Fish can be classified in many different ways: by their shape, color, size, or where they live. But one of the most important classifications is how they reproduce. Do fish lay eggs or give birth?
Do Fish Lay Eggs or Give Birth
Fish can lay eggs, give birth to live young, or a combination of both. The way a fish reproduces affects its life cycle and the way it interacts with its environment.
Fishes Lay Eggs
Fishes are oviparous animals that give birth to their young ones through eggs. These eggs are generally laid in water where the fishes live and hatch after a specific incubation period.
Fishes lay eggs as a mode of reproduction. Eggs are generally laid in water, and the young hatch after fertilization from the eggs and grow into adult fishes.
The eggs are fertilized and hatch outside of the mother’s body. These eggs are often attached to underwater plants or structures.
How Do Fish Lay Eggs?
In the animal world, there are different ways in which eggs are laid. Some animals lay their eggs on the ground, some bury their eggs, and others lay their eggs in nests.
Fishes have evolved many different ways to lay eggs, from a simple scattering of eggs to complex spawning behaviors.
–There are a few different ways that fish can release their eggs. Some fish will release them by swimming through the water with all of their might.
–Other fish will use what is called a spawning nest. Spawning nests are made up of bubbles and mucous that the fish create themselves.
This nest helps to protect the eggs from being eaten or harmed by other predators in the water.
Where Would A Fish Lay Eggs?
A fish’s eggs can be laid in a number of different places, depending on the species. So do fish lay eggs in water?
Some lay their eggs in open water, some lay their eggs on the bottom of the river or lake, and some lay their eggs among plants. Some even secrete an adhesive that holds the eggs in place.
How Do Fertilization Occured After Laying Eggs in Water
Fish are a little different than other animals when it comes to laying their eggs.
Fish actually lay their eggs outside of their body in water or hard above the hard substrate.
At the same time, sperm is then released into the water by male fish and travels to the eggs, where fertilization occurs. The process is known as external fertilization.
This process occurs in most types of fish, with a few exceptions. External fertilization in water occurs when sperm and eggs are released into the environment and mix together to form embryos.
This process is common in fish, as they often release their eggs and sperm into the surrounding water.
Some fish, such as salmon, even migrate long distances upstream to find the perfect spot to reproduce.
How Often Do Fish Lay Eggs?
The time of year can also play a role in how often a fish will lay eggs. For example, many fish that spawn in the springtime do so multiple times throughout the season.
Fishes Give Birth
Other fish give birth to live young that are born inside the mother’s body and then swim away once they’re free-swimming. The process of giving birth is quite different from other animals.
Some fish even have a combination of both methods which is known as ovoviviparous.
The eggs of some species of fish (eg., sharks) develop into fry inside the body of the mother fish while others are released into open water as independent free-swimming organisms.
Most fishes feed their young ones with parental care but there are also those that simply release their eggs and leave them to fend for themselves.
Sharks have been known to give birth to live young sharks. The gestation period for a shark is typically about 9 months, but some species of sharks can have a gestation period as long as 18 months.
Sharks give birth to anywhere from 1-15 pups, depending on the species. Some sharks, such as the great white shark, have been known to cannibalize their own young.
Some species, including the hammerhead shark, are able to give birth to live young without laying eggs first. Young sharks feed on their mothers’ unfertilized eggs until they are ready to be born.
Over 97 percent of all species of fish are egg-laying, as eggs hatch independently in nature and are fully-formed juveniles. Three other types of fish are considered “live-bearers” because they resemble they are giving birth to fully formed juveniles.
Of the 3, some fish species are ovoviviparous. i.e. After internal fertilization, the eggs develop inside the mother’s body.
Examples of these are Livebearing fish species such as Guppies and Mollies, where the males have such a structure known as the ‘gonopod’ to defend themselves when reproducing.
Other marine species are live-bearing. After internal fertilization, the eggs develop inside the mother inside a sort of placenta, siphoning nutrients off the mother’s bloodstream. An example of these fish are the carnivorous half-beaks.
Oviparity: A reproductive mode in which a female lays unfertilized eggs or developing eggs in the external environment and lays the eggs off when they complete their development. Egg retention is also known as “egg laying” reproduction.
Ovoviviparity: An archaic term, now infrequently used, used to refer to a wide range of reproductions including ones that involve mutually exclusive reproductive methods, including lecithotrophic viviparity, oviparous egg retention, and pseudo viviparity.
pseudo viviparity: An odd oviparity style in which eggs are fertilized externally and brooded in parental structures such as the alimentary canal, vocal sacs, fur sacs, branchial chambers, or gastrovascular cavity; seen in a few salamanders, teleosts, and invertebrates.
Viviparity: A reproductive mode in which females retain their developing eggs in their reproductive tracts and give birth to their offspring; also called “live-bearing” reproduction.
It has been known that fish lay eggs, which hatch when carried outside the body of their mother; yet, are there fish that give birth and become pregnant with their own eggs?
If you breed fish in aquariums, you can see that guppies, also known as million fish and rainbow fish, hold their eggs inside their bodies. When the eggs hatch, the mother gives birth to water-living young fish.
The guppies always have their lives young inside their bodies, and this is what distinguishes them from other fish species. Professional breeders recognize the early signs of pregnancy in a guppy, such as weight gain and can turn into a dark spot on the tail.
Once the female becomes 2200 little fry, also known as fry, she drops them between four and six hours, and sometimes even more time in special cases.