Not all Grass Carp hit the news

[MuskieBait]

Wow...so much scientific inaccuracy here!

Common Carp (Cyprinus carpio)

Goldfish (Carassius auratus)

"Asian Carp"

Grass Carp (Ctenopharyngodon idella)

Black Carp (Mylopharyngodon piceus)

Silver Carp (Hypophthalmichthys molitrix)

Bighead Carp (Hypophthalmichthys nobilis)

Goldfish is a distinct species that arise from domestication from Prussian Carp (Carassius gibelio), much like the Cat (Felis catus) became a distinct species from domestication from the Wildcat (F. silvestris) and its subspecies.

Goldfish is NOT bred from the Common Carp.

Goldfish can hybridize with Common Carp, and has been known to do so naturally. I have caught hybrids in Ontario. However, Goldfish x Common Carp do not revert back to Common Carp only. The reversion is based on genetic dilution of the back crosses based on the parent of the crosses. If the hybrid breeds with a Goldfish, and successive generations continues to breed with Goldfish, then eventually the Common Carp genetics is bred out. On the other hand, if the back cross is done with Common Carp generations after generations, then the Goldfish contribution will be bred out. If the hybrids breed with other hybrids, the successive generations remains as hybrids.

Even in domestic form, any batch of Goldfish will include "wild" (grey/green) individuals. No clutch is ever pure. The same occurs in Koi, the domesticated and selected form of Common Carp. Any clutch of Koi will contain "wild" individuals. There is a lot of culling in the aquarium trade for individuals with ideal colour and patterns.

While colours tend to vary, other features like tail shape, fin sizes and scale pattern seems to breed more true between generations.

By convention, "Asian Carp" refers to 4 different species, of which two are closely related. Among these, only Silver and Bighead Carp are known to hybridize naturally, but not often. Grass Carp x Bighead Carp has been artificially hybridized in the lab, but not known to hybridize in the wild.

I despise the term "Asian Carp" as it conglomerate 4 different species that behave completely differently with varying level of invasive threats. It is unscientific to describe these 4 species and only serve to create fear mongering every time the term is used. It also promote poor public understand of these species as proven above. The level of inaccuracies demonstrated on fishing forums about the behavior and threat is rampant.

In short, Goldfish does not equal domesticated Common Carp, and it certainly does NOT give rise to "Asian Carp".

This kind of comment is like saying the Cat is a domesticated Bobcat (Lynx rufus), and the Cat can give rise to the "Big Cats" such as Lion (Panthera leo) and Snow Leopard (Uncia uncia) when they are released into the wild and go feral. It's just ridiculous.