how do fish reproduce?
487322
The eggs of fish are fertilized either externally or internally, depending on species. The female usually lays the eggs and the embryos in the eggs develop and hatch outside her body. This kind of fish are called oviparous fish. Oviparous fish develop being obtaining food from the yolk in the egg. Salmon, for example, are oviparous. Ovoviviparous fish keep the eggs inside of the mother's body after internal fertilization. Each embryo develops in its own egg. The young are "born alive" like most mammals. Some species of fish, such as various sharks, are viviparous. Viviparous fish allow their embryos to stay in the mother's body like ovoviviparous fish. However, the embryos of viviparous fish obtain needed substances from the mother's body, not through material in the egg. The young of viviparous species are also "born alive".
193970
>Reproduction occurs both sexually and by asexual budding. Sexual reproduction is by means of eggs and sperm, which are produced in the mesentaries and shed into the water. Fertilization results in a free-swimming larva, which attaches to a surface and secretes a skeleton, becoming (in colonial forms) the parent of a new colony.
720118
"Females release thousands of transparent eggs in jelly-like strands into the water. \n Take a close look at a developing squid, or paralarva. It looks like a miniature adult. \n\nMales produce long tubes, or spermataphores, filled with millions of sperm. Most species have a modified arm for depositing these in or on the female. This spermataphore cluster is implanted on the head of a female (Abraliopsis sp.). No wonder scientists are puzzled as to how squid eggs get fertilized!"
1104737
During bird breeding season, in response to hormones from the pituitary gland , the male's testes become several hundred times larger than normal to produce sperm, with the left testis usually larger. The female bird's ovaries also enlarge during breeding season to produce the ovum. \n\nIn birds, an ovum is fertilized in the female bird's oviduct by a sperm cell from the male bird. Once fertilized, the ovum becomes the nucleus of the egg. The egg, that has its own food source, the yolk, will be laid by the female into her nest, incubated, and then the baby bird will hatch.\n\nBut how does the sperm from the male bird get into the female? How can they have intercourse without any external male organs, such as a penis? The male's sperm, produced in the testes, passes to the cloaca where it is stored until copulation (act of sex). The female also has a cloaca that leads from the ovaries. The female bird unfans her tail, moves it to one side while the male climbs up onto her back or gets close to her. Their cloacas are pressed together and the sperm moves from the male to the female. This act is called a cloacal kiss. \n\nThe sperm is stored by the female for at least a week, in some species over a hundred days. Then as each ovum from the ovary moves into the oviduct, it gets fertilized with the stored sperm, producing a clutch of many eggs, all with the sperm from that one cloacal kiss.\n\nThere are a few species of birds where the males do possess a retractable penis that can be pulled back into the bird. These birds include ostriches, cassowaries, kiwis, swans, geese, and ducks. Since waterfowl sometimes make love while in the lake or pond, the penis helps ensure that the sperm is not washed away by the water.\n\nSperm can be transferred from male cloaca to the female in a blink of an eye - less than a second. Some birds seem to want to linger longer though, sometimes having sex for more than an hour! And, although it is not necessary to copulate frequently since the sperm is stored within the female, remember those hormones are still making the birds excited. Many pairs of birds will mate numerous times within a few days.
448554
they use gills. the gills are filled with lots of blood vessels.  the fish draws in water from the mouth, which passes by and out the gills. as the water moves by, the blood cells take in oxygen and the waste gases are released.
480132
Basically, plants reproduce like most other organisms... sexually.  The main difference is that their young (seeds-to-be; ovules?) grow either inside a receptacle, or fruit, (angiosperms) or without a receptacle (gymnosperms).
262929
Triploid fish are fish that have three sets of chromosomes in their cells, instead of the usual two (diploid) set most animals have.\n\nTriploid fish are usually sterile (the extra chromosomes really mess up the generation of sperm or eggs).  Because they are sterile, they have been used in some fish farms to reduce the danger to the environment if the fish escape.\n\nHowever, the triploid fish tend to be less resistant to disease and often have physical abnormalities that reduce their ability to thrive (they tend to be a tad gibbled in other words).
583308
Good question.  Some come out immediately after sex.  Yet others (millions of those little jokers) swim until one attaches itself to an egg.  After that, the rest 'die' and are  expelled out of the woman's body over time.
77951
There are many different types of "sex" practiced in the plant and animal kingdoms besides the type we humans are familiar with. There are species in which the fathers get pregnant (like seahorses). There are species where males will turn into females (or vice-versa) if it would help the species survive. There are lots of examples of parthenogensis (virgin birth). There are cases where a single individual (like a plant) will pollinate itself, but others where biology tries to prevent this, although the plant might be hermaphroditic. There are plants which have several different reproduction mechanisms; a piece of the root can produce a new individual, for example. Some organisms can engage in both sexual and asexual reproduction as well; earthworms, honeybees, and geckos can asexually reproduce. There are species with 3 or even more sexes (like the clam shrimp in the US, for example, which has 3 sexes, or possibly  the New Zealand lizard the tuatara, which appears to have 4 sexes. There are species where males just fertilize the eggs deposited by the female in some location (most fish). Bacteria and viruses reproduce in strange ways, by dividing, or by taking over the reproduction mechanism of some other organism. \n\nThe astounding variety of "sex" and/or reproduction just goes on and on and on. We are still learning about the amazing diversity of life on this planet. \n\nIf and when we ever discover life on other planets, you can be sure that they will have different ways to reproduce, that may or may not have anything to do with what we might recognize as sex, and probably using mechanisms we cannot even imagine.
392040
Hope this sheds some light on it jessica.\n\n\nREPRODUCTION\n\nMost fishes are egg-layers, but many bear living young. Live-bearing fishes may be ovoviviparous, in which the eggs essentially simply hatch within the female, or viviparous, in which the unborn young are supplied nourishment through the mother's tissues. In some ovoviviparous fishes the embryo develops in the egg while the egg is still within its follicular covering within the ovary, and ovulation (or release of the egg) and birth occur at the same time. In other ovoviviparous forms the eggs are released from the protective follicles into the cavity of the hollow ovary, where development continues. In some viviparous fishes the walls of the egg follicle are in intimate contact with the embryo, supplying it with nourishment. In the viviparous sharks, a part of the oviduct, or egg channel, is developed into a uterus, where the modified yolk sacs of the young are closely joined to pockets within the uterus.\n\nIn live-bearing fishes and in some egg-layers, fertilization occurs internally, and methods have been evolved for introducing the sperm into the female's body. In sharks the pelvic fins of the male are modified into intromittent organs called myxoptergia, and in the male topminnows the anal fin is modified into a similar-functioning intromittent organ called the gonopodium.\n\nAt least three modes of reproduction--heterosexual, hermaphroditic, and parthenogenetic--are found in fishes. In the most common form, heterosexual reproduction, there are separate male and female parents, but even here there is considerable variation. In some live-bearing fishes, the female is able to store sperm for up to 8 or even 10 months, and this sperm is used to fertilize new batches of eggs as they develop. In some cases, a female may carry sperm from several males at once.\n\nIn hermaphroditic reproduction, a single fish is both male and female, produces both eggs and sperm (either at the same time or at different times), and mates with other similar hermaphroditic fishes. External self-fertilization occurs in one hermaphroditic fish, which sheds egg and sperm simultaneously. In another, internal self-fertilization may occur. In certain fishes there is a time sequence of hermaphroditism, young fishes reversing their sex as they grow older.\n\nIn parthenogenetic reproduction, unfertilized eggs develop into embryos. This is known to exist in at least one fish species, Poecilia formosa, of the Amazon River; however, even though development proceeds without fertilization in some of these females, mating with a male is still required to stimulate egg development.\n\nParental care also shows great diversity. Some fishes, like the Atlantic herring, form huge schools of males and females and freely shed their eggs and sperm (milt), and then abandon the eggs. Other fishes build nests and care for both the eggs and newly hatched young. Others have evolved methods of carrying the eggs with them, commonly in their mouths, but also in gill cavities or in special pouches on the body.
16739
It depends on the fish.  Salmon are spawned in fresh-water lakes and swim to the sea only to return as adults up rivers and dams to their birth lakes to repeat the cycle.  Some fish live in brackish water that is part fresh and part salt water which changes with the tides.  Some fish cannot adapt from fresh to salt water or vice versa.
590323
Reproduction System:  Depending on the species some clams are either females or males.  Both the eggs and sperms are released into the water.  Some clams are hermaphroditic which means the clam has both male and female reproductive organs.  In the species that fertilization takes place externally, the zygote develops into a swimming larva, trochophore (Alexander 439).  In some freshwater clams the young is carried inside the female's gills for a period of time.  Reproduction can occur at two different times of the year.  "long term brooders or winter brooders" spawn basically in August to October and carry the young all winter long.  The "short tem brooders or summer brooders" spawn during the summer and the young is carry for a few weeks.  After a certain period of time are discharge from the female mussels and become parasites on fish fins, gills, and external surfaces.  This stage may last up to six weeks (Harris and Gordon 2)
301358
Nearly all animals undergo some form of sexual reproduction. Adults are diploid or occasionally polyploid. They have a few specialized reproductive cells, which undergo meiosis to produce smaller motile spermatozoa or larger non-motile ova. These fuse to form zygotes, which develop into new individuals.\n\nMany animals are also capable of asexual reproduction. This may take place through parthenogenesis, where fertile eggs are produced without mating, or in some cases through fragmentation.\n\nA zygote initially develops into a hollow sphere, called a blastula, which undergoes rearrangement and differentiation. In sponges, blastula larvae swim to a new location and develop into a new sponge. In most other groups, the blastula undergoes more complicated rearrangement. It first invaginates to form a gastrula with a digestive chamber, and two separate germ layers - an external ectoderm and an internal endoderm. In most cases, a mesoderm also develops between them. These germ layers then differentiate to form tissues and organs.\n\nAnimals grow by indirectly using the energy of sunlight. Plants use this energy to turn air into simple sugars using a process known as photosynthesis. These sugars are then used as the building blocks which allow the plant to grow. When animals eat these plants (or eat other animals which have eaten plants), the sugars produced by the plant are used by the animal. They are either used directly to help the animal grow, or broken down, releasing stored solar energy, and giving the animal the energy required for motion. This process is known as glycolysis.
226498
A dolphin reproduces by laying belly to belly. The female is on top and the male swims beneath her. She will usually mate with several males in one season. This is thought to believed to be a strategy to help protect her young. Male dolphins sometimes get aggressive towards calves and may even kill them if they are not their own. By mating with several males, the female as well as the male(s) have no idea who the father is, and is less likely to attack a baby.
179270
They mate for life.\nThey shed like a snake.\nThey can, in fact, be blue.\nThe females carry the eggs on their sides.\nThey swim backwards.\nThey're cute. ;3;
959644
some frogs, fish and shellfish are capable of this.\n\ni dont believe that any mammals can.\n\nIt seems to me that the ones that can do this are usually they type that release their eggs and spem with no consideration of who fertilizes them
1020949
During mating season, males may court a female by nuzzling her head or by gently biting the back of her neck and rear flippers. If the female does not flee, the male attaches himself to the back of the female's shell by gripping her top shell with claws in his front flippers. He then folds his long tail under her shell to copulate. \n\nFemales observed on the nesting beach after recently mating often have scratched shells and may be bleeding from where the males' were hooked to their shells. Copulation can take place either on the surface or under water.