All fish have internal sexual organs, and some have evolved external organs as well. Female fish have ovaries that produce eggs while male fish have testes that produce sperm. … Some fish species produce fewer eggs and have developed methods to make sure the few eggs are fertilized.
Are fish born with all their eggs?
Most fish release thousands of eggs, scattering them in the water where the male fish fertilize them. … A few kinds of fish keep their eggs inside their bodies, so when they hatch they give birth to live young.
Do female fish always have eggs?
Most fish species spawn eggs that are fertilized externally, typically with the male inseminating the eggs after the female lays them.
Are female babies born with eggs in their ovaries?
A female baby is born with all the eggs that she will ever have. This is estimated to be around two million, but by the time a girl reaches puberty, this number has decreased to about 400,000 eggs stored in her ovaries.
How do male fish fertilize eggs?
The fertilization can be done in a number of different ways; either by the male rubbing his sexual organs on the eggs, releasing sperm, or releasing sperm into the water to join the eggs in the zooplankton layer (if the eggs have been laid in that way).
How long are fish pregnant for?
As examples, the female swordtail and guppy will both give birth to anywhere from 20 to 100 live young after a gestation period of four to six weeks, and mollies will produce a brood of 20 to 60 live young after a gestation of six to 10 weeks.
Which fish does not lay eggs?
Among aquarium fish, livebearers are nearly all members of the family Poeciliidae and include guppies, mollies, platies and swordtails. The advantages of livebearing to the aquarist are that the newborn juvenile fish are larger than newly-hatched fry, have a lower chance of mortality and are easier to care for.
Are my fish fighting or mating?
If the fish are fighting, they will tend to leave each other alone, but if they’re mating, you will typically see them together or with their eggs. Fertilized eggs are clear and unfertilized eggs are white in color.
Why are my fish chasing each other?
Chasing behavior can be of three types: male rivalry to determine dominance, males courting female fish to mate, and females chasing male fish. In this last case females may either want to show they are ready to mate, or want to chase away over-eager male fish.
How do female fish produce eggs?
Reproduction is different depending on the species but generally happens one of three ways. In most cases, the female drops eggs in the water which are immediately fertilized by sperm from the male. Another way is for fertilization to occur within the females body before she drops them into the water.
How many babies can a woman have in her lifetime?
One study estimated a woman can have around 15 pregnancies in a lifetime. And depending on how many babies she births for each pregnancy, she’d probably have around 15-30 children. But the “most prolific mother ever,” according to Guinness World Records, was Mrs. Feodor Vassilyev in 19th century Russia.
Can you see your egg in your period?
The eggs are super tiny — too small to see with the naked eye. During your menstrual cycle, hormones make the eggs in your ovaries mature — when an egg is mature, that means it’s ready to be fertilized by a sperm cell. These hormones also make the lining of your uterus thick and spongy.
Does the left ovary produce a girl?
In the normal female the ovary of the right side yields ova which on fertilization develop as males, and the ovary of the left side yields ova which are potentially female.
Can human sperm fertilize fish eggs?
Well, the short answer is no. Both animals and plants have evolved extensive mechanisms which prevent this from happening. First, sperm have to find their way to an egg. In mammals, when the egg is released from the ovary it is surrounded by a loose group of follicle cells.
Do fishes cry?
“Since fishes lack the parts of the brain that set us apart from the fishes — the cerebral cortex — I doubt very much that fishes engage in anything like crying,” Webster told LiveScience. … “And certainly they produce no tears, since their eyes are constantly bathed in a watery medium.”
Do fishes pee?
Fish have kidneys which produce urine containing ammonium, phosphorus, urea, and nitrous waste. The expelled urine encourages plant growth on coral reefs; downstream benefits also include increased fertilization of algae and seagrass, which in turn provides food for the fish.