Juvenile (organism)

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Young wild boar suckling from an adult female; here, juvenile colouring acts as a form of camouflage Wildsau mit Frischling.jpg
Young wild boar suckling from an adult female; here, juvenile colouring acts as a form of camouflage
Juvenile (left) and adult (right) leaves of stone pine Pinus pinea foliage.jpg
Juvenile (left) and adult (right) leaves of stone pine
Juvenile alligator in the Everglades Juvenile alligator II.jpg
Juvenile alligator in the Everglades

A juvenile is an individual organism (especially an animal) that has not yet reached its adult form, sexual maturity or size. Juveniles can look very different from the adult form, particularly in colour, and may not fill the same niche as the adult form. [1] In many organisms the juvenile has a different name from the adult (see List of animal names).

Some organisms reach sexual maturity in a short metamorphosis, such as ecdysis in many insects and some other arthropods. For others, the transition from juvenile to fully mature is a more prolonged process—puberty in humans and other species (like higher primates and whales), for example. In such cases, juveniles during this transformation are sometimes called subadults.

Many invertebrates cease development upon reaching adulthood. The stages of such invertebrates are larvae or nymphs.

In vertebrates and some invertebrates (e.g. spiders), larval forms (e.g. tadpoles) are usually considered a development stage of their own, and "juvenile" refers to a post-larval stage that is not fully grown and not sexually mature. In amniotes, the embryo represents the larval stage. Here, a "juvenile" is an individual in the time between hatching/birth/germination and reaching maturity.

Examples

Related Research Articles

<span class="mw-page-title-main">Metamorphosis</span> Profound change in body structure during the postembryonic development of an organism

Metamorphosis is a biological process by which an animal physically develops including birth transformation or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some insects, jellyfish, fish, amphibians, mollusks, crustaceans, cnidarians, echinoderms, and tunicates undergo metamorphosis, which is often accompanied by a change of nutrition source or behavior. Animals can be divided into species that undergo complete metamorphosis ("holometaboly"), incomplete metamorphosis ("hemimetaboly"), or no metamorphosis ("ametaboly").

Neoteny, also called juvenilization, is the delaying or slowing of the physiological, or somatic, development of an organism, typically an animal. Neoteny is found in modern humans compared to other primates. In progenesis or paedogenesis, sexual development is accelerated.

<span class="mw-page-title-main">Ontogeny</span> Origination and development of an organism

Ontogeny is the origination and development of an organism, usually from the time of fertilization of the egg to adult. The term can also be used to refer to the study of the entirety of an organism's lifespan.

<span class="mw-page-title-main">Reproduction</span> Biological process by which new organisms are generated from one or more parent organisms

Reproduction is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. There are two forms of reproduction: asexual and sexual.

<span class="mw-page-title-main">Larva</span> Juvenile form of distinct animals before metamorphosis

A larva is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle.

Development of the human body is the process of growth to maturity. The process begins with fertilization, where an egg released from the ovary of a female is penetrated by a sperm cell from a male. The resulting zygote develops through mitosis and cell differentiation, and the resulting embryo then implants in the uterus, where the embryo continues development through a fetal stage until birth. Further growth and development continues after birth, and includes both physical and psychological development that is influenced by genetic, hormonal, environmental and other factors. This continues throughout life: through childhood and adolescence into adulthood.

<span class="mw-page-title-main">Adult</span> Being that is fully grown

An adult is a human or other animal that has reached full growth. The biological definition of the word means an animal reaching sexual maturity and thus capable of reproduction. In the human context, the term adult has meanings associated with social and legal concepts. In contrast to a non-adult or "minor", a legal adult is a person who has attained the age of majority and is therefore regarded as independent, self-sufficient, and responsible. They may also be regarded as "majors". The typical age of attaining legal adulthood is 18, although definition may vary by legal rights, country, and psychological development.

Sexual maturity is the capability of an organism to reproduce. In humans, it is related to both puberty and adulthood. However, puberty is the process of biological sexual maturation, while the concept of adulthood is generally based on broader cultural definitions.

<span class="mw-page-title-main">Veliger</span> Larval stage of some snails

A veliger is the planktonic larva of many kinds of sea snails and freshwater snails, as well as most bivalve molluscs (clams) and tusk shells.

Sexual characteristics are physical traits of an organism which are indicative of or resultant from biological sexual factors. These include both primary sex characteristics, such as gonads, and secondary sex characteristics.

In Islamic legal terminology, bāligh or mukallāf or muhallāq or murāhiq or muhtalim refers to someone who has reached maturity or puberty, and has full responsibility under Islamic law.

<span class="mw-page-title-main">Competition (biology)</span> Interaction where the fitness of one organism is lowered by the presence of another organism

Competition is an interaction between organisms or species in which both require a resource that is in limited supply. Competition lowers the fitness of both organisms involved since the presence of one of the organisms always reduces the amount of the resource available to the other.

<span class="mw-page-title-main">Eastern mosquitofish</span> Species of fish

The eastern mosquitofish is a species of freshwater fish, closely related to the western mosquitofish, Gambusia affinis. It is a member of the family Poeciliidae of order Cyprinodontiformes. The eastern mosquitofish is native to the eastern and southern United States from Florida to Pennsylvania and inland to Alabama and Tennessee, while the western mosquitofish has a larger distribution throughout the United States.

<i>Maja squinado</i> Species of crab

Maja squinado is a species of migratory crab found in the north-east Atlantic and the Mediterranean Sea. The appearance of the European spider crab is similar to the much larger Japanese spider crab, although the latter belongs to a different family of crabs, the Inachidae.

<i>Isostichopus fuscus</i> Species of sea cucumber

Isostichopus fuscus, commonly known as the brown sea cucumber, is a species of sea cucumber in the family Stichopodidae native to the eastern Pacific. It was first described to science by German biologist Hubert Ludwig in 1875.

<span class="mw-page-title-main">Sessility (motility)</span> Property of organisms that do not possess a means of self-locomotion and are normally immobile

Sessility is the biological property of an organism describing its lack of a means of self-locomotion. Sessile organisms for which natural motility is absent are normally immobile. This is distinct from the botanical concept of sessility, which refers to an organism or biological structure attached directly by its base without a stalk.

Puberty is the process of physical changes through which a child's body matures into an adult body capable of sexual reproduction. It is initiated by hormonal signals from the brain to the gonads: the ovaries in a female, the testicles in a male. In response to the signals, the gonads produce hormones that stimulate libido and the growth, function, and transformation of the brain, bones, muscle, blood, skin, hair, breasts, and sex organs. Physical growth—height and weight—accelerates in the first half of puberty and is completed when an adult body has been developed. Before puberty, the external sex organs, known as primary sexual characteristics, are sex characteristics that distinguish males and females. Puberty leads to sexual dimorphism through the development of the secondary sex characteristics, which further distinguish the sexes.

<span class="mw-page-title-main">Juvenile fish</span> Young fish

Fish go through various life stages between fertilization and adulthood. The life of fish start as spawned eggs which hatch into immotile larvae. These larval hatchlings are not yet capable of feeding themselves and carry a yolk sac which provides stored nutrition. Before the yolk sac completely disappears, the young fish must mature enough to be able to forage independently. When they have developed to the point where they are capable of feeding by themselves, the fish are called fry. When, in addition, they have developed scales and working fins, the transition to a juvenile fish is complete and it is called a fingerling, so called as they are typically about the size of human fingers. The juvenile stage lasts until the fish is fully grown, sexually mature and interacting with other adult fish.

<span class="mw-page-title-main">Ontogenetic niche shift</span> Ecological phenomenon

Ontogenetic niche shift is an ecological phenomenon where an organism changes its diet or habitat during its ontogeny (development). During the ontogenetic niche shifting an ecological niche of an individual changes its breadth and position. The best known representatives of taxa that exhibit some kind of the ontogenetic niche shift are fish, insects and amphibians. A niche shift is thought to be determined genetically, while also being irreversible. Important aspect of the ONS is the fact, that individuals of different stages of a population utilize different kind of resources and habitats. The term was introduced in a 1984 paper by biologists Earl E. Werner and James F. Gilliam.

<span class="mw-page-title-main">Precociality and altriciality</span> States of newborn mobility and independence

In the biology of birds and mammals, altricial species are those in which the young are underdeveloped at the time of birth, but with the aid of their parents mature after birth. Precocial species are those in which the young are relatively mature and mobile from the moment of birth or hatching. They are normally nidifugous, meaning that they leave the nest shortly after birth or hatching. These categories form a continuum, without distinct gaps between them.

References

  1. Jeglinski, Jana; Goetz, Kimberley; Werner, Christiane; Costa, Daniel; Trillmich, Fritz (January 2013). "Same size – same niche? Foraging niche separation between sympatric juvenile Galapagos sea lions and adult Galapagos fur seals". Journal of Animal Ecology. 82 (3): 694–706. doi: 10.1111/1365-2656.12019 . PMID   23351022.