Live-bearing aquarium fish, often simply called livebearers, are fish that retain the eggs inside the body and give birth to live, free-swimming young.

Live-bearing aquarium fish, often simply called livebearers, are fish that retain the eggs inside the body and give birth to live, free-swimming young.

Most reptiles are oviparous ( egg-laying ), although certain species of squamates retain the eggs until hatching and a few are viviparous ( give birth to live young ).

In most decapods, the females retain the eggs until they hatch into free-swimming larvae.

German Protestants wanted to retain the Catholic custom of eating colored eggs for Easter, but did not want to introduce their children to the Catholic rite of fasting.

However, a female bearded dragon can retain sperm, and thus produce fertile eggs even after being separated from a male.

Other research indicates that juveniles are deeply curious about all new things, and that Common Ravens retain an attraction to bright, round objects based on their similarity to bird eggs.

Two genera of labrisomid are noted for their ovoviviparity ; Xenomedea and Starksia both retain eggs within the oviduct where they develop in safety.

A clutch consists of 2-8 eggs, which retain a cinnamon color for most of the gestational period, but develop brown spots just prior to hatching.

Fertilized duck eggs are kept warm in the sun and stored in baskets to retain warmth.

All members of this family retain eggs that hatch within the body of the mother ( ovoviviparous ).

As recently as 1957 it was found that the females do not deposit eggs in the bottom ooze, but retain the developing embryos within their bodies so that they are born alive after an undetermined gestation period.

Females may be able to retain sperm, and females held in confinement have been able to lay fertile eggs.

Although the whole family Poeciliidae is known as " live bearers ", there are egg-scattering species with external fertilization in addition to the true live-bearing viviparous and ovoviviparous species, which have internal fertilization and the eggs hatch before being laid, so the female gives birth to live young.

The eggs hatch into aquatic larvae, called tadpoles, that have internal gills and tails.

Fertilisation is internal, and the eggs are released by rupture of the body wall.

Reproductively, they are dioecious, with the internal fertilization of eggs that are then laid in gelatinous strings.

They are best known for building massive nest-mounds of decaying vegetation, which the male attends, adding or removing litter to regulate the internal heat while the eggs hatch.

In the field, scientists obtain contaminant measurements from eggs, feathers or internal organs.

This includes external factors as appearance ( size, shape, colour, gloss, and consistency ), texture, and flavour ; factors such as federal grade standards ( e. g. of eggs ) and internal ( chemical, physical, microbial ).

The California Kingsnake is an oviparous internal fertilization animal, meaning it lays eggs as opposed to giving live birth like some other snakes.

In most anurans the males deposit sperm onto the eggs as they are being laid, however males of the genus Ascaphus possess an intromittent organ, unique among anurans, for internal fertilization.

* Oviparity: fecundation is internal, the female lays zygotes as eggs with important vitellus ( typically birds )

* Oviparity: fecundation is internal, the female lays zygotes as eggs with important vitellus ( typically birds )

In the mating season, each race of slaad converges on the Spawning Stone, wresting the Stone away from the previous group, so that they may fertilize each other's internal egg sacs, and carry away the seed-like fertilized eggs for later implantation into host bodies.

Chimaeras resemble sharks in some ways: they employ claspers for internal fertilization of females and they lay eggs with leathery cases.

Fertilization in five-lined skinks is internal, with eggs laid by the female between the middle of May and July, at least one month after mating.

Many parasitic disease specialists are seeing increased incidence and recurrence of roundworm in the U. S. and are thereby increasingly recommending follow up courses of medication to treat internal eggs which have not yet hatched, in addition to the initial treatment period as above.

They leave their hosts for up to three weeks in order to mate and lay eggs, and reattach behind the fish's operculum, where they feed on mucus and sloughed-off scales, or pierce the skin and feed on the internal fluids.

* Oviparity: fecundation is internal, the female lays zygotes as eggs with important vitellus ( typically birds )

Land-dwelling animals that lay eggs, often protected by a shell, such as reptiles and insects, do so after having completed the process of internal fertilization.

Possible reproductive modes include full amphibian spawning with aquatic tadpoles, internal fertilization with or without ovoviviparity, aquatic eggs with direct development or some combination of these.

The black eggs are covered by a membrane and their diameter is approximately.

( The amniotes are the vertebrates with eggs featuring an amnion, a double membrane that permits the embryo to breath effectively on land.

* The majority of species are ovoviviparous: the medium-sized eggs, encased only by a double membrane, remain in the uterus.

Amphibians must return to water to lay eggs, in contrast, reptiles-whose amniote eggs have a membrane ensuring gas exchange out of water and can therefore be laid on land-were better adapted to the new conditions.

Up to 35 eggs are laid in a burrow, within a mucous membrane that preserves moisture.

Their eggs were small and covered with a leathery membrane, not a hard shell like those of birds or crocodiles.

The outer membrane, a soft shell, evolved as a protection against the harsher environments on land, as species evolved to lay their eggs on land where they were safer than in the water.

The eggs are surrounded by an adhesive membrane.

Five female Gonatus onyx squids have been observed in Monterey Canyon dragging a membrane sack containing 2, 000 to 3, 000 developing eggs.

The eggs are oval or elliptical, measuring 60 µm by 40 µm, colourless, not bile stained and with a thin transparent hyaline shell membrane.

The zona pellucida is a thick membrane that surrounds the unfertilized eggs of mammals.

Crocodile eggs are similar to those of birds in that they have an inner membrane and an outer one.

Some arthropod eggs do not actually have shells, rather, their outer covering is actually the outermost embryonic membrane, the choroid, which serves to protect inner layers.