The blue catfish is one of the biggest species of catfish in North America. It is bluish-gray in color with a white belly. They have a forked tail, very smooth skin with no scales, and a wide head. Blue Catfish have a dorsal hump near the center of their back
Koi fish are freshwater fish that come in a variety of colors, not just orange. Most koi fish can grow up to three feet long and may have a lifespan of 30 to 60 years, and in the right conditions can reach 200+ years.
There are several well-known and popular types of carp: goldfish, common carp, koi and grass carp. In the wild, carp fish tend to have duller colors such as brown, green, silver, black, and white, however occasionally, a brighter orange or red carp will arise.
Koi come in a variety of colors. Some can be white, black, blue, red, cream and yellow in color. They can also be covered with different spots.
Koi fish are surprisingly intelligent. This allows koi parents to train their koi fish to eat from their hand and even ring a bell for a treat. Koi fish will recognize the persons feeding them and gather around them at feeding times.