Photo courtesy of Kate GardinePhoto courtesy of Kate GardineClose up of a Bighead:  Photo courtesy of Kate Gardiner



As a species, Bighead carp go through sexual reproduction as many other organisms do. In order to fully understand the details of how these fish go about reproducing there will be a brief introduction of terms that can further describe this process.

Asian carp minnows - Photo courtesy of the US Fish & Wildlife ServiceOne of the recognizable traits that Bighead carp have is they can be classified as gonochoristic.  The basic definition of the term means that an individual organism will only represent one type of sex with those sex reproductive organs only.  Another common word for this trait is dioecious, a latin word for two  households.  Thus, the male and female sexes are found in "two households" or separate individuals.

Not only are these fish gonochoristic, but they are considered synchronous fish.  Synchronous fish are found to spawn all at the same time as a species. 

What is spawning though?Photo courtesy of Adam Lohmeyer  Spawning is simply external fertilization taking place where females lay the eggs and males will fertilize them externally.  Spawning also requires specific conditions and will vary from species to species.  Bighead carp are considered semi-migratory, which means that they will migrate from  their lakes and  "lower ends" of rivers to move toward rivers and other spawning grounds "up stream".  Bighead carp often prefer areas with consistent water flow with velocities averaging around .6 to 2.3 meters per second  and water that is typically murky.  Once a location is reached females will lay a large number of eggs for the male to fertilize.  It is estimated that a female can lay between 200,000 to 1 million eggs in a lifetime.Photo courtesy of Kate Gardiner

The moving water where eggs are spawned keeps them afloat as they move downstream.  The embryo is much smaller than the entire egg.  This difference in size/mass ratio allows the egg to take in more water, helping maintain a low density which keeps the egg afloat.  As larvae hatch they will continue to drift with the current until they are strong enough to swim on their own, but it often takes 100 hours or more before this occurs.

Minnow - Photo courtesy of Adam Lohmeyer

An advantage for Bighead carp is their ability to grow very quickly if conditions permit them too.  A male will already be sexually mature after about 2 years, but females often require 3 years of age before they can reproduce.

Whether young or old there is no doubt that this interesting impact on the environment around it.  Click here to find out exactly how this species interacts with other organisms and learn  why Bighead carp get so much attention by the government and media in the United States and the rest of the world!


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