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The female then extrudes eggs, which pass through the spermatophores. The female carries the fertilized eggs with her until they hatch; the time may vary, but is generally less than three weeks. A large female may lay up to 100,000 eggs. From these eggs hatch zoeae, the first larval stage of crustaceans. They drift towards brackish waters where ...
The eggs have an average diameter of 1 millimetre (0.039 in). The eggs are generally surrounded by the extraembryonic membranes but do not develop a shell, hard or soft, around these membranes. Some fish have thick, leathery coats, especially if they must withstand physical force or desiccation. These type of eggs can also be very small and ...
Because the newborn fish are large compared to the fry of oviparous fish, which are those that lay eggs, newborn fish of livebearers are easier to feed than the fry of egg-laying species, such as characins and cichlids. This makes them much easier to raise, and for this reason, aquarists often recommend them for beginning fish breeder hobbyists.
Fish farming or pisciculture involves commercial breeding of fish, most often for food, in fish tanks or artificial enclosures such as fish ponds. It is a particular type of aquaculture , which is the controlled cultivation and harvesting of aquatic animals such as fish, crustaceans , molluscs and so on, in natural or pseudo-natural environments.
A fish hatchery is a place for artificial breeding, hatching, and rearing through the early life stages of animals—finfish and shellfish in particular. [1] Hatcheries produce larval and juvenile fish , shellfish , and crustaceans , primarily to support the aquaculture industry where they are transferred to on-growing systems, such as fish ...
Assynt salmon hatchery, near Inchnadamph in the Scottish Highlands Very young fertilised salmon eggs, notice the developing eyes and vertebral column. Salmon egg hatching: In about 24 hr, it will be a fry without the yolk sac. The aquaculture or farming of salmonids can be contrasted with capturing wild salmonids using commercial fishing ...
A pregnant Southern platyfish. Pregnancy has been traditionally defined as the period of time eggs are incubated in the body after the egg-sperm union. [1] Although the term often refers to placental mammals, it has also been used in the titles of many international, peer-reviewed, scientific articles on fish.
Some fish have evolved to exploit the mouthbrooding behaviour of other species. Synodontis multipunctatus, also known as the cuckoo catfish, combines mouthbrooding with the behavior of a brood parasite: it eats the host mouthbrooder's eggs, while spawning and simultaneously laying and fertilizing its own eggs. The mouthbrooder (typically a ...