Spoil your Koi and other big eaters with color-enhancing Krill (Euphausia superba) is similar nutritionally to its cousin, Euphausia pacifica, but is about two to three times the size, or approx. 1 to 1.5 inches in length. Krill is a rich source of carotenoids, including astaxanthin, that will bring out the colors in both marine and freshwater fish. Proper handling and low-temperature drying keeps natural flavourants, proteins and lipids largely intact. Powerful flavourants contained in krill act as an attractant to many species of fish. The use of krill as a feed supplement is especially helpful to develop a feeding response in many fish.