Free Speakers
As free spawners or open water spawners are called fish that do not brood operate and release their eggs and sperm into the open water or plant populations. Free spawners can be found in almost all families of the bony fish (Osteichthyes). Brood care is the exception.
Schooling fish often spawn with multiple males and females. Many marine fish rise to the surface of the water. Due to their fat content, the eggs are just as heavy as the water and drift away with the plankton . In freshwater fish , the females often release their eggs above the sperm-expelling males. The eggs sink to the bottom, pass the water zone that is saturated with sperm, and are fertilized in the process.
The number of eggs released by free spawners is usually very large (1000 and more for freshwater fish, and millions for large marine fish). The eggs are mostly colorless and inconspicuous. A very simple form of brood care is considered to be the spawning migration, which is undertaken by many species of fish in order to get to areas that are particularly favorable for the development of the brood.
See also
literature
- Manfred Klinkhardt: Freedivers. In: Claus Schaefer, Torsten Schröer (Hrsg.): The large lexicon of aquaristics. Eugen Ulmer, Stuttgart 2004, ISBN 3-8001-7497-9 , p. 382.