live-bearer

live-bearer

fish
      any of the numerous live-bearing topminnows of the family Poeciliidae (order Atheriniformes), found only in the New World and most abundantly in Mexico and Central America. Most of the many species are rather elongated, and all are small, the largest growing to only about 15 centimetres (6 inches) long.

      Live-bearers resemble the related killifish (family Cyprinodontidae) but differ in their mode of reproduction and in the possession, by the males, of a specialized organ (gonopodium) derived from the anal fin and used to place the sperm in the body of the female. The family is also noted for the sometimes considerable differences between the sexes, the female often being larger and less brightly coloured. The young may number from a few to 100 or more, and several broods may result from one mating.

      Live-bearers are usually omnivorous; some, such as the mosquito fish (q.v.), feed heavily on mosquito larvae and are used to control these pests. Many live-bearers are popular aquarium fishes; among the best known are the guppy, molly, platy, and swordtail (qq.v.).

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Universalium. 2010.

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Look at other dictionaries:

  • live-bearer — n. Any fish of the family {Poeciliiidae}, small usually brightly colored viviparous surface feeding fishes of fresh or brackish warm waters, often used in mosquito control. Syn: topminnow, poeciliid fish, poeciliid. [WordNet 1.5] …   The Collaborative International Dictionary of English

  • live-bearer — noun Date: 1934 a fish that brings forth living young rather than eggs; especially any of a family (Poeciliidae) of numerous small surface feeding fishes (as a molly or swordtail) …   New Collegiate Dictionary

  • live-bearer — noun small usually brightly colored viviparous surface feeding fishes of fresh or brackish warm waters; often used in mosquito control • Syn: ↑topminnow, ↑poeciliid fish, ↑poeciliid • Hypernyms: ↑cypriniform fish • Hyponyms: ↑mosquito …   Useful english dictionary

  • facultative lecithotrophic live bearer — a reproductive guild (q.v.) where eggs are sometimes fertilised internally by accident when gonopores of otherwise oviparous fish are close together. Eggs may be retained in the female and some early development occurs there (rarely beyond… …   Dictionary of ichthyology

  • obligate lecithotrophic live bearer — a reproductive guild (q.v.) where eggs are fertilised internally and develop in the female until the end of the embryonic phase or later. There is no maternal foetal nutrient transfer (yolk provides food). There is some specialisation for… …   Dictionary of ichthyology

  • lecithotrophic live bearer — facultative and obligate lecitrophic live bearers (both q.v.) are two reproductive guilds (q.v.) …   Dictionary of ichthyology

  • combined live bearer — a reproductive guild (q.v.) with eggs having a large yolk volume and density (lecithotrophy) combined with feeding on sibling remains, histrotrophe and with simple placenta like structures. Large specialised young are produced at parturition, e.g …   Dictionary of ichthyology

  • embryonic cannibal live bearer — a reproductive guild (q.v.) where only one or a few eggs from the ovary develop into a juvenile. Other yolked ova are fed on by the juveniles as ovulated (oophagy) or less developed embryos are eaten by the more developed ones (adelphophagy).… …   Dictionary of ichthyology

  • histotrophic live bearer — a reproductive guild (q.v.) where eggs develop into embryos and young whose partial or entire nutrition and gas exchange is supplied by the parent via histrotrophes …   Dictionary of ichthyology

  • internal live bearer — an ecological group with several reproductive guilds (q.v.) where eggs are fertilised internally and young are born alive …   Dictionary of ichthyology

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