Yes, many fish species lay eggs in fish tanks. However, some fish give birth to live young.
Whether or not fish lay eggs in a fish tank depends entirely on the species of fish. Some fish are egg-layers (oviparous), while others are livebearers (viviparous).
Here's a breakdown:
-
Egg-laying fish (Oviparous): These fish release eggs into the water, which are then fertilized externally (usually by the male). The eggs then hatch into fry. Many common aquarium fish, like tetras, goldfish, and danios, are egg-layers. Some egg-laying fish exhibit parental care, such as building nests or guarding the eggs.
-
Livebearing fish (Viviparous): These fish carry their eggs internally. The eggs are fertilized inside the female, and the young develop within her body. She then gives birth to live, free-swimming fry. Common examples of livebearers include guppies, mollies, platies, and swordtails.
In a fish tank, if you have egg-laying fish, you may find eggs deposited on plants, rocks, or the substrate. Livebearing fish will give birth to their young directly into the tank.
