of larva often proceeds in repeated stages of growth and ecdysis (moulting), these stages are called instars. The juvenile forms closely resemble adults, but are smaller and, if the adult has wings, lack wings. This process is also known as "simple", "gradual" or "incomplete" metamorphosis. The differences between juveniles in different instars are small, often just differences in body proportions and the number of segments. Ecdysis is the molting of the cuticula in arthropods and related groups (Ecdysozoa). ... An instar is a developmental stage of arthropods, such as insects, between each molt. ...

In holometabolism, the larvae differ markedly from the adults. Insects which undergo holometabolism pass through a larval stage, then enter an inactive state called pupa, or chrysalis, and finally emerge as adults. Holometabolism is also known as "complete" and "complex" metamorphosis. Whilst inside the pupa, the insect will excrete digestive juices, to destroy much of the larvas body, leaving a few cells intact. The remaining cells will begin the growth of the adult, using the nutrients from the broken down larva. This process of cell death is called histolysis, and cell regrowth histogenesis. An Introduction to Histogenesis Histogenesis is defined as the formation of tissues and organs from undifferentiated cells (Encarta Dictionary). ...

Whether the insect spends more time in its adult stage or in its juvenile form depends on the species. Notable examples are the mayfly, whose non-eating, adult stage lives for one day, and the cicada, whose juvenile stage live underground for 13 or 17 years. These species have incomplete metamorphosis. Typically,though not exclusively, species in which the adult form outlives the juvenile form undergo complex metamorphosis. Suborders Suborder Schistonota  Superfamily Baetoidea    Siphlonuridae    Baetidae    Oniscigastridae    Ameletopsidae    Ametropodidae  Superfamily Heptagenioidea    Coloburiscidae    Oligoneuriidae    Isonychiidae    Heptageniidae  Superfamily Leptophlebioidea    Leptophlebiidae  Superfamily Ephemeroidea    Behningiidae    Potamanthidae    Euthyplociidae    Polymitarcydae    Ephemeridae    Palingeniidae Suborder Pannota  Superfamily Ephemerelloidea    Ephemerellidae    Leptohyphidae    Tricorythidae  Superfamily Caenoidea    Neoephemeridae    Baetiscidae    Caenidae    Prosopistomatidae The mayflies belong to the order Ephemeroptera (Ephemeroptera: Greek Ephemeros... Subfamilies Tettigadinae Cicadinae Cicadettinae A cicada is any of several insects of the order Hemiptera, suborder Auchenorrhyncha, in the superfamily Cicadoidea, with small eyes wide apart on the head and usually transparent, well-veined wings. ...

Many observations have indicated that cell death plays a considerable role during physiological processes of multicellular organisms, particularly during embryogenesis and metamorphosis. Programmed cell death (PCD) is the deliberate suicide of an unwanted cell in a multicellular organism. ... Embryogenesis is the process by which the embryo is formed and develops. ...

Pieris rapae larva ImageMetadata File history File links Download high resolution version (1280x960, 115 KB) Photo by Christian Bauer source File links The following pages link to this file: Metamorphosis (biology) ... Binomial name Pieris rapae Linnaeus, 1758 The Small White butterfly, Pieris rapae, flies April-May and July-August. ... A larva (Latin; plural larvae) is a juvenile form of animal with indirect development, undergoing metamorphosis (for example, insects or amphibians). ...

Pieris rapae pupa ImageMetadata File history File links Download high resolution version (960x1280, 121 KB) Photo by Christian Bauer source File links The following pages link to this file: Metamorphosis (biology) ... Cockchafer (Melolontha melolontha) pupa Chrysalis redirects here: for other meanings see Chrysalis (disambiguation). ...

Pieris rapae pupa, ready to hatch. ImageMetadata File history File links Download high resolution version (960x1280, 114 KB) Photo by Christian Bauer source File links The following pages link to this file: Metamorphosis (biology) ...

A Pieris rapae adult ImageMetadata File history File links Download high resolution version (1280x960, 94 KB) Photo by Christian Bauer source File links The following pages link to this file: Metamorphosis (biology) ... A young woman who is 18 years old. ...

Hormonal control

Insect growth and metamorphosis are controlled by hormones synthesized by endocrine glands near the front of the body. Orders See taxonomy Insects (Class Insecta) are a major group of arthropods and the most diverse group of animals on the Earth, with over a million described species—more than all other animal groups combined. ... Norepinephrine A hormone (from Greek όρμή - to set in motion) is a chemical messenger from one cell (or group of cells) to another. ... The endocrine system is a control system of ductless endocrine glands that secrete chemical messengers called hormones that circulate within the body via the bloodstream to affect distant organs. ... A gland is an organ in an animals body that synthesizes a substance for release such as hormones, often into the bloodstream (endocrine gland) or into cavities inside the body or its outer surface (exocrine gland). ...

Some cells of an insect's brain secrete a hormone that activates thoracic glands, which secrete a second hormone, usually Ecdysone (a steroid), that induces metamorphosis. Drawing of the structure of cork as it appeared under the microscope to Robert Hook from Micrographia which is the origin of the word cell. Cells in culture, stained for keratin (red) and DNA (green). ... In animals the brain, or encephalon (Greek for in the head), is the control center of the central nervous system, responsible for thought. ... Diagram of a tsetse fly, showing the head, thorax and abdomen The thorax is a division of an animals body that lies between the head and the abdomen. ... Ecdysone is a prohormone of the major insect moulting hormone 20-hydroxyecdysone, which is secreted from the prothoracic glands. ... Steroid skeleton of lanosterol. ...

Moreover, the corpora allata produce the juvenile hormone, whose effect is to prevent the development of adult characteristics while allowing ecdysis. Therefore, the insect is subject to a series of moult, controlled by Ecdysone, until the production of juvenile hormone ceases and metamorphosis occurs. In insects, juvenile hormone (also neotenin) refers to a group of hormones which ensure growth of the larva, while preventing metamorphosis. ... Ecdysis is the molting of the cuticula in arthropods and related groups (Ecdysozoa). ... Ecdysone is a prohormone of the major insect moulting hormone 20-hydroxyecdysone, which is secreted from the prothoracic glands. ...

Amphibian metamorphosis

Dendrobates lamasi tadpole undergoing metamorphosis.

Amphibian metamorphosis undergoes a single change from larvae, called a tadpole, to an adult. In the typical amphibian lifecycle, eggs are laid in water. The tadpole then emerges from the egg, and swims freely within the water. The tadpole has gills, a tail and a small circular mouth. The tadpole will grow, until it begins metamorphosis. Metamorphosis begins with the development of the hind legs, then the front legs. The lungs develop, and the tadpole begins to swim to the surface of the water to breathe. The intestine shortens to accommodate a carnivorous diet, and the eyes migrate rostrally and dorsally. In frogs the tail is absorbed by the body, for the last stage of metamorphosis. Image File history File linksMetadata No higher resolution available. ... Image File history File linksMetadata No higher resolution available. ... Subclasses and Orders    Order Temnospondyli - extinct Subclass Lepospondyli - extinct Subclass Lissamphibia    Order Anura    Order Caudata    Order Gymnophiona Amphibians (class Amphibia; from Greek αμφις both and βιος life) are a taxon of animals that include all living tetrapods (four-legged vertebrates) that do not have amniotic eggs, are ectotherms, and generally spend part... Tadpole of Littlejohns Tree Frog (Litoria littlejohni) A tadpole (also known as a pollywog or polliwog) is a larval amphibian, the juvenile form of a frog, toad, newt, salamander, or caecilian. ... Distribution of frogs (in black) Suborders Archaeobatrachia Mesobatrachia Neobatrachia - List of Anuran families The frog is an amphibian in the order Anura (meaning tail-less from Greek an-, without + oura, tail), formerly referred to as Salientia (Latin saltare, to jump). ...

There are many derivations from the typical amphibian lifecycle. Some species of salamander do not need to metamorphose to be sexually mature, and will only metamorphose under certain environmental stresses. Many species of frog from the tropics lay their eggs on land, where the tadpoles undergo metamorphosis within the egg. Once they hatch, they are immature copies of the adults, sometimes possessing a tail which is re-absorbed in a couple of days. Suborders Cryptobranchoidea Salamandroidea Sirenoidea Salamander is the common name applied to approximately 500 amphibians with slender bodies, short legs, and long tails. ... The tropics are the geographic region of the Earth centered on the equator and limited in latitude by the two tropics: the Tropic of Cancer in the northern hemisphere and the Tropic of Capricorn in the southern hemisphere. ...

See also

• Ametabolism
• Hypermetamorphosis
• Morphogenesis

Metabolism whereby there is slight or no metamorphosis ... Hypermetamorphosis is the form of metamorphosis done by certain beetles, notably Meloidae and Rhipiphoridae, and the Strepsiptera. ... Morphogenesis is also the name of a band. ...

References

• Davies, R.G., Outlines of Entomology, Chapman and Hall: chapter 3

Williamson D I (2003). "The Origins of Larvae", xviii + 261 pp, ISBN 1-4020-1514-3. Kluwer. Dordrecht.

External links

• Description of metamorphosis and its different forms
• Info on butterflies and butterfly metamorphosis
• Info on insect hormones