The ovipositor is an organ
Organ (anatomy)
In biology, an organ is a collection of tissues joined in structural unit to serve a common function. Usually there is a main tissue and sporadic tissues . The main tissue is the one that is unique for the specific organ. For example, main tissue in the heart is the myocardium, while sporadic are...

 used by some animal
Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...

s for oviposition
Oviposition is the process of laying eggs by oviparous animals.Some arthropods, for example, lay their eggs with an organ called the ovipositor.Fish , amphibians, reptiles, birds and monetremata also lay eggs....

, i.e., the laying of eggs
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...

. It consists of a maximum of three pairs of appendages formed to transmit the egg, to prepare a place for it, and to place it properly. In some of the insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...

s the organ is used merely to attach the egg to some surface, but in many parasitic species (primarily in wasp
The term wasp is typically defined as any insect of the order Hymenoptera and suborder Apocrita that is neither a bee nor an ant. Almost every pest insect species has at least one wasp species that preys upon it or parasitizes it, making wasps critically important in natural control of their...

s and other Hymenoptera
Hymenoptera is one of the largest orders of insects, comprising the sawflies, wasps, bees and ants. There are over 130,000 recognized species, with many more remaining to be described. The name refers to the heavy wings of the insects, and is derived from the Ancient Greek ὑμήν : membrane and...

) it is a piercing organ as well. It is used by grasshopper
The grasshopper is an insect of the suborder Caelifera in the order Orthoptera. To distinguish it from bush crickets or katydids, it is sometimes referred to as the short-horned grasshopper...

s to force a burrow in the earth to receive the eggs and by cicada
A cicada is an insect of the order Hemiptera, suborder Auchenorrhyncha , in the superfamily Cicadoidea, with large eyes wide apart on the head and usually transparent, well-veined wings. There are about 2,500 species of cicada around the world, and many of them remain unclassified...

s to pierce the wood
Wood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers embedded in a matrix of lignin which resists compression...

 of twigs for a similar purpose. Both long-horned grasshoppers
Ensifera is a suborder of the order Orthoptera, comprising insects commonly known as crickets, katydids and bush crickets. "Ensifer" means "sword bearer" in Latin, and refers to the typically elongated and blade-like ovipositor of the females...

 and sawflies cut the tissues
Biological tissue
Tissue is a cellular organizational level intermediate between cells and a complete organism. A tissue is an ensemble of cells, not necessarily identical, but from the same origin, that together carry out a specific function. These are called tissues because of their identical functioning...

 of plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...

s by means of the ovipositor. None of these examples is quite as remarkable as the wasp genus Megarhyssa
Megarhyssa is a genus of large ichneumon wasps, with some species known for having the longest ovipositors of any insects. They are idiobiont endoparasitoids of the larvae of wood-boring horntail wasps.-External links:* * -Species:...

, the females of which have a slender ovipositor (terebra) several inches long that is used to drill into the wood of tree trunks. These species are parasitic in the larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...

l stage on the larvae of horntail
Horntail or wood wasp is the common name for any of the 100 non-social species of the family Siricidae, of the order Hymenoptera, a type of xylophagous sawfly...

 wasps, hence the egg must be deposited directly into the host's body as it is feeding.

The sting of Hymenoptera (wasp
The term wasp is typically defined as any insect of the order Hymenoptera and suborder Apocrita that is neither a bee nor an ant. Almost every pest insect species has at least one wasp species that preys upon it or parasitizes it, making wasps critically important in natural control of their...

s, hornet
Hornets are the largest eusocial wasps; some species can reach up to in length. The true hornets make up the genus Vespa and are distinguished from other vespines by the width of the vertex , which is proportionally larger in Vespa and by the anteriorly rounded gasters .- Life cycle :In...

s, bee
Bees are flying insects closely related to wasps and ants, and are known for their role in pollination and for producing honey and beeswax. Bees are a monophyletic lineage within the superfamily Apoidea, presently classified by the unranked taxon name Anthophila...

s, and some ant
Ants are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than...

s) is also an ovipositor, in this case highly modified and associated with poison
In the context of biology, poisons are substances that can cause disturbances to organisms, usually by chemical reaction or other activity on the molecular scale, when a sufficient quantity is absorbed by an organism....

A gland is an organ in an animal's body that synthesizes a substance for release of substances such as hormones or breast milk, often into the bloodstream or into cavities inside the body or its outer surface .- Types :...

s that are used to paralyze prey. This would allow eggs to be laid without the host fighting back, and probably also to suppress the host's immune system so that it can't destroy the eggs or shake off the paralysis. However, in virtually all stinging hymenopterans, the ovipositor is no longer used for egg-laying.

Some roach
Roach (fish)
The Common Roach is a freshwater and brackish water fish native to most of Europe and western Asia...

-like fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

, such as bitterling
The Amur Bitterling, Rhodeus sericeus, is a small fish of the carp family. It is sometimes just called "bitterling", but this is wrong: for one thing, it dates back to the time when the European Bitterling was still considered conspecific with R. sericeus, for another, "bitterling" properly refers...

s, have an ovipositor as a tubular extension of the genital orifice in the breeding season for depositing eggs in the mantle cavity of the pond mussel
The common name mussel is used for members of several families of clams or bivalvia mollusca, from saltwater and freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other edible clams, which are often more or less rounded or oval.The...

. Seahorse
Seahorses compose the fish genus Hippocampus within the family Syngnathidae, in order Syngnathiformes. Syngnathidae also includes the pipefishes. "Hippocampus" comes from the Ancient Greek hippos meaning "horse" and kampos meaning “sea monster”.There are nearly 50 species of seahorse...

s have an ovipositor serving a similar purpose.

Media depictions

The Alien queen in the film Aliens
Aliens (film)
Aliens is a 1986 science fiction action film directed by James Cameron and starring Sigourney Weaver, Carrie Henn, Michael Biehn, Lance Henriksen, William Hope, and Bill Paxton...

 is shown suspended in her nest using a giant ovipositor to lay the alien eggs. Ripley
Ellen Ripley
Ellen Ripley is a fictional character and the main protagonist of the Alien film series played by American actress Sigourney Weaver. The character was heralded as a seminal role for challenging gender roles, particularly in the science fiction genre, and remains Weaver's most famous role to...

 subsequently destroys it with a volley of grenades.

The British Broadcasting Corporation is a British public service broadcaster. Its headquarters is at Broadcasting House in the City of Westminster, London. It is the largest broadcaster in the world, with about 23,000 staff...

 documentary Walking with Dinosaurs
Walking with Dinosaurs
Walking with Dinosaurs is a six-part documentary television miniseries that was produced by BBC, narrated by Kenneth Branagh, and first aired in the United Kingdom, in 1999. The series was subsequently aired in North America on the Discovery Channel in 2000, with Branagh's voice replaced with that...

portrayed a Diplodocus
Diplodocus , or )is a genus of diplodocid sauropod dinosaur whose fossils were first discovered in 1877 by S. W. Williston. The generic name, coined by Othniel Charles Marsh in 1878, is a Neo-Latin term derived from Greek "double" and "beam", in reference to its double-beamed chevron bones...

mother using an ovipositor to lay her eggs.
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