Types Of Reproduction In Fishes. Smit Ramesh Lende 1 ,Ramchandra khileri 2.
In biology, reproduction is the process by which new individual organisms are produced. Reproduction is a fundamental feature of all known life; each individual organism exists as the result of reproduction. Although the term reproduction encompasses a great variety of means by which organisms produce new offspring, reproductive processes can be classified into two main types: Sexual reproduction and asexual reproduction.
The methods of reproduction in fishes are varied, but most fishes lay a large number of small eggs, fertilized and scattered outside of the body.
The eggs of pelagic fishes usually remain suspended in the open water. Many shore
How do fish reproduce sexually or asexually freshwater fishes lay eggs on the bottom or among plants. Some have adhesive eggs. The mortality of the young and especially of the eggs is very high, and often only a few individuals grow to maturity out of hundreds, thousands, and in some cases millions of eggs laid.
Males produce sperm, usually as a milky white substance called milt, in two sometimes one testes within the body cavity.
In bony fishes a sperm duct leads from each testis to a urogenital opening behind the vent or anus. In sharks and rays and in cyclostomes the duct leads to a cloaca.
Sometimes the pelvic fins are modified to help transmit the milt to the eggs at the female's vent or on the substrate where the female has placed them. Sometimes accessory organs are used to fertilize females internally-for example, the claspers of many sharks and rays. In the females the eggs are formed in two ovaries sometimes only one and pass from the ovaries to the urogenital opening and "How do fish reproduce sexually or asexually" the outside.
In some fishes the eggs are fertilized internally but shed before development takes place. Members of about a dozen families each of bony fishes teleosts and sharks bear live young. Many skates and rays also bear live young. In some bony fishes the eggs simply develop within the female, the young emerging when the eggs hatch ovoviviparous. Others develop within the ovary and are nourished by ovarian tissues after hatching viviparous.
There are also other methods utilized by fishes to nourish young within the female. In all live-bearers the young are born at a relatively large size and are few in number. In one family of primarily marine fishes, the surfperches from the Pacific coast of North America, Japan, and Korea, the males of at least one species appear to be born sexually mature, although they are not fully grown.
Some fishes are hermaphroditic, an individual producing both sperm and eggs, usually at different stages of its life. Self-fertilization, however, is probably rare. Successful reproduction and in many cases defense of the eggs and young is assured by rather stereotyped but often elaborate courtship and parental behaviour, either by the male or the female or both. Some fishes prepare nests by hollowing out depressions in the sand bottom cichlids, for examplebuild nests with plant materials and sticky threads excreted by the kidneys sticklebacksor blow a cluster of mucus-covered bubbles at the water surface gouramis.
The eggs are laid in these structures. Some varieties of cichlids and catfishes incubate eggs in their mouths. Some fishes, such as salmon, undergo long migrations from the ocean and up large rivers to spawn in gravel beds where they themselves hatched anadromous fishes. Others undertake shorter migrations from lakes into streams or in other ways enter for spawning habitats that they do not ordinarily occupy.
A from of reproduction that involves the fusion of two reproductive cells ova and sperm in the process of fertilization normally especially in animals, it requires two parents, one male and the other female. The female of the species produces an egg which is fertilized by sperm from the male.
Depending on the species, fertilization takes place either within the female's body or externally, after the female lays her eggs and the male releases his sperm close by. When the egg is fertilized the genes of both parents are combined to produce zygote which develops into a new individual.
Nearly all animals reproduce sexually. Which is the prevalent kind; sperm and eggs develop in separate male and female individuals.
Both sexes are in one individual and, as among certain errands and a dozen or more other families. Self-fertilization or true functional hermaphrodites sexists. Hermaphroditic sex glands are known for several species, including some trout relatives salmonoidsperches Percawalleyes Stizostedion.
And some of the black basses Micropterus. Reproduction in which new individuals are produced from a single parent without the formation of gametes. Asexual reproduction enables animals to reproduce without a partner.
It occurs chiefly in lower animals, microorganisms, and plants. Many invertebrates reproduce asexually, including coral and starfish. Coral How do fish reproduce sexually or asexually small buds that break off to become separate organisms, whilst starfish are able to generate an entirely new being from a fragment of their original body. Without above classification, another three types of reproduction are also possible. Is the development of young without "How do fish reproduce sexually or asexually," and a condition that has been called parthenogenesis more properly gynogenesis occurs in a tropical fish, the live-bearing Amazon molly poecilia Formosaand is also known in poeciliopsis.
Mating with a male is required, but the sperm serves only one of its two functions, that of inciting the eggs to develop; it does not take any part in heredity.
The resultant young are always females, with no trace of parental characters. Sexual reproduction is a process of biological reproduction by which organisms give rise to descendants that have a combination of genetic material contributed by two different gametes, usually i.
A gamete is a mature reproductive or sex cell. Sexual reproduction results in increasing genetic diversity, since the union of these gametes produces an organism that is not genetically identical to the parent s. Sexual reproduction is characterized by two processes: During meiosis, the chromosomes of each pair usually cross over to achieve genetic recombination. Once fertilization takes place, the organism can grow by mitosis.
While typically sexual reproduction is thought of in terms of two different organisms contributing gametes, it also includes self-fertilization, whereby one organism may have "male" and "female" parts, and produce different gametes that fuse. Sexual reproduction is the primary method of reproduction for the vast majority of visible organisms, including almost all animals and plants.
The origin of sex and the prominence of sexual reproduction are major puzzles in modern biology. Gametes, meiosis, fertilization, and mitosis. In the first stage of sexual reproduction, 'meiosis', a special type of that takes place in gonads prior to the a production of gametes, the number of chromosomes is reduced from a diploid number 2n to a haploid number n. During 'fertilization', haploid gametes come together to form a diploid zygote and the original number of chromosomes 2n is restored in the offspring.
Sexual reproduction involves the fusion or fertilization of gametes from
How do fish reproduce sexually or asexually different sources or organisms.
Typically, a gamete or reproductive cell is haploid, while the somatic or body cell of the organism is diploid. A diploid cell has a paired set of chromosomes.
Haploid means that the cell has a single set of unpaired chromosomes, or one half the number of chromosomes of a somatic cell.
In diploid organisms, sexual reproduction involves alternating haploid n and diploid 2n phases, with fusion of haploid cells to produce a diploid organism. Some organisms, however, exhibit polyploidy, whereby there are more than two homologous sets of chromosomes. Meiosis and mitosis are two diverse type of cell divisions. Mitosis occurs in somatic body cells. The resultant number of cells in mitosis is twice the number of original "How do fish reproduce sexually or asexually." The number of chromosomes in the daughter cells is the same as that of the parent cell.
Meiosis occurs in reproductive or sex cells and results in gametes. It results in daughter cells with half the number of chromosomes present in their parent cell. Essentially, a diploid cell duplicates it's chromosomes, then undergoes two divisions tetroid to diploid to haploidin the process forming four haploid cells. This process occurs in two phases, meiosis I and meiosis II.
Fertilization involves the fusion of haploid gametes to give a diploid organism, which can then grow by mitosis. Thus, in sexual reproduction, each of two parent organisms contributes half of the offspring's genetic makeup by creating haploid gametes that fuse to form a diploid organism. For most organisms, a gamete that is produced may have one of two different forms.